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Effects of Nutrients and Hydroperiod on Typha, Cladium, and Eleocharis: Implications for Everglades Restoration
Abstract
The recent expansion of Typha domingensis (Typha) into areas of the Ev- erglades previously dominated by Cladium jamaicense (Cladium) communities has led to competing hypotheses about the importance of nutrient concentration vs. hydroperiod in controlling the distribution of these species. In this study, experimental mixtures of Typha domingensis, Cladium jamaicense, and Eleocharis interstincta (Eleocharis), a member of the Cladium community, were subjected to two levels of nutrient concentration and three contrasting hydroperiods to determine how these variables might affect Tjpha's ability to displace the Cladium community. Mixtures of the three species were established in outdoor tanks containing soil from the northern Everglades region where the experiment was con- ducted. Nutrient treatments consisted of nutrient additions to adjust ambient water con- centrations to either 50 pg/L phosphorus (P) or 100 pg/L P plus nitrogen (N). The three hydroperiods were achieved by maintaining water depths within ranges observed in the northern Everglades. Maximum water depths of 15,30, and 60 cm were established through- out the wet season (May-November) followed by lowering to 5 cm during the dry season. Over a 2-yr period, biomass was monitored nondestructively and aboveground material was harvested at the end of the experiment. Analysis of the biomass changes over time showed that differences between the species developed by the end of the first growing season. Typha and Eleocharis had initial growth rates substantially higher than those observed for Cladium. Typha's growth in mixtures responded positively to both elevated nutrients (by as much as 45%) as well as to increased water depth (by as much as 60%), while Cladium and Eleocharis did not increase in response to these variables. Tissue P concentrations were found to be higher for Typha and Eleocharis than for Cladium under nearly all conditions. Net accu- mulation of P in Typha shoots was 2-3 times greater than in the other species. The en- hancement of Typha by elevated nutrients and increased flooding is associated with a syndrome of life history characteristics that includes rapid growth rates, high tissue con- centrations of P, tall leaves, and a greater response to contrasting environmental conditions. Cladium, in contrast, showed a slow growth rate, low tissue concentrations of P, a greater capacity to resist invasion by Typha in shallow waters, and less of a growth response to contrasting environmental conditions, traits that would seem to be well suited to the nutrient- poor, hydrologically unstable conditions natural to the Everglades. Results from this study suggest that attempts to limit the spread of Typha should consider hydrologic restoration as well as reduction in surface water nutrients.
... Phragmites australis is recognised as a particularly problematic species with a complex genetic structure and global distribution of distinct haplotypes (Canavan et al., 2018;Packer et al., 2017), and some haplotypes of T. domingensis have been introduced beyond their native range (Ciotir & Freeland, 2016). Both Phragmites and Typha are most productive and sometimes form monodominant stands in disturbed, fertile and flooded habitats (Davis, 1991;Osland et al., 2011;Saltonstall & Stevenson, 2007), from desert oases (Lewis & Packer, 2020) and semi-arid rivers (Deegan et al., 2012) to tropical wetlands (Newman et al., 1996). ...
... The restricted range of these species may be due to their limited ecological amplitudes and adaptation to nutrient-enriched conditions associated with disturbed habitats (Thompson et al., 2005). Although C. procerum and C. gymnocaulos are most productive in flooded, nutrient-enriched habitats with stable flows (Deegan et al., 2012), their shorter stature suggests they may be less productive, and potentially less plastic, than P. australis (Canavan et al., 2018;Deegan et al., 2012) and T. domingensis (Newman et al., 1996). ...
... Understanding which species can protect (Read & Stokes, 2006) and/or store resources (Grime, 1977) in their below-ground biomass during flooding disturbanceand the mechanisms they use -may help to inform the removal of barriers to natural flooding. The removal of barriers to naturally fluctuating flows, such as dams and lock gates or surface-flow drains, could reduce the performance of homogenising monodominant species (Moles et al., 2012;Newman et al., 1996;Packer et al., 2017). The effect on endemic species, however, is less clear. ...
Plant communities within many of the world’s waterways are losing diversity where flows are stabilised for security and enriched from land-use intensification. Understanding the phenotypic plasticity of plant species that protect and/or store their below-ground biomass during floods may help to promote them if problematic, overabundant species – like Phragmites australis and Typha domingensis – are less plastic. To investigate mechanisms underlying the plasticity of two cosmopolitan (Phragmites, Typha) and two endemic (Cycnogeton procerum, Cyperus gymnocaulos) macrophytes in response to disturbance (fluctuating hydrological regimes) across a nutrient gradient, we analysed historical data from pond experiments with single-species pots. Our analyses showed fluctuating water levels in nutrient-enriched conditions reduced total biomass in all species, with 65% and 46% reduction in Phragmites and Typha respectively. Contrary to expectations, only Cycnogeton allocated a higher proportion of biomass to protect (root) and store (rhizome) resources in fluctuating water levels and nutrient-enriched conditions (45% versus 23% in stable regime), and was the most plastic by allocating 75% more biomass to belowground in the least favourable conditions. Our results indicate that removing impediments to stochastic flooding disturbance could benefit some endemic species while reducing the productivity of overabundant Phragmites and Typha in environments enriched by human activity.
... To protect the biodiversity from further deterioration, several Stormwater Treatment Areas (STAs) have been constructed at the northern end of the EPA to treat EAA runoff for P removal (Chimney and Goforth 2006). Current indicators of environmental changes for the Everglades as well as for other aquatic systems focus on the impacts of nutrient loading such as soil and water total P (TP) and total N (TN) concentrations, species composition, biomass, and primary production (Newman et al. 1996;Sklar et al. 2002Sklar et al. , 2005Wright et al. 2008). These indicators often reveal the changes in the impacted systems that have taken place. ...
... In contrast, the high δ 15 N A C B D at the impacted sites was due to P enrichment which leads to high N demand and low 15 N fractionation. Many studies have demonstrated that P is the limiting nutrient in the Everglades (Newman et al. 1996;Smith et al. 2009). Recent studies using stable isotopes found a positive relationship between TP and δ 15 N of periphyton, sawgrass, and cattail in WCA-1 and WCA-2A, which was attributed to P-driven plant growth and reduced isotope fractionation (Inglett and Reddy 2006;Chang et al. 2009). ...
... Responses of cattail δ 13 C and δ 15 N to changes in hydropattern Water depth and duration may affect the growth of aquatic plants which in turn affects tissue δ 13 C and δ 15 N. Newman et al. (1996) demonstrated that water depth and duration of flooding significantly impact cattail expansion in two south Florida wetlands. In the Everglades, marsh typically has shallower water depth and shorter hydroperiod than canals. ...
Abstract Background Florida’s Everglades is a vast freshwater peatland that has been impacted by the alterations of hydrological pattern and water quality which led to changes in plant species composition and biodiversity. In this study, carbon and nitrogen stable isotopes (δ13C and δ15N) in cattail (Typha domingensis) are evaluated as indicators of environmental changes in the Everglades wetlands along nutrient and hydrological gradients represented by reference sites with total phosphorus (TP) < 10 μg L−1, transition sites with TP ≥ 10 μg L−1 < 20 μg L−1 and impacted sites with TP ≥ 20 μg L−1 which differed in hydrology or habitats (marsh and canal). Results Cattail δ13C values decreased significantly from reference (–24.1‰), transition (–26.8‰) to the impacted sites (–28.2‰). In contrast, δ15N values increased significantly from reference (–5.2‰), transition (2.4‰) to the impacted site (5.9‰). In response to a poor hydrological condition, cattail in marsh area displayed 13C enrichment (–26.0‰) and 15N depletion (0.2‰). By contrast, cattail grown in the canal sites with favorable hydropattern displayed 13C depletion (–27.6‰) and 15N enrichment (5.9‰) from the canal sites with more favorable hydrological condition. Conclusions The different patterns for the changes in δ13C and δ15N in cattail suggested that increased nutrients led to increased stomatal conductance and 13C fractionation during carbon uptake and decreased 15N fractionation with increasing nitrogen demand while poor hydrological condition coupled with low nutrients led to reduced plant growth indicated by higher δ13C and lower δ15N values. Findings from this study suggested that δ13C in emerged macrophytes such as cattail can be used as an indicator for environmental stress while δ15N is a robust indicator for wetland eutrophication.
... Rapid growth in spring is fueled by stored carbohydrates (see rhizomes, Fig. 2c). Typha tends to be more responsive to environmental change than competitors, making it more adaptable to disturbed environments (Newman et al. 1996;Li et al. 2010;Webb and Zhang 2013). Typha also displays rapid nutrient uptake in nutrient-rich environments (Newman et al. 1996;Miao and Sklar 1998;Cicek et al. 2006). ...
... Typha tends to be more responsive to environmental change than competitors, making it more adaptable to disturbed environments (Newman et al. 1996;Li et al. 2010;Webb and Zhang 2013). Typha also displays rapid nutrient uptake in nutrient-rich environments (Newman et al. 1996;Miao and Sklar 1998;Cicek et al. 2006). ...
... Sediment and water chemistry strongly influence Typha growth and survival. Typha is often outcompeted by other aquatic macrophytes in low-nutrient, oligotrophic conditions (Newman et al. 1996;Currie et al. 2014). Increased nitrogen (N) and phosphorus (P) concentrations in wetland waters due to fertilizer runoff from agricultural fields promote the growth of Typha, allowing it to proliferate aggressively in nutrientenriched freshwater wetlands and brackish salt marshes (Boyd and Hess 1970;Newman et al. 1996;Miao and Sklar 1998;Galatowitsch et al. 1999) (see Nutrients). ...
Typha is an iconic wetland plant found worldwide. Hybridization and anthropogenic disturbances have resulted in large increases in Typha abundance in wetland ecosystems throughout North America at a cost to native floral and faunal biodiversity. As demonstrated by three regional case studies, Typha is capable of rapidly colonizing habitats and forming monodominant vegetation stands due to traits such as robust size, rapid growth rate, and rhizomatic expansion. Increased nutrient inputs into wetlands and altered hydrologic regimes are among the principal anthropogenic drivers of Typha invasion. Typha is associated with a wide range of negative ecological impacts to wetland and agricultural systems, but also is linked with a variety of ecosystem services such as bioremediation and provisioning of biomass, as well as an assortment of traditional cultural uses. Numerous physical, chemical, and hydrologic control methods are used to manage invasive Typha, but results are inconsistent and multiple methods and repeated treatments often are required. While this review focuses on invasive Typha in North America, the literature cited comes from research on Typha and other invasive species from around the world. As such, many of the underlying concepts in this review are relevant to invasive species in other wetland ecosystems worldwide.
... The Everglades supports a variety of rare, threatened, and endangered species that have adapted to these low nutrient concentrations, as well as, other physio-chemical conditions (e.g., low dissolved oxygen[DO]levels) that are characteristic of the system (Davis and Ogden 1994;Lodge 1994), and whose survival depends on the original cycle of water and nutrients, particularly low levels of phosphorous (Gunderson and Loftus 1993). Historically, rainfall alone provided the primary source of nutrients into the Everglades (Newman et al. 1996). However, agricultural development and urbanization since the 1800s have not only claimed almost two-thirds of the natural Everglades (only about 6000 km 2 now exist in their natural form) but have also dramatically increased phosphorus levelsin the Everglades landscape. ...
... These changes in water quality and other environmental disturbances associated with agricultural development in the Everglades were first identified as early as 1938 (Snyder and Davidson 1994). Overall, alterations to the nutrient input of the Everglades have resulted in widespread changes to the ecology of the ecosystem, with dramatic declines in the size of wading bird populations (Frederick and Collopy 1989;) and the invasion of species that include the cattail (Typha sp.) and duckweed into native sawgrass and slough habitats (Doren et al. 2009a, b;Miao and Sklar 1998;Newman et al. 1996;Rader and Richardson 1994). Any viable solution to improve conditions in the Everglades needs to reduce phosphorous concentrations from EAA runoff and improve the region's hydroperiod and hydropattern (Gwin et al. 1999;Payne et al. 2000). ...
... The new drier environments, which expanded at the sake of wetlands, created new biomes that little resembled the pre-geoengineered landscape. Some wetlands 'reclaimed' (by dredge and drain practices) from the Everglades, but now residing in the urban sprawl zone, are still subject to flooding in spite of land drainage (e.g.,Finkl 2000;Finkl and Myers 1995, 1996). Subsequent encroachment by farming, as in the Kissimmee River Valley and by sugar cane plantations in Broward County (Everglades Agricultural Area, EAA), polluted waters through the use of fertilizers (e.g., nitrogen and phosphorus macroelements, microelements, and amendments) and pesticides. ...
The Florida Everglades, currently designated as a Wetland of International Importance (Ramsar Convention), an International Biosphere Reserve (UNESCO), and a World Heritage Site in Danger (UNESCO), was administered around the turn of twentieth century by federal and state ditch and drain policies to ‘reclaim’ the coastal wetlands for urban sprawl, agriculture, and flood control. Today, the so-called ‘river of grass’ is only about half of its original extent; the remaining oligotrophic wetlands have been compromised by an ingress of nutrient-rich polluted and contaminated waters from agriculture and urban development. Furthermore, the spread of invasive flora and fauna have further compromised these wetland environments. In attempts to repair some of the damage wreaked upon this unique subtropical coastal ecosystem, numerous programs have been implemented to produce the world’s most expensive reclamation effort that amounts to more than US$8 billion. Positionalities of special interest groups and hegemonial overthrusts by various governmental agencies have produced a bewildering array of projects that fail to address the real causes of degradation while treating only symptoms instead. Due to the lack of common sense approaches of the restoration that deal with causes rather than symptoms, such as further wetland alteration to naturalize surface flow patterns of water and the inability to hinder the introduction/spread of exotic alien species, the Florida Everglades has evolved into something quite different from pre-settlement conditions, with major doubts that the ecosystem can be put back together again.
... In Egypt, it spreads in water bodies such as lakes, ditches and marshy places (Täckholm 1974, Boulos 2005); and it is one of the major components of the vegetation stands along the shores of Lake Burullus close to the Deltaic Mediterranean coast (Shaltout and Al-Sodany 2008). Although T. domingensis is now attracting attention for their usefulness in various ecological fields such as the influence on greenhouse gas emissions from wetlands (Chanton et al. 1993), mitigation strategies (Dobberteen and Nickerson 1991), wetlands diversity restoration (Newman et al. 1996) and purification of polluted water (Hegazy et al. 2011;Eid et al. 2012a, b), it is sometimes considered an invasive weed (Newman et al. 1996), where the overgrowth of this species that dominates aquatic habitats is often viewed as a potential threat to shallow ecosystems; and therefore, control of dramatic expansion of this aquatic plant has attained attention (Marks et al. 1994). ...
... In Egypt, it spreads in water bodies such as lakes, ditches and marshy places (Täckholm 1974, Boulos 2005); and it is one of the major components of the vegetation stands along the shores of Lake Burullus close to the Deltaic Mediterranean coast (Shaltout and Al-Sodany 2008). Although T. domingensis is now attracting attention for their usefulness in various ecological fields such as the influence on greenhouse gas emissions from wetlands (Chanton et al. 1993), mitigation strategies (Dobberteen and Nickerson 1991), wetlands diversity restoration (Newman et al. 1996) and purification of polluted water (Hegazy et al. 2011;Eid et al. 2012a, b), it is sometimes considered an invasive weed (Newman et al. 1996), where the overgrowth of this species that dominates aquatic habitats is often viewed as a potential threat to shallow ecosystems; and therefore, control of dramatic expansion of this aquatic plant has attained attention (Marks et al. 1994). ...
... Many studies were carried out on T. domingensis such as nutrients and heavy metals cycling (Eid et al. 2012a, b), phytoremediation (Hegazy et al. 2011), productivity (Eid et al. 2012c), modeling the growth dynamics (Eid et al. 2012c), flooding stress (Chen et al. 2013), restoration (Newman et al. 1996), and distribution (Khedr 1996, Khedr andEl-Demerdash 1997). According to the authors' knowledge, so far no published studies have been carried out to identify potential physiological weaknesses in the growth of T. domingensis based on seasonal carbohydrates allocation patterns. ...
Seasonal carbohydrates allocation by Typha domingensis was evaluated to identify the potential physiological weaknesses in the growth cycle of this plant in Lake Burullus, Egypt. Monthly plant samples (February–October 2014) were separated into shoots, roots and rhizomes to evaluate the seasonal changes in water-soluble carbohydrates (WSC), starch and total non-structural carbohydrates (TNC) for each plant organ. The present study indicated that rhizomes are strong carbohydrates sink during the life cycle of T. domingensis. Starch represented the greatest part of the TNC pool, surpassing the concentration of WSC 1.8–4.3 times. The WSC, starch and TNC concentrations of T. domingensis below-ground organs (rhizomes and roots) were high at the beginning of the vegetative period (February); they reached their minima in March to support the shoots growth, then were followed by a gradual increase due to the translocation from shoots. The time when T. domingensis is expected to be most susceptible to a management technique is at the point in the seasonal cycle when the stored carbohydrates are at the lowest (in March).
... The shoot can exceed 2 m in height and may or may not develop an apical flowering spike [15]. Although sometimes considered an invasive weed [16,17], Typha species are now attracting attention for their usefulness in various ecological fields such as purification of polluted water [7,18,19,20,21], bank protection against boat wash [22], wetlands diversity restoration [16,23,24], mitigation strategies [25] and the influence of the vegetation on greenhouse gas emissions from wetlands [26,27]. According to the authors' knowledge, so far no studies have been carried out on the accumulation of heavy metals by two macrophytes T. elephantina and T. domingensis grown under arid habitats like that in Saudi Arabia. ...
... The shoot can exceed 2 m in height and may or may not develop an apical flowering spike [15]. Although sometimes considered an invasive weed [16,17], Typha species are now attracting attention for their usefulness in various ecological fields such as purification of polluted water [7,18,19,20,21], bank protection against boat wash [22], wetlands diversity restoration [16,23,24], mitigation strategies [25] and the influence of the vegetation on greenhouse gas emissions from wetlands [26,27]. According to the authors' knowledge, so far no studies have been carried out on the accumulation of heavy metals by two macrophytes T. elephantina and T. domingensis grown under arid habitats like that in Saudi Arabia. ...
The present study investigated the ability of two emergent macrophytes Typha elephantina and Typha domingensis for accumulation of six heavy metals in an arid habitat in Saudi Arabia. Plant samples (aboveground shoot and belowground root and rhizome) as well as sediment samples were collected and analyzed. Regarding the variation in sediment characters, PH, EC, Cu, Ni, Pb and Zn concentrations of the T. elephantina sites were significantly higher than those of the T. domingensis sites; while Fe and Mn concentrations of the T. domingensis sites were significantly higher than those of the T. elephantina sites. T. elephantina allocated approximately 57.8% of its total biomass to leaves, 5.9% to flowers, 7.0% to peduncles, 18.7% to rhizomes and 10.6% to roots. The total above-ground biomass was 2.4 times that of the total below-ground biomass. T. domingensis allocated approximately 61.3% of its total biomass to leaves, 8.6% to flowers, 11.3% to peduncles, 9.8% to rhizomes and 9.0% to roots. The total above-ground biomass was 4.3 times that of the total below-ground biomass. Significant variations in Mn was recorded between T. elephantina and T. domingensis, while significant variations in Fe, Ni and Pb were recorded between the different organs. All heavy metals concentrations were significantly higher in belowground organs as compared to other plant organs. The heavy metal contents of T. elephantina and T. domingensis organs differed significantly between different plant organs. All the investigated species were characterized by a bioaccumulation factor > 1.0 for all heavy metals. In the present study, the translocation factor varied among plant species, among organs and among heavy metals. Finally, T. elephantina and T. domingensis could be regarded as a good candidates as phytoremediator for mitigating heavy metals pollution.
... The shoot can exceed 2 m in height and may or may not develop an apical flowering spike [15]. Although sometimes considered an invasive weed [16,17], Typha species are now attracting attention for their usefulness in various ecological fields such as purification of polluted water [7,18,19,20,21], bank protection against boat wash [22], wetlands diversity restoration [16,23,24], mitigation strategies [25] and the influence of the vegetation on greenhouse gas emissions from wetlands [26,27]. According to the authors' knowledge, so far no studies have been carried out on the accumulation of heavy metals by two macrophytes T. elephantina and T. domingensis grown under arid habitats like that in Saudi Arabia. ...
... The shoot can exceed 2 m in height and may or may not develop an apical flowering spike [15]. Although sometimes considered an invasive weed [16,17], Typha species are now attracting attention for their usefulness in various ecological fields such as purification of polluted water [7,18,19,20,21], bank protection against boat wash [22], wetlands diversity restoration [16,23,24], mitigation strategies [25] and the influence of the vegetation on greenhouse gas emissions from wetlands [26,27]. According to the authors' knowledge, so far no studies have been carried out on the accumulation of heavy metals by two macrophytes T. elephantina and T. domingensis grown under arid habitats like that in Saudi Arabia. ...
The present study investigated the ability of two emergent macrophytes Typha elephantina and Typha domingensis for
accumulation of six heavy metals in an arid habitat in Saudi Arabia. Plant samples (aboveground shoot and belowground
root and rhizome) as well as sediment samples were collected and analyzed. Regarding the variation in sediment
characters, PH, EC, Cu, Ni, Pb and Zn concentrations of the T. elephantina sites were significantly higher than those of
the T. domingensis sites; while Fe and Mn concentrations of the T. domingensis sites were significantly higher than those
of the T. elephantina sites. T. elephantina allocated approximately 57.8% of its total biomass to leaves, 5.9% to flowers,
7.0% to peduncles, 18.7% to rhizomes and 10.6% to roots. The total above‐ground biomass was 2.4 times that of the
total below‐ground biomass. T. domingensis allocated approximately 61.3% of its total biomass to leaves, 8.6% to
flowers, 11.3% to peduncles, 9.8% to rhizomes and 9.0% to roots. The total above‐ground biomass was 4.3 times that
of the total below‐ground biomass. Significant variations in Mn was recorded between T. elephantina and T. domingensis,
while significant variations in Fe, Ni and Pb were recorded between the different organs. All heavy metals
concentrations were significantly higher in belowground organs as compared to other plant organs. The heavy metal
contents of T. elephantina and T. domingensis organs differed significantly between different plant organs. All the
investigated species were characterized by a bioaccumulation factor > 1.0 for all heavy metals. In the present study, the
translocation factor varied among plant species, among organs and among heavy metals. Finally, T. elephantina and T.
domingensis could be regarded as a good candidates as phytoremediator for mitigating heavy metals pollution.
... The shoot can exceed 2 m in height and may or may not develop an apical flowering spike [15]. Although sometimes considered an invasive weed [16,17], Typha species are now attracting attention for their usefulness in various ecological fields such as purification of polluted water [7,18,19,20,21], bank protection against boat wash [22], wetlands diversity restoration [16,23,24], mitigation strategies [25] and the influence of the vegetation on greenhouse gas emissions from wetlands [26,27]. According to the authors' knowledge, so far no studies have been carried out on the accumulation of heavy metals by two macrophytes T. elephantina and T. domingensis grown under arid habitats like that in Saudi Arabia. ...
... The shoot can exceed 2 m in height and may or may not develop an apical flowering spike [15]. Although sometimes considered an invasive weed [16,17], Typha species are now attracting attention for their usefulness in various ecological fields such as purification of polluted water [7,18,19,20,21], bank protection against boat wash [22], wetlands diversity restoration [16,23,24], mitigation strategies [25] and the influence of the vegetation on greenhouse gas emissions from wetlands [26,27]. According to the authors' knowledge, so far no studies have been carried out on the accumulation of heavy metals by two macrophytes T. elephantina and T. domingensis grown under arid habitats like that in Saudi Arabia. ...
The present study investigated the ability of two emergent macrophytes Typha elephantina and Typha domingensis for accumulation of six heavy metals in an arid habitat in Saudi Arabia. Plant samples (aboveground shoot and belowground root and rhizome) as well as sediment samples were collected and analyzed. Regarding the variation in sediment characters, PH, EC, Cu, Ni, Pb and Zn concentrations of the T. elephantina sites were significantly higher than those of the T. domingensis sites; while Fe and Mn concentrations of the T. domingensis sites were significantly higher than those of the T. elephantina sites. T. elephantina allocated approximately 57.8% of its total biomass to leaves, 5.9% to flowers, 7.0% to peduncles, 18.7% to rhizomes and 10.6% to roots. The total above‐ground biomass was 2.4 times that of the total below‐ground biomass. T. domingensis allocated approximately 61.3% of its total biomass to leaves, 8.6% to flowers, 11.3% to peduncles, 9.8% to rhizomes and 9.0% to roots. The total above‐ground biomass was 4.3 times that of the total below‐ground biomass. Significant variations in Mn was recorded between T. elephantina and T. domingensis, while significant variations in Fe, Ni and Pb were recorded between the different organs. All heavy metals concentrations were significantly higher in belowground organs as compared to other plant organs. The heavy metal contents of T. elephantina and T. domingensis organs differed significantly between different plant organs. All the investigated species were characterized by a bioaccumulation factor > 1.0 for all heavy metals.
... T. domingensis est une hélophyte particulièrement adaptée à l'inondation du sol. Ses performances la placent devant la plupart des autres espèces du genre (Grace, 1988(Grace, , 1989, et devant d'autres hélophytes comme l'Herbe coupante Cladium jamaicense (Newman et al., 1996 ;Chabbi et al., 2000). La grande aptitude de cette espèce à l'inondation du sol se manifeste notamment par un potentiel de croissance pratiquement inchangé pour des niveaux de submersion atteignant jusqu'à 1,3 m durant plusieurs semaines (Grace, 1989 ;Chen et al., 2013). ...
... A la différence d'autres hélophytes, comme Cladium jamaicense ou Eleocharis interstincta, adaptés aux environnements oligotrophes, T. domingensis manifeste une croissance beaucoup plus vigoureuse en présence d'apports nutritifs azotés et, surtout, phosphorés (Davis, 1991 ;Newman et al., 1996 ;Miao et Sklar, 1997 ;Lorenzen et al., 2001 ;Escutia--Lara et al., 2009 ;Gophen, 2010 ;Macek et al., 2010 ;Rodriguez--Santos et al., 2015). Il a été montré que la disponibilité du phosphore dans le sol est diminuée en milieu réducteur (DeLaune et al., 1999). ...
... In these high-P habitats, benthic algal mats dominated by diatom and cyanobacteria foundation species cannot grow because of shading [94] or allelopathy [95]. Similar to other species growing in infertile soils [96], sawgrass allocates the little P available to its leaves, roots, and rhizomes whilst storing more nutrients in shoot bases [50,97]. In the 1970s and 1980s, an increase in soil and water P concentrations [98] triggered the replacement of sawgrass by cattail-an autochthonous sedge [99]-which is more competitive in high-nutrient environments [95]. ...
... Conservation actions need to take into account that biological communities depending on foundation species may be particularly sensitive to ecosystem shifts between alternative stable states [209]. For example, because of long-term nutrient enrichment (a press driver) caused by decades of agricultural fertilization [94,97,[210][211][212][213], cattail has expanded replacing thousands of hectares of sawgrass marshes and aquatic slough areas in the central Everglades [50], in marshes in northern Belize [47], and wetlands in Guadeloupe (Lesser Antilles [62]). Similarly, decades of elevated atmospheric nitrogen deposition in northern temperate wetlands may have induced a transition towards ecosystem states that will eventually be dominated by currently invading vascular plants such as Molinia and Betula spp. ...
Foundation species provide habitat to other organisms and enhance ecosystem functions, such as nutrient cycling, carbon storage and sequestration, and erosion control. We focus on freshwater wetlands because these ecosystems are often characterized by foundation species; eutrophication and other environmental changes may cause the loss of some of these species, thus severely damaging wetland ecosystems. To better understand how wetland primary producer foundation species support other species and ecosystem functions across environmental gradients, we reviewed ~150 studies in subtropical, boreal, and temperate freshwater wetlands. We look at how the relative dominance of conspicuous and well-documented species (i.e., sawgrass, benthic
diatoms and cyanobacteria, Sphagnum mosses, and bald cypress) and the foundational roles they play interact with hydrology, nutrient availability, and exposure to fire and salinity in representative wetlands. Based on the evidence analyzed, we argue that the foundation species concept should be more broadly applied to include organisms that regulate ecosystems at different spatial scales, notably the microscopic benthic algae that critically support associated communities and mediate freshwater wetlands’ ecosystem functioning. We give recommendations on how further research efforts can be prioritized to best inform the conservation of foundation species and of the freshwater
wetlands they support.
... Herbaceous plants (C. angustifolia) recover more quickly after burning relative to woody plants, especially during the growing season will absorb large amounts of nutrient elements from the soil for growth (Newman et al., 1996), which caused a large amount of P transfer from the soil to the plant. ...
Fire is an important disturbance of wetland P reservoirs by changing the distribution of P in soils and plants. However, the effects of various fire regimes on the distribution of P in wetlands are not known. In a three-year burn experiment, we evaluated the effects of three burn factors on the P distribution of plants (stem, leaf, and litter) and soils (upper and lowerlayer soil) in the freshwater wetlands of China's Sanjiang Plain. We discovered that when burn frequency increased, soil P content and total plant biomass P also increased. Soil P content peaked at a high of 2198.0 ± 559.0 mg kg − 1 after three burns. Three burns increased C. angustifolia biomass and therefore increased total plant biomass P. However, the increase in time after burning caused stem and leaf P content and litter necromass density P to decrease, suggesting a steady transfer of plant P to the soil. Furthermore , the stem biomass P density in September after the three burns was higher in spring burns than in autumn burns (1231.0 ± 129.0 mg m − 2 after spring burns compared to 542.0 ± 176.0 mg m − 2 after autumn burns). The transfer of litter P to the soil was hindered by spring burns, which conserved more P in the litter than autumn burns, which was the opposite of what was found for litter necromass P. Compared to spring burns, frequent autumn burns will hasten the transfer of plant P to the soil, preserving more P in the soil. Thus, conducting once-a-year prescribed burning in the autumn will be an important tool for improving P cycling in freshwater wetlands compared to spring.
... To this end, well-documented environmental proxies were used (Table 1), whose data were extracted from previous studies at Montcortès (Trapote, 2019). Specifically, the following proxies were chosen: the abundances of Typha pollen and Pediastrum cells were chosen as indicators of changes in nutrient conditions (Jankovská and Komárek, 2000;Miao and Sklar, 1998;Newman et al., 1996), distinct pollen grains for crops and ruderal herbs, Cannabis pollen for hemp retting (Rull and Vegas-Vilarrúbia, 2014), bestrepresented charcoal particles representing regional fires (Whitlock and Larsen, 2001), Glomus fungus spores for soil erosion (Kołaczek et al., 2022;van Geel et al., 1989), and coprophilous fungi such as Sporormiella for the presence of livestock (Lee et al., 2022;Raczka et al., 2016). The temporal resolutions of these selected records and the diatom records of the present study are coincident, as both studies obtained their samples from the same sediment core and at the same depths. ...
In the Mediterranean region, annual mean air temperature will continue to increase during the 21st century, while seasonal precipitation is expected to decrease and extreme events to be more frequent. Human-induced climate change will severely impact aquatic ecosystems. A subdecadal stratigraphic diatom record of Lake Montcortès (central Pyrenees) was investigated, focusing on the potential responses of diatoms to anthropogenic warming and catchment alteration. The study includes the end of the Little Ice Age (LIA), the transition to the industrial and postindustrial eras, and the recent global warming and its current acceleration. Sediment samples were treated and diatoms taxonomically identified. Relationships between diatom taxa abundances and climatic (temperature and precipitation) and environmental (land use, soil erosion, and eutrophication) variables were investigated using multivariate statistical methods. The results indicate that, from ca. 1716 to 1971 CE, the diatom community was dominated by Cyclotella cyclopuncta and showed small perturbations, despite the pressure of important stressors such as strong cooling episodes, droughts and an intense use of the lake for hemp retting during the 18th and 19th centuries. However, during the 20th century, other centric species gained relevance, and from the 1970s on, Cyclotella ocellata competed with C. cyclopuncta for dominance. These changes coincided with pulse-like disturbances in the form of extreme rainfall events along with the gradual 20th century increase in global temperature. These perturbations affected the planktonic diatom community and led to instability dynamics. The benthic diatom community did not reflect any comparable shifts under the effect of the same climatic and environmental variables. Because heavy rainfall episodes are likely to intensify with current climate change in the Mediterranean region, their importance as stressors of planktonic primary producers should be taken into account as potential disrupters of biogeochemical cycles and trophic networks of lakes and ponds.
... Typha domingensis is one of the main components of vegetation that stands along the shores of Lake Burullus close to the Deltaic Mediterranean coast (Shaltout and Al-Sodany 2008). Typha domingensis is used in constructed wetlands for the enhancement of water quality (Abdel-Ghani et al. 2009) due to its high growth rate and great capacity for heavy metal accumulation (Newman et al. 1996;Lorenzen et al. 2001). iii Potamogeton pectinatus is a submerged perennial aquatic macrophyte (Boulos 2005) with a parvopotamid growth form (Hogeweg and Brenkert 1969). ...
Nowadays, the importance of using macrophytes in accumulation of heavy metals has gained great concerns. So, this study aimed at extracting the land use/cover types of three indices and surface temperatures in the habitats inside 100 m buffers from recent satellite images around three highly economic macrophytes namely; Phragmites australis, Typha domingensis and Potamogeton pectinatus species. In addition to land surface temperature (LST), three important indices expressing the land cover of habitats namely; normalized different vegetation index (NDVI), normalized different water index (NDWI), and normalized different moisture index (NDMI) were extracted to find out there influence on the efficiency of macrophytes in the accumulation of these metal ions; Fe, Cu, Zn, Cd and Pb. The Polynomial regression models were calculated to predict the accumulation factors of plants within the remotely sensed indices and LST. Results showed different accumulation values for individual or more metals in the below-ground and above-ground parts of macrophytes within different habitats. This study considers as an innovative approach using remote sensing technique and satellite images for the selecting of species that can accumulate more metals within different habitats. The obtained results will be useful for the optimal management of these macrophytes in Lake Burullus, a Ramsar site.
... This significant correlation pattern can be found at charcoal-Poaceae, charcoal-Cruciferae and charcoal-Typha at lag0 (P < 0.001), indicating an rapid positive response to fire events. Notably, such a good correlation (P < 0.001) was found with Poaceae-Typha, implying Typha was possibly linked to agriculture with nutrient inputs as recent studies indicated (Fig. 6) (Newman et al., 1996;Bansal et al., 2019). ...
Human perturbation and its impact on vegetation and plant diversity during the Holocene have caused serious concerns for the biogeological and geoarchaeological communities. As a centre of origin of rice agriculture, the lower Yangtze region (LYR) has a long history of human occupation over most of the Holocene. However, early anthropogenic impacts on the ecosystem of the region remain elusive. Here we present a multidisciplinary study including pollen and charcoal analysis on three different sediment cores (TJA, YJ1503 and PW) along a gradient of human interference to disentangle human and climatic influences on vegetation in the coastal area of the LYR. The results show that rice farming which developed after an environmental transition from salt marsh to freshwater wetland was mainly assisted by fire, particularly slash-and-burn practices by the Neolithic people between 7 and 4 kyr BP. Both the vegetation composition and plant diversity of the mixed forests of the LYR responded to these early human perturbations with a threshold effect. However, whereas plant diversity rapidly recovered when human activity ceased/weakened, the vegetation composition showed differences from the pre-fire condition, indicating a lasting effect. We propose that the varied post-fire recovery strategies of different species, e.g. Quercus evergreen comp. versus Pinus massonania, would account for this discrepancy.
... From the results it was therefore inferred that above 15 °C temperature, a HRT 8-day is satisfactory, whereas below 15 °C temperature, greater hydraulic retention time like HRT 14-day or HRT 20-day was necessary. Newman et al. (1996) and Grace (1989) reported that the dominance of Typha sp. is supported by shallow water depths (i.e., 0.2-0.3 m) and nutrient enrichment in water bodies. ...
Eutrophication is an excessive plant-growth process that is one of the serious water pollution problems caused by accelerated nutrient enrichment through runoffs carrying fertilizers, human wastes, etc., which leads to loss of dissolved oxygen and significant deterioration of the water quality and ultimately affecting the aquatic life. Various conventional mechanisms had been introduced to treat nutrient enrichment in water, however, these methods involve high capital for advanced treatments along with the adverse effect of treated chemicals on the aquatic ecosystem. Hence, phytoremediation has emerged as an alternative, eco-friendly, cost-effective technology for treating wastewater compared to conventional technologies. Plants-based in situ solar dependent remediation methods and microbiological techniques are applied in phytoremediation process to reduce the pollutants in natural conditions. The capacity of various aquatic macrophytes for removing nutrients (total Nitrogen and total Phosphorus) from wastewater has been highlighted in the present review paper. Aquatic macrophytic species such as Eichhornia, Pistia, and Typha have been reported as phytoremediators which are highly efficient in nutrient removal (>90%) from the contaminated water bodies. Therefore, the primary focus of this review article is to assess the current state of phytoremediation as an alternative and advanced technology for the remediation and management of nutrient contaminated water and to highlight the nutrient removal capacity of the aquatic plants.KeywordsPhytoremediationEutrophicationTotal nitrogenTotal phosphorusNutrientsWastewater
... If high water conditions also carry nutrients, the competitive advantage of high nutrient uptake rates may allow Typha to maintain and expand its dominance (Miao and Sklar 1997;Bansal et al. 2019). Due to its relatively fast growth rates and ability to take up nutrients rapidly, Typha thrives in areas of high nutrient input (i.e., nitrogen and phosphorous) (Newman et al. 1996;Miao and Sklar 1997;Mack et al. 2000). Woo and Zedler (2002) conducted nitrogen-and phosphorous-addition experiments with T. × glauca and native sedge-meadow species to determine if these additions accelerated the expansion of T. × glauca into wet meadow zones. ...
Loss of Great Lakes wetlands due to changes in land use, hydrology, nutrient inputs, and invasive species led to the need for studies involving physical factors that influence growth of invasive cattails (Typha). Thus, in 18 Lake Ontario coastal wetlands, we sampled vegetation along stratified random transects and collected water samples for total phosphorus (TP) analyses. We used GIS to determine watershed area, percent land use as croplands, and length of lotic surface waters entering wetlands. A greenhouse growth experiment with a full factorial random block design was used to investigate the effects of variable hydroperiod and phosphorus concentrations on T. × glauca biomass changes. Correlation analyses of wetland data revealed that TP in field studies was related to percent croplands but not lotic length; mean percent Typha was not related to TP. In the growth experiment, above- and below-ground biomass increased significantly for simple main effects of hydroperiod and phosphorus concentrations. Multiple pairwise interaction comparisons between hydrology and nutrient treatments showed that effects of phosphorus concentration were present only at longer hydroperiods. Lack of correlation between Typha and phosphorus concentrations in the field was likely due to the overwhelming effect of water-level regulation on Lake Ontario. The greenhouse study demonstrated that increasing concentrations of phosphorus positively influenced cattail growth in a controlled setting. Although phosphorus positively influenced growth, hydrologic regime had the greatest influence on cattail growth, with increased biomass as hydroperiod increased. More natural hydrology and management of phosphorus inputs may help limit spread of Typha.
... It is also possible that one of the primary services of coastal wetlands-their ability to filter nutrients and pollutants entering the lakes-may be diminished if wetland extent or vegetation structure is reduced. Increased phosphorus levels in the Florida Everglades have resulted in the replacement of native sawgrass (Cladium) with cattail (Typha), thereby disrupting and negatively impacting ecosystem function [119]. Anthropogenic attempts at management for high and low water levels in the Great Lakes, through the installation of seawalls and dredging activities [120], may further diminish connectivity to groundwater. ...
Groundwater historically has been a critical but understudied, underfunded, and underappreciated natural resource, although recent challenges associated with both groundwater quantity and quality have raised its profile. This is particularly true in the Laurentian Great Lakes (LGL) region, where the rich abundance of surface water results in the perception of an unlimited water supply but limited attention on groundwater resources. As a consequence, groundwater management recommendations in the LGL have been severely constrained by our lack of information. To address this information gap, a virtual summit was held in June 2021 that included invited participants from local, state, and federal government entities, universities, non-governmental organizations, and private firms in the region. Both technical (e.g., hydrologists, geologists, ecologists) and policy experts were included, and participants were assigned to an agricultural, urban, or coastal wetland breakout group in advance, based on their expertise. The overall goals of this groundwater summit were fourfold: (1) inventory the key (grand) challenges facing groundwater in Michigan; (2) identify the knowledge gaps and scientific needs, as well as policy recommendations, associated with these challenges; (3) construct a set of conceptual models that elucidate these challenges; and (4) develop a list of (tractable) next steps that can be taken to address these challenges. Absent this type of information, the sustainability of this critical resource is imperiled.
... under increased flood and nutrient conditions have led to Typha spp. dominance in many wetland ecosystems (Newman, Grace, and Koebel 1996;Todd et al. 2010). ...
The following synthesizes studies investigating plant and soil responses to increased inundation in order to support ecosystem restoration efforts related to the alteration of natural wetland hydrodynamics. Specific topics include hydrologic regimes, soil response to inundation, and implications for vegetation communities exposed to increased water depths. Results highlight the important interactions between water, soils, and vegetation that determine the trajectory and fate of wetland ecosystems, including the development of feedback loops related to marsh degradation and subsidence. This report then discusses the knowledge gaps related to implications of inundation depth, timing, and duration within an ecosystem restoration context, identifying opportunities for future research while providing source materials for practitioners developing restoration projects.
... Although East End also had undulating bathymetry and only the levees were transplanted with S. acutus, Typha spp. spread rapidly by outcompeting other species under high P conditions because they are hyper-accumulators [87,88]. High P conditions (>500 μg g -1 ) have been shown to result in highly productive, but low diversity plant communities, which benefits C uptake, but counteract biodiversity targets of restoration [4,89]. ...
Inundated wetlands can potentially sequester substantial amounts of soil carbon (C) over the long-term because of slow decomposition and high primary productivity, particularly in climates with long growing seasons. Restoring such wetlands may provide one of several effective negative emission technologies to remove atmospheric CO 2 and mitigate climate change. However, there remains considerable uncertainty whether these heterogeneous ecotones are consistent net C sinks and to what degree restoration and management methods affect C sequestration. Since wetland C dynamics are largely driven by climate, it is difficult to draw comparisons across regions. With many restored wetlands having different functional outcomes, we need to better understand the importance of site-specific conditions and how they change over time. We report on 21 site-years of C fluxes using eddy covariance measurements from five restored fresh to brackish wetlands in a Mediterranean climate. The wetlands ranged from 3 to 23 years after restoration and showed that several factors related to restoration methods and site conditions altered the magnitude of C sequestration by affecting vegetation cover and structure. Vegetation established within two years of re-flooding but followed different trajectories depending on design aspects, such as bathymetry-determined water levels, planting methods, and soil nutrients. A minimum of 55% vegetation cover was needed to become a net C sink, which most wetlands achieved once vegetation was established. Established wetlands had a high C sequestration efficiency (i.e. the ratio of net to gross ecosystem productivity) comparable to upland ecosystems but varied between years undergoing boom-bust growth cycles and C uptake strength was susceptible to disturbance events. We highlight the large C sequestration potential of productive inundated marshes, aided by restoration design and management targeted to maximise vegetation extent and minimise disturbance. These findings have important implications for wetland restoration, policy, and management practitioners.
... Monthly variations in wax synthesis might introduce variations in our measured proxies. Although the wet season (May to November) is the primary growing season for most of plant species (Newman et al., 1996;Ewe and Sternberg, 2003), the freshwater marsh ecosystems of the Everglades are oligotrophic, subtropical wetlands with a year-round growing season (Malone et al., 2013). Leaf wax n-alkane d 2 H values could mainly reflect leaf water d 2 H values at the time of leaf formation (Sachse et al., 2010;Tipple et al., 2013;Freimuth et al., 2017), or the leaf wax n-alkane d 2 H values could vary temporally, which has been observed in four riparian plant species (Oakes and Hren, 2016;Huang et al., 2018). ...
Reconstructing past responses of coastal wetlands to climate change contextualizes ongoing and future developments in these globally important ecosystems. The molecular distributions and stable isotope ratios (δ²H and δ¹³C) of sedimentary plant wax n-alkanes are frequently used to infer past vegetation and hydroclimate changes in wetland systems. However, there is limited modern information available about these compounds in subtropical wetlands. Here we analyzed mature leaves from 30 typical plant species and roots from 6 plant species collected in the Florida Everglades, including tree island plants, freshwater wetland plants, mangroves, and seagrass. The n-alkane abundance (2 to 884 µg/g dry weight), percent of aquatic plants ratio (Paq, 0 to 1), average chain length (ACL23-33, 24.0 to 30.7), concentration weighted average (CWA) δ²H (-231 to -78‰) and δ¹³C values (-38.9 to -14.4‰) spanned wide ranges with plant growth habit. Significant differences in n-alkane abundances, Paq, ACL23-33, CWA δ²H and δ¹³C values were found to exist between the leaves and roots of some emergent aquatic plants. Simple mass balance calculations of wetland aquatic plants suggest that long chain n-alkanes (e.g., C29n-alkanes) are predominantly derived from leaves rather than roots in wetland surface sediments/soils. However, the contribution from mid-chain n-alkanes (e.g., C23n-alkane) from roots may be equal to or greater than those from leaves. This implies that the differences in the isotopic compositions between root and leaf derived material need to be taken into account when interpreting down core changes in mid-chain n-alkane δ²H and d¹³C values, which may be derived from variable contributions from leaves and roots rather than a change in hydroclimate or vegetation. Considering the large variation in both n-alkane distribution proxies and isotopic composition, no single molecular index or stable isotope ratio can capture multivariate changes of wetland ecosystems in the past. Nevertheless, principal component analysis shows promising potential to resolve different plant functional types. Paleo-reconstruction of subtropical aquatic ecosystems using n-alkanes will be most useful if the full molecular and isotopic distribution information of plant waxes are used.
... Interestingly, these adaptions can signify that low levels of flooding (−10 cm) are stressful for this species (unpublished results). Meanwhile, C. jamaicense is reportedly more sensitive to flooding (Newman, Grace, & Koebel, 1996) and to water with high phosphorus concentrations. For these reasons, it was displaced by T. domingensis in the Everglades as this environment transformed from oligotrophic to eutrophic (Davis, 1991). ...
Coastal zones are characterized by the interactions between continents and oceans and, therefore, between fresh and salt surface and groundwater. The wetlands of coastal zones represent transitional ecosystems that are affected by these conditions, although little is known about the hydrogeochemistry of wetlands, especially coastal wetlands. In the present study, the hydrogeochemical characterization of coastal freshwater herbaceous wetlands in the Ciénaga del Fuerte Protected Natural Area in Veracruz, Mexico, in the American tropics was carried out per plant community. Four herbaceous wetlands (alligator flag, saw grass, cattail and floodplain pasture) were monitored to understand the origin of the water feeding these ecosystems, the hydrogeochemical composition of groundwater, and the relationship between the groundwater and ecology of these ecosystems during dry and rainy seasons. The results indicate that Ciénaga del Fuerte is located in a regional discharge area but also receives local recharge, so it is fed by both regional and local flows. The chemical composition varied temporally and spatially, creating unique conditions that determined the habitat occupied by the hydrophytic vegetation. The spatio temporal behavior of groundwater is one factor that, along with the hydroperiod, determines wetland dynamics and affects wetland biota (ecohydrogeochemistry). Generalist plant communities established in zones of local recharge, whereas other more specialized and/or plastic communities inhabited zones receiving regional flows with greater ion concentrations. This information forms the basis for establishing an appropriate scale (municipal, state, or larger regions) for the sustainable management of goods and services provided by the wetlands.
... Furthermore, unlike nitrogen, P builds in soils once it exceeds the ability of the biota to sequester it where it can become remineralized and drive additional eutrophication through time (Qualls and Richardson 2008). Finally, through time, even low-level P loading can drive the dissolution of periphyton mats, modify consumer dynamics (Gaiser et al. 2005), and drive regime shifts in algal (Pan et al. 2000) and vegetation communities (Davis and Ogden 1994;Newman et al. 1996;Daoust and Childers 2004), with implications for OC dynamics and beyond. ...
Increasing rates of sea-level rise (SLR) threaten to submerge coastal wetlands unless they increase soil elevation at similar pace, often by storing soil organic carbon (OC). Coastal wetlands face increasing salinity, marine-derived nutrients, and inundation depths from increasing rates of SLR. To quantify the effects of SLR on soil OC stocks and fluxes and elevation change, we conducted two mesocosm experiments using the foundation species sawgrass (Cladium jamaicense) and organic soils from freshwater and brackish Florida Everglades marshes for 1 year. In freshwater mesocosms, we compared ambient and elevated salinity (fresh, 9 ppt) and phosphorus (ambient, + 1 g P m−2 year−1) treatments with a 2 × 2 factorial design. Salinity addition reduced root biomass (48%), driving 2.8 ± 0.3 cm year−1 of elevation loss, while soil elevation was maintained in freshwater conditions. Added P increased root productivity (134%) but also increased breakdown rates (k) of roots (31%) and leaves (42%) with no effect on root biomass or soil elevation. In brackish mesocosms, we compared ambient and elevated salinity (10, 19 ppt) and inundated and exposed conditions (water level 5-cm below and 4-cm above soil). Elevated salinity decreased root productivity (70%) and root biomass (37%) and increased k in litter (33%) and surface roots (11%), whereas inundation decreased subsurface root k (10%). All brackish marshes lost elevation at similar rates (0.6 ± 0.2 cm year−1). In conclusion, saltwater intrusion in freshwater and brackish wetlands may reduce net OC storage and increase vulnerability to SLR despite inundation or marine P supplies.
... The evidence on saltwater causing P desorption from limestone is clear (Price et al. 2006, Flower et al. 2017; however, the magnitude of desorption is likely to be variable depending on initial conditions and the rate of saltwater intrusion. There are a myriad of studies within the Everglades that examine how increased P loading affects ecosystem functioning (e.g., Newman et al. 1996, Noe et al. 2003, Gaiser et al. 2005. Because any P concentration over 5 ppb can offset P limitation to organisms in the Everglades (Noe et al. 2003), we chose to target our P load at~1 g PÁm À2 Áyr À1 , which is similar to the loading rate of other wetland P enrichment experiments and is likely to elicit a response from the biota (Craft et al. 1995, Daoust and Childers 2004, Gaiser et al. 2005, Macek and Rejmankova 2007. ...
Saltwater intrusion and salinization of coastal wetlands around the world are becoming a pressing issue due to sea level rise. Here, we assessed how a freshwater coastal wetland ecosystem responds to saltwater intrusion. In wetland mesocosms, we continuously exposed Cladium jamaicense Crantz (sawgrass) plants and their peat soil collected from a freshwater marsh to two factors associated with saltwater intrusion in karstic ecosystems: elevated loading of salinity and phosphorus (P) inputs. We took repeated measures using a 2 × 2 factorial experimental design (n = 6) with treatments composed of elevated salinity (~9 ppt), P loading (14.66 μmol P/d), or a combination of both. We measured changes in water physicochemistry, ecosystem productivity, and plant biomass change over two years to assess monthly and two‐year responses to saltwater intrusion. In the short‐term, plants exhibited positive growth responses with simulated saltwater intrusion (salinity + P), driven by increased P availability. Despite relatively high salinity levels for a freshwater marsh (~9 ppt), gross ecosystem productivity (GEP), net ecosystem productivity (NEP), and aboveground biomass were significantly higher in the elevated salinity + P treated monoliths compared to the freshwater controls. Salinity stress became evident after extended exposure. Although still higher than freshwater controls, GEP and NEP were significantly lower in the elevated salinity + P treatment than the +P treatment after two years. However, elevated salinity decreased live root biomass regardless of whether P was added. Our results suggest that saltwater intrusion into karstic freshwater wetlands may initially act as a subsidy by stimulating aboveground primary productivity of marsh plants. However, chronic exposure to elevated salinity results in plant stress, negatively impacting belowground peat soil structure and stability through a reduction in plant roots.
... In particular, Phragmites australis is the most widely used in Europe and Asia; Typha latifolia in North America; Cyperus papyrus and Scirpus validus in Oceania; whereas, P. australis, and Typha domingensis are the predominat species in South America [VYMAZAL 2011]. Actually, Thypa sp., has deserved a lot of attention for its usefulness in several ecological aspects, such as improving water quality in treatment systems [COVENEY et al. 2002;GOMES et al. 2013;HEGAZY et al. 2011;SCHRODER et al. 2003], restoring the diversity in wetlands [BOERS et al. 2007;NEWMAN et al. 1996], influencing greenhouse gas emissions in wetlands [CHANTON et al. 1993;GROSS et al. 1993] and nutrients recycling [SHARMA et al. 2006]. ...
The treatment of pool water, whether for recreational or sporting purposes, by phytoremediation is widely applied. This work evaluates two artificial vertical flow wetlands, one on a real scale and the other on a laboratory scale, which have been planted with Typha domingensis, for the treatment of pool water in the climatic conditions of the city of Santiago de Cuba. When the hydraulic load applied to the real scale wetland was less than 0.25 m 3 •m-2 •d-1 , the levels of organic and microbiological contamination in the pool were below the maximum limits allowed by Cuban standards. At a laboratory scale, the presence of vegetation favoured the elimination of nitrogen compounds (nitrates and ammonium) and organic materials (BOD and COD). This behaviour is explained by the presence of processes of assimilation of organic compounds, or by the action of microorganisms associated with the rhizome of plants, which establish a symbiotic mechanism favourable to phytodepuration. The minimum concentration of ammonium obtained in outflow from the laboratory-scale reactor without vegetation reached a value of 2.15 mg•m-3 , which is within the limits allowed by the sanitary regulations.
... Increases in Cyperaceae and Typha have been related to fluctuations in water levels but also with water nutrient enrichment. Typha species thrives in areas of high nutrient input (i.e., nitrogen and phosphorous) mainly because of their fast growth rates and ability to take up nutrients rapidly (Newman et al., 1996;Miao and Sklar, 1998). The notable increase in Pediastrum 1680 to 1850 CE and Tetraedon peak that coincided with hemp maxima might also be related with eutrophication processes as it has been observed in other similar lakes with hemp retting . ...
A high-resolution (average 6 years/sampling interval) palaeoenvironmental reconstruction using pollen, charcoal
and non-pollen palynomorphswas carried out on annually laminated sediments of LakeMontcortès (southern
Pyrenean flank). The results were combined with historical data to better understand landscape evolution
and human interaction during the last 500 years. Our results show that human activities (cropping, livestock
breeding and hemp cultivation and retting) have been the most important factors responsible for vegetation
changes with highest intensity between 1530 and 1900 CE. By means of a sub-decadal study we have been
able to evaluate short-lasting events at local and regional scales related to climate (heavy rainfall events and,
high-land forest fluctuations) or to historical and well-dated and documented socio-economic events (i.e., crop
promotions (hemp) or land abandonment-population emigration). The temporal extent (400 years) and continuity
of Cannabis pollen peak have been confirmed, and new evidence of water quality changes, likely as a consequence
of hempretting practices between the mid-17th to late 19th century, are provided. This is the first highresolution
palaeoenvironmental study carried out in a varved lake on the Iberian Peninsula so far. With these data
we hope to contribute to filling the gap in high-resolution palaeoenvironmental data.
... However, "hydroperiod" does not inform the ways all species interact with the environment. The relationship between hydroperiod and ecological dynamics may differ for animals (Snodgrass et al. 2000) and plants (Newman et al. 1996). This makes it difficult to gain ecological insight into the constraints on individuals or populations if they all respond differently to hydroperiod. ...
In dynamic environments, resource availability may change by several orders of magnitude , over hours to months, but the duration of resource availability is not often included as a characteristic attribute of resources even though temporal resource dynamics might limit patterns of use. In our study of wading birds foraging in intertidal areas, tides cause large changes in the areal extent of shallow-water foraging habitat (i.e., the resource), but tides also constrain the duration of availability, which is often overlooked. We hypothesized that temporal constraints on habitat availability from tides would be reflected in patterns of habitat use by foraging birds. We estimated the time-integrated habitat availability and compared it to traditional habitat attributes (seagrass cover, substrate type, instantaneous water depth, and proximity to mangrove islands or deep water) that have strong eviden-tial support for influencing patterns of use. To evaluate our hypotheses, we quantified habitat attributes at intertidal areas in the Florida Keys, USA, where wading birds were observed foraging (Little Blue Heron, Egretta caerulea: N = 183; Great White Heron, Ardea herodias occidentalis: N = 162). We tested for nonrandom use by sampling habitat attributes at two spatial scales around the observed feeding locations and we analyzed the data using a conditional logistic regression model. There was no evidence that seagrass cover or substrate explained patterns of use. The proximity of foraging locations relative to mangroves and to deep water were important at both spatial scales but had lower effect sizes (odds ratios) than time-integrated habitat availability and water depth, and the latter may only serve as a physical constraint on access. We found support that time-integrated habitat availability was a distinct resource attribute, had the greatest effect size (four-to eightfold change in relative probability of use), and best explained patterns of habitat use at the largest spatial scale. In studies of resource use where changes in resource availability are nonlinear or when strong constraints on access are imposed by behavior, incorporating time-integrated estimates of resource availability into analyses can improve insights into spatiotemporal patterns of resource use.
... Annual biomass estimates, litter fall, and production by species, were within realistic ranges (one standard deviation from the average; Table 4) of our field data and also within the ranges in published literature (Craft et al., 1995;Davis et al., 2006;Miao and Zou, 2012; Total biomass of all species in community Initial biomass for 900 m 2 area, receives flows from production. Field data; Zweig andKitchens (2008, 2009): 3500-315,000 g varying by species and community I Inundation Slows C. jamaicense production in wet years IF-THEN statement (Newman et al., 1996;Pezeshki et al., 1996;Childers et al., 2006). Slows production incrementally by minimum and maximum depths. ...
Patterned landscapes have long been a popular setting to test hypotheses about the effects of processes on ecosystem structure. The combination of scale-dependent and positive feedback theory is one of the most well-supported in current literature, each explaining separate aspects of patterned peatlands. These theories have been developed from dynamics in boreal peatlands and tested in boreal systems, but the mechanisms that control peat patterning in a sub-tropical system have yet to be acknowledged in theory. Statistical evidence for different mechanisms are present in the biophysical features of sub-tropical patterned peatlands, such as the ridge and slough landscape (RSL) within the greater Everglades wetland system. We use data from the RSL to test whether features of a sub-tropical, patterned peatland conform to positive and scale-dependent feedback patterning theories developed in boreal peatlands and use dynamic simulation to explain our results. The analysis of surface elements and nutrient differences within the RSL and our dynamic simulations indicate that positive and scale-dependent feedback may not be appropriate theories for sub-tropical peat patterning. Decomposition, rather than production, appears to be more important for abrupt microtopographical elevation differences, and differential nutrient concentrations are due to vegetation types, rather than increased evapotranspiration from greater vascular plant growth. Our model expands on the current theories for RSL maintenance, incorporating vegetation types and life history traits into differential peat deposition, which create the signature microtopographical differences found in the Everglades, and demonstrates that the underlying ecological patterning processes in sub-tropical peatlands are likely very different from boreal peatlands and require further discussion and study.
... Although it can become locally abundant under high-phosphorus conditions (Davis, 1991;Miao, Newman, & Sklar, 2000;Newman, Grace, & Koebel, 1996), it is typically not considered invasive, and it lacks the cosmopolitan distribution and global nuisance status of P. australis (Finlayson et al., 1983;Mal & Narine, 2004). Typha domingensis has well-developed cortical aerenchyma, and like P. australis, it can provide substantial oxygen to the rhizosphere (Chabbi, McKee, & Mendelssohn, 2000;Dunbabin, Pokorny, & Bowmer, 1988); thus, it may influence sediment N biogeochemistry by stimulating coupled nitrification-denitrification. ...
• Wetlands are often biogeochemical hotspots, and they can remove excess N via denitrification and assimilatory uptake. Wetlands are also susceptible to plant invasions, but the effect of invasive plants on denitrification in freshwater wetland sediments is not well‐studied.
• Two distinct mechanisms suggest the potential for invasive plants to alter denitrification. First, invasive plants often produce more biomass than non‐invasive species, thus potentially providing additional carbon (C) for denitrifiers. Second, some invasive wetland plants funnel more oxygen into the root zone than non‐invasive plants, potentially stimulating coupled nitrification–denitrification.
• Using the push–pull isotope pairing technique, we measured denitrification and coupled nitrification–denitrification in the sediments beneath monoculture plots of Phragmites australis and Typha domingensis, and beneath unvegetated sediments, in an urban wetland in Melbourne, Australia. We also measured pore water nutrient concentrations and calculated the diffusive flux of nutrients from the sediments into the overlying water column.
• We hypothesised that plots containing P. australis would have the highest denitrification and coupled nitrification–denitrification rates, followed by plots containing T. domingensis, with the lowest rates in the unvegetated plots, as a result of higher C and oxygen availability.
• Instead, we found that denitrification and coupled nitrification–denitrification rates were highly variable, with no difference among plot type. However, we did find that diffusive flux of ammonium from the sediments into the water column was lower in the vegetated plots than in the unvegetated plots, suggesting that vegetation enhances wetland N retention via plant assimilatory uptake.
... Increases in Cyperaceae and Typha have been related to fluctuations in water levels but also with water nutrient enrichment. Typha species thrives in areas of high nutrient input (i.e., nitrogen and phosphorous) mainly because of their fast growth rates and ability to take up nutrients rapidly (Newman et al., 1996;Miao and Sklar, 1998). The notable increase in Pediastrum 1680 to 1850 CE and Tetraedon peak that coincided with hemp maxima might also be related with eutrophication processes as it has been observed in other similar lakes with hemp retting . ...
Lakes with varved sediments are especially well suited for paleoecological reconstruction from annual to seasonal resolution. The interpretative power of these reconstructions relies on the availability of modern analogs with the same resolution. In this paper, we study the seasonal pollen sedimentation of a varved lake from the Central Pyrenees (Lake Montcortès) as a modern analog for the high-resolution reconstruction of Late Holocene vegetation and landscape dynamics. Seasonal samples were obtained from sediment traps that were submerged near the maximum water depth for a two-year period (from the Fall of 2013 to the Fall of 2015). Seasonal pollen sedimentation was compared with meteorological variables from a nearby weather station. Bulk pollen sedimentation, dominated by Pinus and Quercus, followed a clear seasonal pattern that peaked during the spring/summer (SS), coinciding with maximum temperature and precipitation, minimum relative humidity and moderate winds from the SSE. Pollen sedimentation lags (PSL) were observed for most pollen types as significant amounts of pollen were found in the traps out of their respective flowering seasons. Two pollen assemblages were clearly differentiated by their taxonomic composition corresponding to spring/summer and fall-winter (FW). This pattern is consistent with the existing interpretation of the sedimentary varves: specifically, that the varves are formed by two-layer couplets that represent the same seasonality. It is concluded that pollen sedimentation in Lake Montcortès exhibits a strong seasonal signal in the quantity of pollen, the taxonomic composition of the pollen and the relationships of the pollen to meteorological variables. Thus, varved sediments provide a powerful tool for paleoecological reconstruction at seasonal resolutions. This method could be useful not only for unraveling paleoenvironmental trends but also for identifying annual layers and therefore, dating the sediments, even in the absence of evident sedimentary laminations. A satisfactory explanation of pollen sedimentation lags will require more studies that examine internal lake dynamics (i.e. stratification vs. mixing) as well as pollen production and dispersal patterns.
... Moreover, the growth of various Typha spp. responded positively to increased water depth (by up to 60%) ( Newman et al. 1996). Typha orientalis responds to changes in water depth by producing large, thick rhizome storage organs, allowing it to maintain effective aeration under anoxic conditions for long periods of time ( Sharma et al. 2008). ...
Flooding regimes are a primary influence on the wetland plant community. Human-induced disturbance often changes the duration and frequency of flooding in wetlands, and has a marked influence on wetland plant composition and viability. Comprehensive studies of the environmental thresholds of wetland plants are required for the development of proper practices for wetland management and restoration after hydrological disturbance. This study provides a quantitative assessment of the establishment, growth, and community shifts in dominance of three emergent plant species (Scirpus tabernaemontani, Typha orientalis, and Zizania latifolia) typical of South Korean wetlands, under five hydrological regimes (waterlogged, low-level standing water, high-level standing water, intensive periodic flooding, and intermittent flooding) over four growing seasons. A mesocosm experiment was conducted in the campus of Seoul National University, South Korea. The number and biomass of shoots of Z. latifolia responded positively to increased water level and flooding frequency, while that of the other plants did not. Zizania latifolia outcompeted S. tabernaemontani and T. orientalis irrespective of hydrological regime. This study suggests that Z. latifolia can outcompete the other two macrophytes in the field. This study will improve our ability to predict the dynamics of wetland vegetation and so facilitate the formulation of wetland management and restoration strategies.
... Although some progress has been made because of these efforts (NRC, 2007(NRC, , 2014, large areas remain subjected to nutrient-laden water from irrigation, urban, and road stormwater runoff, eroded soils, and biological debris, all directly and swiftly transported downstream by agricultural drainage ditches (Makkinga et al., 1998). Phosphorous inputs have increased from pre-drainage conditions, allowing eutrophically dominant species such as cattail to expand beyond its small-stand distribution and compete with sawgrass in the northern Everglades (Newman et al., 1996;Noe et al., 2001;Childers et al., 2003;Weisner and Miao, 2004). While factors such as hydroperiod and fire regime can affect the relative distribution of cattail and sawgrass in an area, numerous studies have shown that nutrient changes are the controlling factor in the cattail/sawgrass competition (Davis, 1994;Childers et al., 2003;Gaiser et al., 2012). ...
Considerable research activity has been undertaken to characterize the effects of nutrient cycle changes on the distribution of plant communities in the Florida Everglades. Studies of constructed Everglades ecosystems at the mesocosm scale offer avenues for researching the complexities of these interactions. The objectives of this study were to describe the vegetation that developed in the Florida Everglades mesocosm in Washington, D.C., a greenhouse-sized constructed Everglades ecosystem in operation from 1987 to 2001. Literature on actual Everglades vegetation was used to make comparisons with the vegetation in the mesocosm. The entire standing herbaceous biomass was harvested from the mesocosm’s cattail and sawgrass communities, and samples of belowground biomass were taken from various points throughout. Dry weights of the samples revealed the highest overall aboveground biomass (2223 g m-2) in the mixed cattail/sawgrass community of the emergent marsh/herbaceous hummock section, and the lowest (1302 g m-2) in the grass prairie. The highest below ground biomass (4058 g m-2) was also found in the marsh/hummock, and the lowest (64 g m-2) was found in the marsh/pond. These biomass values fall within the ranges found in the literature on productivity of cattail and sawgrass communities. The distribution of the plant species fluctuated between the community sections, with species richness highest in the grass prairie and lowest in the marsh/pond. The fluctuations of plant assemblages between the community sections give evidence that the sections may represent the transition zone between tree islands and sawgrass marsh communities found in the wild. Soil and leaf nutrient contents were within expected ranges of their natural analogs, although no significant differences were seen between the cattail and sawgrass populations. Artifacts of the mesocosm were strongly evident, such as edge effects in community density, yet the ecological structure of the mesocosm was strikingly close to that found in the wild Everglades. Overall, the experience with the management, harvest, and study of the Florida Everglades mesocosm demonstrates the value of large-scale mesocosm studies for representation of ecological structures and functions.
This datasheet on Typha domingensis covers Identity, Overview, Distribution, Dispersal, Hosts/Species Affected, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Further Information.
Richly illustrated and packed with numerous examples, this unique global perspective introduces wetland ecology from basic principles to advanced applications. Thoroughly revised and reorganised, this new edition of this prize-winning textbook begins with underlying causal factors, before moving on to more advanced concepts that add depth and context. Each chapter begins with an explanation of the basic principles covered, illustrated with clear examples. More difficult concepts and exceptions are introduced only once the general principle is well-established. Key principles are now discussed at the beginning of the book, and in order of relative importance, enabling students to understand the most important material without wading through complex theory. New chapters on wetland restoration and wetland services draw upon practical examples from around the world, providing a global context, and a new chapter on research will be particularly relevant to the advanced student planning their own studies.
Richly illustrated and packed with numerous examples, this unique global perspective introduces wetland ecology from basic principles to advanced applications. Thoroughly revised and reorganised, this new edition of this prize-winning textbook begins with underlying causal factors, before moving on to more advanced concepts that add depth and context. Each chapter begins with an explanation of the basic principles covered, illustrated with clear examples. More difficult concepts and exceptions are introduced only once the general principle is well-established. Key principles are now discussed at the beginning of the book, and in order of relative importance, enabling students to understand the most important material without wading through complex theory. New chapters on wetland restoration and wetland services draw upon practical examples from around the world, providing a global context, and a new chapter on research will be particularly relevant to the advanced student planning their own studies.
Bolboschoenus planiculmis is a key wetland plant in the semi-arid regions of Songnen Plain, China, providing food and habitat for the endangered Siberian crane. B. planiculmis wetlands are being degraded by water shortages caused by anthropogenic activities and climate changes. However, the vegetation dynamics under hydrological fluctuations have been rarely reported. We conducted a two-year field investigation in B. planiculmis wetlands to determine the vegetation response to water level changes, and a comparative control experiment to examine the restoration effect of supplemental water on degraded community. We found that the community biomass was positively related with water depth under natural conditions, whereas plant diversity and richness were negatively related. The population density, biomass, and root/shoot ratio of B. planiculmis exhibited quadratic relationships with water depth. The optimum ecological threshold of water depth determining B. planiculmis populations was 11.2–36.1 cm. The control experiment demonstrated that water depth at 0–10 cm during the early growing season and 10–25 cm at later growing stages can enhance the dominance of B. planiculmis and help it outcompete other macrophyte species. Understanding the water requirement cycles of B. planiculmis is valuable for guiding water management plans for the rehabilitation of degraded natural wetlands.
Net ecosystem carbon balance is a comprehensive assessment of ecosystem function that can test restoration effectiveness. Coastal peatlands are globally important carbon sinks that are vulnerable to carbon loss with saltwater intrusion. It is uncertain how wetland carbon stocks and fluxes change during freshwater restoration following exposure to saltwater and elevated nutrients. We restored fresh water to sawgrass (Cladium jamaicense) peat monoliths from freshwater marshes of the Everglades (Florida, USA) that had previously been exposed to elevated salinity (~9 ppt) and phosphorus (P) loading (1 g P m⁻² y⁻¹) in wetland mesocosms. We quantified changes in water and soil physicochemistry, plant and soil carbon and nutrient standing stocks, and net ecosystem productivity during restoration. Added fresh water immediately reduced porewater salinity from >8 to ~2 ppt, but elevated porewater dissolved organic carbon persisted. Above- and belowground biomass, leaf P concentrations, and instantaneous rates of gross ecosystem productivity (GEP) and ecosystem respiration (ER) remained elevated from prior added P. Modeled monthly GEP and ER were higher in marshes with saltwater and P legacies, resulting in negative net ecosystem productivities that were up to 12× lower than controls. Leaf litter breakdown rates and litter P concentrations were 2× higher in marshes with legacies of added saltwater and P. Legacies of saltwater and P on carbon loss persisted despite freshwater restoration, but recovery was greatest for freshwater marshes exposed to saltwater alone. Our results suggest that restoration in nutrient-limited freshwater wetlands exposed to saltwater intrusion and nutrient enrichment is a slow process.
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Human-induced eutrophication has altered ecological processes in aquatic ecosystems. Detection of ecological changes is a prerequisite for protecting ecosystems from degradation. In this study, nitrogen stable isotopes (δ ¹⁵ N) in fish are evaluated as indicators of environmental changes in south Florida wetlands. Stable nitrogen isotope (δ ¹⁵ N) data of select fish species and water quality collected from the Florida Everglades between the 1990s and 2000s were used to assess the relationship between total phosphorus concentrations and δ ¹⁵ N ratios. The δ ¹⁵ N ratios in nine of ten select fish species increase significantly as total phosphorus concentration in the surface water increases. There were significant relationships between total nitrogen concentration in the surface water and δ ¹⁵ N ratios in several fish species. The pattern of changes in δ ¹⁵ N ratios along nutrient gradients suggests that increased eutrophication is recorded as the δ ¹⁵ N ratios in fish. The lack of human wastewater loading, the dominance in agricultural runoff and the high TN:TP ratio suggest that phosphorus is the limiting factor driving ecosystem productivity and the changes of δ ¹⁵ N ratios in fish. Results from this analysis demonstrate that δ ¹⁵ N ratios in fish integrate biotic responses to eutrophic process over time and could be a robust indicator for early ecological changes.
This study was concerned with the assessment of soil environment quality and to test the suitability of Atriplex nummularia for bio-indicating of soils heavy metals. To achieve these goals were examined the concentrations of Pb, Cd, Co, Ag and Cr accumulation in the different organs of plants in the context of different soil in Al Najaf-Al Ashraf, Iraq in 2016. The heavy metals in Deserts soil were found to increase in the order of Cr< Ag < Cd < Co <Pd , while in agriculture soil were increased in Cr < Ag < Cd <Pd< Co. Deserts soil was the highest concentration of heavy metal except for Co. The soils contents of Cd were about five times and Co were about one and a half times above the worldwide range. On the other hand, Cr, Ag and pb concentrations were below the reference ranges of the United States and Chinese soils. The heavy metal bioaccumulation decreased according to the order of root> leaf for Pb and Cd ; and leaf > root for Co, Ag andCr. The mean (transfer factor from root to stem) TF(Rt/SE) in desert soil for (Pb, Cd, Co and Cr) and the mean (transfer factor from above ground to below ground) TF (AG/BG) for Pb were more than one. Agricultural soil showed that the mean TF(Rt/SE) for (Cd and Cr) and the mean TF (AG/ BG) for Co were more than one. The higher transmission ratio of this metal in Atriplex nummularia shoots make it suitable for phytoextraction from soil. There was a significant linear correlation between the concentration of heavy metals in the root of Atriplex nummularia and that in the soil. This result suggests that Atriplex nummularia can be regarded as bio-indicator for heavy metals pollution of soils.
Floristic quality assessments (FQA) using floristic quality indices (FQIs) are useful tools for assessing and comparing vegetation communities and related habitat condition. However, intensive vegetation surveys requiring significant time and technical expertise are necessary, which limits the use of FQIs in environmental monitoring programs. This study modified standard FQI methods to develop a rapid assessment method for characterizing and modeling change in wetland habitat condition in the northern Everglades. Method modifications include limiting vegetation surveys to a subset of taxa selected as indicators of impact and eliminating richness and/or abundance factors from the equation. These modifications reduce the amount of time required to complete surveys and minimizes misidentification of species, which can skew results. The habitat characterization and assessment tool (HCAT) developed here is a FQA that uses a modified FQI to detect and model changes in habitat condition based on vegetation communities, characterize levels of impact as high, moderate, or low, provide predictive capabilities for assessing natural resource management or water management operation alternatives, and uniquely links a FQI with readily accessible environmental data. For application in the northern Everglades, surface water phosphorus concentrations, specific conductivity, distance from canal, and days since dry (5-year average) explained 67% of the variability in the dataset with > 99.9% confidence. The HCAT approach can be used to monitor, assess, and evaluate habitats with the objective of informing management decisions (e.g., as a screening tool) to maximize conservation and restoration of protected areas and is transferable to other wetlands with additional modification.
Nutrient enrichment—particularly with respect to phosphorus—has long been a major concern in the Everglades (see Chap. 2, Volume I). This perturbation is of keen interest with respect to the Everglades mercury (Hg) problem because the biogeochemical cycling of Hg in aquatic ecosystems is intrinsically linked to trophic state through multiple pathways, including the effects of nutrient status on food web structure and dynamics, in situ particle production, and redox dynamics in surficial sediments (see Fig. 1.1, Chap. 1, this volume). As a result, decision makers charged with the responsibility of restoring the Everglades must also consider the resultant impacts of management strategies on not just trophic state dynamics, but also the linked effects of those strategies on Hg biogeochemical cycling and trophic transfer. This chapter thus reviews phosphorus enrichment in the Everglades and its effects on Hg biogeochemical cycling, including its effects on methyl mercury production related to perturbations in redox dynamics in particular.
This study was concerned with the assessment of soil environment quality and to test the suitability of Atriplex nummularia for bio-indicating of soils heavy metals. To achieve these goals were examined the concentrations of Pb, Cd, Co, Ag and Cr accumulation in the different organs of plants in the context of different soil in Al Najaf-Al Ashraf, Iraq in 2016. The heavy metals in Deserts soil were found to increase in the order of Cr< Ag < Cd < Co <Pd , while in agriculture soil were increased in Cr < Ag < Cd <Pd< Co. Deserts soil was the highest concentration of heavy metal except for Co. The soils contents of Cd were about five times and Co were about one and a half times above the worldwide range. On the other hand, Cr, Ag and pb concentrations were below the reference ranges of the United States and Chinese soils. The heavy metal bioaccumulation decreased according to the order of root> leaf for Pb and Cd ; and leaf > root for Co, Ag andCr. The mean (transfer factor from root to stem) TF(Rt/SE) in desert soil for (Pb, Cd, Co and Cr) and the mean (transfer factor from above ground to below ground) TF (AG/BG) for Pb were more than one. Agricultural soil showed that the mean TF(Rt/SE) for (Cd and Cr) and the mean TF (AG/ BG) for Co were more than one. The higher transmission ratio of this metal in Atriplex nummularia shoots make it suitable for phytoextraction from soil. There was a significant linear correlation between the concentration of heavy metals in the root of Atriplex nummularia and that in the soil. This result suggests that Atriplex nummularia can be regarded as bio-indicator for heavy metals pollution of soils.
While seldom integrated within coastal archaeological research in Southeastern North America, vegetation histories derived from palynological data offer valuable records of ancient landscape transformations driven by climatic flux, sea-level oscillations, and anthropogenic modifications. In this paper, we develop a paleo-historical-ecological reconstruction from preliminary analyses on fossil pollen assemblages preserved within marsh, hammock, and shell-midden soils at the Crystal River site (8CI1), a mound center on Florida’s west-central coast occupied throughout the first millennium AD. When contextualized alongside paleoenvironmental records from western Florida and farther afield, our analysis suggests that the nature and timing of late-Holocene climatic changes varied little between different sub-regions of Florida’s Gulf Coast, but also that manifestations of eustatic sea-level flux may have been highly localized.
This study was concerned with the assessment of soil environment quality and to test the suitability of Atriplex nummularia for bio-indicating of soils heavy metals. To achieve these goals were examined the concentrations of Pb, Cd, Co, Ag and Cr accumulation in the different organs of plants in the context of different soil in Al Najaf-Al Ashraf, Iraq in 2016. The heavy metals in Deserts soil were found to increase in the order of Cr< Ag < Cd < Co <Pd , while in agriculture soil were increased in Cr < Ag < Cd <Pd< Co. Deserts soil was the highest concentration of heavy metal except for Co. The soils contents of Cd were about five times and Co were about one and a half times above the worldwide range. On the other hand, Cr, Ag and pb concentrations were below the reference ranges of the United States and Chinese soils. The heavy metal bioaccumulation decreased according to the order of root> leaf for Pb and Cd ; and leaf > root for Co, Ag andCr. The mean (transfer factor from root to stem) TF(Rt/SE) in desert soil for (Pb, Cd, Co and Cr) and the mean (transfer factor from above ground to below ground) TF (AG/BG) for Pb were more than one. Agricultural soil showed that the mean TF(Rt/SE) for (Cd and Cr) and the mean TF (AG/ BG) for Co were more than one. The higher transmission ratio of this metal in Atriplex nummularia shoots make it suitable for phytoextraction from soil. There was a significant linear correlation between the concentration of heavy metals in the root of Atriplex nummularia and that in the soil. This result suggests that Atriplex nummularia can be regarded as bio-indicator for heavy metals pollution of soils.
The rapid development of whiteleg shrimp farming in the Mekong delta of Vietnam has an adverse impact on the environment due to large amount of nitrogen and phosphorus content in wastewater and pond sludge/sediment. Phytoremediation is a promising technique to use plant for mitigating environmental impacts from intensively whiteleg shrimp culture. Growth responses, nitrogen and phosphorus removal of Typha orientalis and Scirpus littoralis were assessed at three water levels of +15 cm, +30 cm and +45 cm. They were arranged in a completely randomized design with three replications. The plants were supplied wastewater from intensive whiteleg shrimp tanks once every two weeks. Waterlogged assessment was conducted for 71 days. Water levels significantly affected plant growth rate and nutrient removal capacity. S. littoralis grew well with a lower mortality rate and had no statistical reduction of biomass compared to T. orientalis at the highest water level of +45 cm. T. orientalis had the best perfromance in growth and biomass responses to waterlogged at water levels of +15 cm and +30 cm. The results indicated that S. littoralis was the best of choice to grow in waterlogged condition of the shrimp pond for maintaining water quality.
Background: Wetlands are heterogeneous and dynamic ecosystems, very susceptible to invasions or local extinctions by the effects of invasive or over-dominant plant species. Resistance to invasion in wetlands that suffer disturbances such as fires has not been thoroughly studied. When Phragmites australis (common read) is present, its interaction with disturbance factors has led to local extinction of many native species. In a previous study, it was determined that harvesting is an effective control method for this species. But removal of aerial parts of this species generates many fragments that might propagate the species. Goals: Evaluate under controlled conditions the invasive potential of fragments of Phragmites australis in plant communities dominated by native plant species that are subjected to frequent human-made disturbances, such as fire, under controlled conditions. Methods: We carried out an experiment that consisted of two assays in 36 mesocosms with canopies of Schoenoplectus americanus. Results: Phragmites australis was practically not able to establish itself after the loss of the S. americanus canopy following fires, because the canopy of this last species recovered rapidly. Survival and growth were slightly higher in mesocosms with low disturbance (27.7% and 55.9 cm in the first assay, and 9.4%, and 60.6 cm in the second assay), when compared with controls (8.5% 35.3 cm, and 7.4% and 86.7 cm), because in control units the canopy of S. americanus was a permanent barrier to the development of P. australis. Height differences among burned and control mesocosms after the first fire event were significant (p =0.002) but not after two consecutive years of burning (p =0.085), because the few plants that survived in control units reached considerable height. Conclusions: The risk of establishment of the fragments of Phragmites australis that are generated during harvesting is low even after major disturbances of native vegetation cover.
Wetlands are biogeochemically active ecosystems where primary production and respiration interact with physico-chemical conditions to influence nutrient availability across spatio-temporal scales. The effect of episodic disturbances on water quality dynamics within wetlands is relatively unknown, especially in large oligotrophic wetlands such as the Everglades. We describe a range of episodic disturbance events and their impacts on the spatio-temporal dynamics of surface water total N (TN) and total P (TP) concentrations in the Everglades as a means to understand their effect and legacies. Water quality monitoring along the two principal drainages-Taylor Slough (TS) and Shark River Slough (SRS)-has been ongoing since 2000, spanning myriad disturbances ranging from high-energy storms such as Hurricane Wilma in 2005 to a record cold event in 2010 and large fires. Local events include pulsed rainfall, low marsh stage, and stage recession and recovery (i.e., droughts and subsequent dry-to-wet transitions). The deposition of marine-derived sediment from Hurricane Wilma corresponded with a doubling of TP in SRS mangrove sites (from 0.39 to 0.84 lmol/L) before recovering to pre-disturbance mean after 5-6 yr. A brief increase in TP within one week of the 2010 cold event was followed by delayed spikes in TN (>1000 lmol/L) and TN:TP exceeding 5000 after one month. In 2008, a large fire in upper SRS prior to the wet season caused a lagged TP pulse at downstream locations SRS2, SRS3, and possibly SRS4. TP also varied negatively with depth/stage in marsh sites and positively with salinity in estuarine sites, reflecting physical concentration or dilution effects. In upper TS, TP varied according to extremes such as high rainfall and low stage relative to normal conditions. Although excess P in the Everglades is generally derived from anthropogenic upland or natural marine sources, episodic disturbance mobilizes internal sources of nutrients along an Everglades freshwater-to-estuary continuum, affecting water quality from days to years depending on disturbance type and intensity. The capacity for resilience is high in coastal wetland ecosystems that are exposed to high-energy tropical storms and other episodic events, even in the highly managed Florida Everglades.
As part of restoration efforts of Holey Land Wildlife Management Area (HWMA) in the northern Everglades, a pump station in the northwest corner began delivering water from the Miami Canal in 1991. In 2005, Hurricane Wilma damaged the pump, rendering it non-functional until September 2014. These events provided a unique opportunity to examine the impacts of an active water schedule on the vegetation structure of HWMA. Results of linear-regression models show a drastic increase in Typha domingensis (Southern Cattail) abundance during the period when the pump was active and a marked decrease of this species after pump failure. This change was attributable to increased nutrient inputs from canal water pumped into the area. Changes in Cladium jamaicense (Sawgrass) cover may have a lag response to fire activity.
Disturbances such as fire or flood, in addition to changing the local magnitude of ecological, hydrological, or biogeochemical processes, can also change their functional connectivity—how those processes interact in space. Complex networks offer promise for quantifying functional connectivity in watersheds. The approach resolves connections between nodes in space based on statistical similarities in perturbation signals (derived from solute time series) and is sensitive to a wider range of timescales than traditional mass-balance modeling. We use this approach to test hypotheses about how fire and flood impact ecological and biogeochemical dynamics in a wetland (Everglades, FL, USA) that was reconnected to its floodplain. Reintroduction of flow pulses after decades of separation by levees fundamentally reconfigured functional connectivity networks. The most pronounced expansion was that of the calcium network, which reflects periphyton dynamics and may represent an indirect influence of elevated nutrients, despite the comparatively smaller observed expansion of phosphorus networks. With respect to several solutes, periphyton acted as a “biotic filter,” shifting perturbations in water-quality signals to different timescales through slow but persistent transformations of the biotic community. The complex-networks approach also revealed portions of the landscape that operate in fundamentally different regimes with respect to dissolved oxygen, separated by a threshold in flow velocity of 1.2 cm/s, and suggested that complete removal of canals may be needed to restore connectivity with respect to biogeochemical processes. Fire reconfigured functional connectivity networks in a manner that reflected localized burn severity, but had a larger effect on the magnitude of solute concentrations.
Impoundment has significantly reduced the volume of fresh water to Florida Bay. As a result, bay waters are now more saline in more locations and for longer periods of time than under premanaged conditions. Numerous effects on biota and biotic processes in the bay and southern Everglades ecotone have been documented or implicated. Reduced freshwater inflow is also implicated as one of a complex series of factors in the mass mortality of seagrasses and hypersalinity is likely a factor in dieback of mangroves. Excessive amounts and unnatural timing of freshwater delivery can also adversely affect biota. A sudden release of greatly elevated volumes of freshwater from the C-111 canal resulted in the mortality of many estuarine organisms in Manatee Bay. -from Authors
The objective of this study was to examine the effects of preemption on rates of competitive displacement and on competitive outcomes for two Typha species (T. latifolia, TL, and T. domingensis, TD) growing along gradients of water depth. Evidence from several experiments indicated that the relative competitive abilities of the two species were size dependent. When TL and TD competed as small seedlings, TD was generally favored while TL was the better competitor when the plants were larger before beginning to compete. Because of this effect, initial density was determined to influence strongly the early outcome of competition. When seeds were sown at high densities, TD gained an early advantage; at lower densities TL was the better competitor. At very low densities, such as when the species competed as clones, TL was very much the better competitor. In the absence of preemption, the results showed that differences in germination, seedling growth, and competitive ability act to create an initial segregation of species at the waterline where establishment occurs. TL is upslope and TD downslope initially, but as the species spread downslope, TL progresses faster because of its greater capacity for vegetative spread, and the result is a widespread overlap along the gradient. Studies of the rate of competitive displacement between established plants yielded an estimate of slightly
Typha latifolia L., common cattail, Typha angustifolia L., narrow-leaved cattail, and Typha xglauca (T. angustifolia × T. latifolia), hybrid cattail, are herbaceous perennials found in wet or saturated soils and aquatic sediments in marshes, wet meadows, lakeshores, pond margins, seacoast estuaries, roadside ditches, bogs, and fens in Canada and the U.S.A. Typha latifolia is a cosmopolitan species found in all provinces of Canada while T. angustifolia and T. xglauca have spread within this century from the coastal areas, largely on the Atlantic coast, through the southern portions of the eastern and central provinces to south-central Manitoba. Considerable variation in T. xglauca exists and our understanding of this taxon is presently limited. Ecotypic variation has been described for the species. Typha is considered to be a weed under certain circumstances though it has beneficial value for waterfowl and wildlife. Typha can be found in a very broad range of habitat types ranging from early to late successional. Typically, T. angustifolia and T. xglauca are more limited in their ecological range than T. latifolia, being associated with saline or disturbed areas. Within habitats, T. latifolia is typically upslope of T. angustifolia with T. xglauca characteristic of more intermediate water depths though much more work is needed on the ecological relations of these taxa. An extensive literature exists on the germination, growth, and abundance of these highly productive taxa.Key words: Cattail, Typha, Typha angustifolia, Typha angustifolia × Typha latifolia, Typha xglauca, Typha latifolia
Diurnal and seasonal patterns of CO2 concentration ([CO]) in leaf gas spaces were measured to better understand the relationship of sediment-derived CO2 to photosynthesis in the emergent wetland species, Typha latifolia L. (cattail). Leaf [C02] was above 2,000 Al/liter at dawn on all but the first sampling date. At all sampling dates, leaf [CO2] declined to near atmospheric [C02] at midday and rose to well above atmospheric [C02] in the late afternoon. The maximum leaf [C02] varied with sampling date and was over 18 times atmospheric levels (over 6,300 ,ul/liter) in August. Based on measurement ofphoton flux density and temperature, the diurnal pattern in leaf [C02] may be generally controlled by expected photosynthetic rates. It is hypothesized that seasonal variation in leaf [C02] may be a function of variation in microbial (soil) respiration. Using dye and slight pressurization, it was confirmed that gas spaces in rhizomes were interconnected with the gas spaces in leaves through the rhizome-shoot transition. From anatomical measurements, it was also estimated that over 50% of total leaf volume was occupied by gas spaces and that most of the total gas-space volume in plants was in the shoot. Photosynthetic rate in C3 plants, like cattail, can increase with increasing [C02] under natural conditions. For this reason, cattail and other emergent wetland plants possessing continuous gas-space pathways appear to have a significant carbon supplement as compared to other C3 plants growing in well-aerated soils. The purpose of this study was to determine the diurnal and seasonal patterns of CO2 concentration ([C02]) in leaf gas spaces for the common wetland emergent, Typha la
The two species of Typha common in the southeastern United States, T. latifolia and T. domingensis differ substantially in their tolerance to deep water. The objective of this study was to examine the morphology and biomass allocation of these two species to determine if they have similar phenotypic responses to water depth. Replicate monocultures of the two species were established at a range of water depths in an artificial pond and allowed to grow for three growing seasons. At the end of the experiment, subsamples were harvested for determination of plant morphology as well as above- and belowground biomass. Both species of Typha showed increases in maximum height with increasing depth. The species less tolerant to deep water (T. latifolia) allocated more of its biomass to leaves with increasing water depth. In contrast, the deep water species (T. domingensis) showed increased total size of each ramet but a fixed percentage of biomass in leaves with increasing water depth. Both species had a decreasing incidence of flowering and decreasing shoot density with increasing water depth. In general, these species conform to expectations based on considerations of how their carbon budgets would be affected by water depth.
Over a 2-year period, nutrients (N, P and K) were added to mixtures of Typha latifolia L. and T. domingensis Pers. growing across a water-depth gradient in order to determine: (1) the relationship between nutrient limitation and water depth; (2) the differential effect of nutrient addition on species performance. In addition, sediment characteristics were determined for untreated mixtures, monocultures and bare sediment.Additions of nutrients resulted in a rapid increase in total shoot density compared to controls. Increases in total shoot biomass, however, occurred gradually over time in response to nutrient additions. Nutrients enhanced T. latifolia in shallow to medium depths while T. domingensis was enhanced in medium to deep waters.Compared to bare sediment, pH was not affected by the presence of either species. Redox potential, however, was increased by T. domingensis in medium depths while unaffected by T. latifolia. Coupled with the observation that T. domingensis is capable of growing in deeper water than T. latifolia, the Eh data suggest that T. domingensis may have a greater capacity to aerate its roots and rhizosphere.Sediment ammonium concentrations were reduced by c. 90–95% by plant growth while potassium was reduced by c. 35–55%. Phosphate was unchanged compared to bare sediment. These results suggest that sediment nitrogen was the most limiting nutrient.
Five freshwater marsh plant species exhibited different root metabolic responses when flooded to three water depths in field macrocosms. The capacity for alcoholic fermentation (as indicated by alcohol dehydrogenase activity) increased and remained at a relatively high level in the roots of the least flood-tolerant species, Scolochloa festucacea, but was not stimulated significantly or only temporarily in the more tolerant species, Scirpus acutus, Scirpus validus, Typha glauca, and Phragmites australis. During the first month of flooding, alcohol dehydrogenase activity showed a positive relationship with flooding depth and a negative relationship with soil redox potential. Malate accumulated in the roots of S. acutus, S. validus, and to a lesser extent in P. australis in response to flooding; concentrations showed a significant positive relationship with water depth and a significant negative relationship with soil redox potential during the first month of flooding. Differences in root metabolism among the five species were still evident after 1 year of continual flooding. Root specific gravities and air space cross-sectional volumes demonstrated potential species differences in root resistance to oxygen movement and root oxygen volume, respectively. The results suggest that the observed metabolic response reflected differential aeration of the roots resulting from differences in root structure and soil oxygen demand (reducing power).
Based on a 1989 symposium at Key Largo, Florida, the book focuses on the integrated interrelated roles of ecosystem size, disturbance patterns and hydrology as determinants of large-scale ecosystem restoration. Following the examination of Everglades issues in a broader perspective, the chapters are organized to develop the theme, established in an introductory synthesis, of the ecological concepts of stability, dynamics, and persistence as manifested in the spatial and temporal patterns of ecosystems, based upon examples from other systems. This sets the stage for the examination of Everglades ecosystem function in increasing levels of complexity. The spatial and temporal characteristics of the physical forces that drive the Everglades ecosystem - geology, sea level, climate, hydrology, and fire - are described in six chapters and integrated in a synthesis chapter. This leads to the examination of vegetation response to ecosystem driving forces in chapters that analyze community components and determinants of composition, invasion by the exotic Melaleuca quinquenervia, vegetation response to eutrophication, the ecology of periphyton communities, and ecological implications of landscape-level change. A synthesis chapter relates vegetation pattern and process to physical driving forces and biological processes. Faunal responses to these are then examined in chapters on the Everglades small-fish assemblage, American alligator, snail kite, interactions between Florida panther and white-tailed deer, and five chapters on wading bird dynamics. The section ends with a synthesis chapter on faunal patterns and processes. The final section provides overviews of the Everglades, past and present, as foundations for ecosystem restoration. Twenty-eight chapters are abstracted separately, mostly in Ecological Abstracts. -after Editors
The Everglades - a huge freshwater marshland and, in large part, peatland - developed in recent geologic time during a globally controlled convergence of both climatic change and sea level rise within a shallow bedrock trough located in south Florida. The recession of glaciers in northern North America at the end of the Pleistocene period and the change to a subtropical climate in south Florida provided both the abundant precipitation and the seasonal rainfall climate necessary for the generation of the Everglades wetland ecosystem. The rising sea level has undoubtedly retarded runoff and downward leakage out of the trough and helped to retain water within the Everglades basin. This, in turn, has allowed thick accumulations of peat (3-3.7 m) to develop within the deeper parts of the basin. The eastern coastal ridge, which was necessary to retain water within and in part defines the Everglades basin, owes its origin to marine geologic deposition which last occurred during the Sangamon interglacial age (about 125 000 years before present [YBP]), when sea level was up to 8 m above the present level. -from Authors
Since the turn of this century, a half of the 1.2 milion ha once covered by Everglades wetlands has been converted for human uses of agriculture and development. Three of seven predrainage landscapes, a custard apple forest (dominated by Annona glabra, peripheral wet prairie, and cypress forest Taxodium distichum) have disappeared completely. Three-fourths of a dense, monotypic sawgrass plain (Cladium jamaicense) that once covered the N Everglades has been replaced by agricultural crops. The other landscape units, including the wet prairie-slough-sawgrass-tree island mosaic, the sawgrass-dominated mosaic, and the southern marl marshes, have decreased in spatial extent to the lesser degree. Functional losses to the Everglades ecosystem that have accompanied landscape and plant community change appear to include 1) reduction in spatial extent of system aquatic productivity with loss of half of the ecosystem; 2) reduction in aquatic productivity of the southern Everglades due to shortened hydroperiods and interrupted flows as a result of development of marshes upstream; 3) reduction in cover of wet prairie and slough and related aquatic productivity in the remaining system; 4) loss of habitat diversity at the landscape and community level, and 5) reduction in early dry season feeding habitat of wading birds. Extended hydroperiods and flows during most years, punctuated by severe fires during periodic drought years, appear to be temporal patterns that supported Everglades landscape patterns and functions prior to drainage and development. Allowing such natural disturbance patterns to operate at full impact is a fundamental guideline for Everglades ecosystem restoration. -from Authors
Recent and historical satellite remote sensor data were used to inventory aquatic macrophyte changes within the Florida Everglades Water Conservation Area 2A using Landsat Multispectral Scanner (MSS) and Spot High Resolution Visible (HRV) multispectral data. The method required a single base year of remotely sensed data with adequate ground reference information. Historical remotely sensed data were 'normalized' to the base year's radiometric characteristics. Statistical clusters extracted from each data of imagery were found in relatively consistent regions of multispectral feature space and labeled using a 'core cluster approach'. Wetland classification maps of each year were analyzed using 'post classification comparison' change detection techniques to produce maps of 1) cattail change and 2) change in the 'sawgrass/cattail mixture' class.
This chapter illustrates the developments in the field of aeration since 1960, which have culminated in the modeling of the oxygen movements within the plant. The chapter collates the mathematical approaches to the aeration process and explains the concepts of modeling in a simplified manner. It is noted that the environment exerts a considerable influence on the directional flow of the respiratory gases within the plant and the directional exchange with the atmosphere. Oxygen can enter the plant body in a variety of ways. In non-aquatic species, the stomata and lenticels provide paths of low resistance for the entry and exit of both oxygen and carbon dioxide. In submerged astomatal aquatics, surface permeabilities are sufficiently high to allow the necessary gas transference. Plants rooted in unsaturated soils are exposed to an oxygen-rich environment over the greater part of their shoot and root surfaces. Oxygen enters the plant in the combined state as water. As water, it is transported from root to shoot in the xylem where a proportion is finally released into the liquid phase within the chloroplasts during the photolysis stage of photosynthesis.
Experiments were conducted in situ on isolated plots in a marsh to assess the capability of the system for renovating wastewater. Artificial enrichment of sawgrass did not produce increased growth, even though nutrients were assimilated. Thus, growth was not nutrient limited. Weekly application of 2.2 kg/ha of phosphorus increased tissue levels fivefold after 22 wk. However, this increase represented only 12% of the amount applied. The marsh system seems to have a limited capacity for assimilating nutrients. This capacity was stressed after 3 wk and overloaded by 8 wk at a continuous rate of enrichment. Because of this capacity for nutrient absorption, it was unlikely that sawgrass could be used to renovate wastewater efficiently with high nutrient concentrations.
Recent (1964-1989) rates of peat accretion and nutrient accumulation were measured to characterize the effects of altered hydroperiod and nutrient regimes on the nutrient storage capacity of the Everglades ecosystem. Accretion rates were highest in areas of extended hydroperiod (2.8-3.2 mm/yr) and/or phosphorus enrichment (4.0 mm/yr) and lowest in areas of reduced hydroperiod (1.6-2.0 mm/yr). Accumulation rates of N and organic C were primarily a function of peat accretion rates. Phosphorus accumulation was controlled by both peat accretation and increased soil P content. Soil P concentrations in an area receiving N and P enriched agricultural runoff were 2-3 times higher than at unenriched locations. The findings suggest that nutrient-enriched agricultural drainage has contributed to increased rates of peat accretion and phosphorus accumulation in areas of the northern Everglades during the past 25-30 yr. -from Authors
Marshland drainage and water regulation have greatly altered the Florida Everglades. One of the most visible ecological impacts has been a drastic decline in nesting populations of wading birds, and several specific hypotheses have been advanced to explain the decline. Recent efforts at ecological restoration have concentrated on reestablishing more natural seasonal hydropatterns in freshwater marsh areas now used extensively by the wading birds. However, nesting colonies were originally concentrated along the estuarine mangrove edge of the system rather than around upstream marshes. Hydrological simulation models have been used to reconstruct what hydrological conditions might have been like in the natural system, and these simulations indicate that freshwater pools near and flows to the estuary have been drastically reduced, especially late in the annual spring drying season. An experimental program of increased water releases to the estuary could be used to test whether estuarine restoration is a necessary condition for recovery of wading bird populations. This program would require a substantial commitment to deliver runoff from the Everglades Agricultural Area into the marshes, and to minimize water diversions for flood control and well field recharge
Through a series of time steps of 3-5 years (1952-90), the chronology of structural installations and modifications is traced, reflecting an evolution of objectives from flood control to water supply and, more recently, to redress adverse environmental impacts. Water flows and levels in the remaining system are controlled by regulation schedules for Lake Ikeechobee and the Water Conservation Areas, which have evolved parallel to structural modifications. The environmental consequences of the construction of appurtenant works in the Everglades suggests that nothing short of a major reconfiguration of the structural works of the Central and Southern Florida Project system is needed to repair the Everglades while providing for the human needs of the region. -from Authors
Flooding of soil rapidly depletes soil oxygen and alters plant metabolism, thereby inhibiting growth. Reduced growth is preceded by stomatal closure; reduced photosynthesis, carbohydrate translocation, and mineral absorption; as well as altered hormone balance. Flood tolerance varies widely among plant species, cultivars, and ecotypes and is associated with both morphological and physiological adaptations.
Investigations were conducted in 1971 and 1972 to characterize typical stands of sawgrass (Cladium jamaicense Crantz) in the southern Everglades. Estimates were obtained of standing crop, plant density, stem length, leaf numbers, growth rate, and nutrient relationships in plant tissue, soil, and water. Measurements were also made of daily rainfall and water depths. These various parameters were estimated monthly over a 12-18 mo period in mature stands, as well as in stands regrowing after wild fires. The mature stands showed little seasonal variation in standing crop, plant density, and concentration of most inorganic nutrients. Plant nutrient requirements were estimated to be low, because tissue levels of nutrients were low as compared to those of other species of Everglades macrophytes. Copper (Cu) and phosphorus (P) were particularly low. Levels of available nutrients in soil varied, with no seasonal pattern. Most nutrients were in adequate supply, except that available nitrogen (N), P, potassium (K) and Cu were generally very low. Reserve soil supplies of N and P were plentiful, but not of K. Accumulation of K in sawgrass leaves was more closely related to reserve supplies in soil than to available soil supplies. Waters in the marsh contained on an average 3%, 10%, and 8%, respectively, of the N, P, and K contained in a comparable area of sawgrass standing crop. Concentration of most nutrients in culms regrowing after fires was high during early growth stages, but decreased to levels found in older culms after 3-5 mo. Conenctrations of calcium (Ca), iron (Fe), and zinc (Zn) were exceptions, however. During the 1st year's growth after fires, 1 ha of sawgrass had accumulated 48 kg N, 1.8 kg P, and 38 kg K. After 18 mo growth, burned stands of sawgrass had produced only 38% of the standing crop contained in unburned mature stands. The apparent low nutrient requirements of sawgrass may partially explain the dominance of this plant in the marsh community.
The simulation is accomplished by eliminating the man-made modifications to the landscape (canals, structures, pumps, etc.) from an existing calibrated and verified regional hydrologic model of today's managed system. The Natural System Model was developed to estimate surface water flows and stages. Comparisons were made between the results of the natural and managed system models to provide some insight in evaluating alternatives for future restoration initiatives. However, the lack of available historical information on past hydrological and ecological conditions prevented sufficient modifications of the data sets to reflect what is generally perceived as predrainage or preproject conditions. Greater spatial and temporal extent of surface water depths occurred under natural conditions. -from Authors
The Florida Everglades developed as a nutrient-poor, rain-fed eco- system. However, for the past 30 yr, the Everglades have received nutrient-enriched surface water runoff from the adjacent Everglades Agricultural Area (EAA). This study examines the response of a pristine wetland, Water Conservation Area 1 (WCA 1), part of the northern Florida Everglades, to nutrient loading as documented by soil nutrient concentrations. During 1979 to 1988, WCA 1 received 138 t total P (TP) and 4919 t total N (TN), retaining 53% of the TP load and 58% of the TN load. Analyses of the spatial distribution of soil N and P showed steep gradients of TP along the western canal boundary, adjacent to inflow points importing EAA runoff. Surficial soils (0-10 cm depth) at interior marsh sites had a mean TP concentra- tion of 368 mg kg ', compared with 1028 mg kg ' measured at sites adjacent to the western canal. Similar trends were observed for soil Ca and Mg, while C and N did not show the same boundary effects on spatial enrichment. Nutrient-enriched sites also had higher porewater soluble reactive P (SRP; 0.15 mg L"1) and NH4-N (1.65 mg L~J) than unenriched sites (SRP = 0.02 mg L'1, NH^N = 0.85 mg L-'). Of the 90 sites sampled, 66 sites consisted of sloughs and sawgrass (Cladium jamaicense Crantz); the remaining 24 sites were either cattail (Typha spp.) dominated or had a significant cattail presence. These 24 cattail sites were closest to the nutrient inflow areas and had the highest soil nutrient concentrations.
A nutrient front encomapssing approximately 8000 ha has developed in a northern Everglades marsh, Water Conservation Area 2A(WCA-2A), during the last three decades from surface water P and N loading, in addition to atmospheric inputs. Soil cores (0-60cm) and plant tissue were collected from WCA-2A: Site N (northern), Site C (central), and Site S (southern), respectively. Although N loading was approximately 10-fold greater at Site N compared with Sites C and S, no significant difference in total N was found between sites at any soil depth. In contrast, P accumulated threefold in soils at Site N compared with Site S. Plant tissue N/P ratios at Site N and C were lower compared with Site S. The data suggest P may be an important nutrient limiting primary productivity in the Everglades and that Ca-P precipitation, catalyzed by algal photosynthesis, may be an important mechanism for soil P assimilation. -from Authors
Estimates of species density, percentage vegetative cover, biomass, and sawgrass (Cladium jamaicense) height were made in Tall Sawgrass, Medium Sawgrass, and Wet Prairie communities in the SE portion of Water Conservation
Area 3A (3A), the SW portion of Water Conservation Area 3B (3B), the NW portion of Northeast Shark Slough (NSS), and the NE
portion of Everglades National Park (ENP) during dry season and wet season sampling periods in 1986 and 1987. We summarized
the history of water management and hydroperiod manipulation in the study area. Wet Prairie had the deepest water of the three
plant communities studied, while 3A had deepest water and longest hydroperiod of the four areas. Generally, the greatest species
density occurred in NSS, where water was shallowest. Individual sawgrass plants and their basal tussocks were taller in 3A
than in the other three areas, which may make plants in 3A more susceptible to damage by airboats and fire. Cover and biomass
of sawgrass fluctuated more between sampling periods than among management areas, which rendered lower measurements in Tall
Sawgrass in 3B non-significant. Species composition of Wet Prairies, particularly in 3A whereRhynchospora spp. were absent, andNymphaea odorata was dominant, resembled aquatic sloughs. The low species density in the study area may be related to rapid fluctuations in
water levels that could drown slow-growing plants, and to infrequent dry periods that preclude seed germination. Species richness
was low, compared with other Everglades plant community studies. No annual emergent plants were encountered.
Rates of methane emission associated with Florida Typha domingensis Pers. and Typha latifolia L. peaked in the early daylight hours and were two to four times higher than the relatively constant rates observed in the afternoon and night. Factors associated with methane emission peaks were increasing solar illumination which drives pressurized bulk flow ventilation in T. domingensis and T. latifolia, opening of stomata, and decreasing concentrations of methane within plant stems. Cladium jamaicense Crantz, which employs diffusive gas exchange, did not exhibit diurnal variations in methane emission rates although stomatal conductance varied diurnally.Within the Florida Everglades methane emission rates were higher in T. domingensis areas (143±19 mg CH4 m−2 day−1) than in C. jamaicense areas (45±15 mg CH4 m−2 day−1). These elevated rates were related to the higher above ground biomass and production in T. domingensis areas relative to C. jamaicense, which suggests that quantitative differences in plant biomass and production rather than qualitative differences between these plant species may control methane emissions. Methane emission was 2.7±1.4% of net daily ecosystem production (NEP) in a T. domingensis area and 14±5.8% and 3.4±4.2% of NEP in two C. jamaicense areas.
Sawgrass (Cladium jamaicense Crantz) seedlings were subjected to enrichment in a greenhouse both as a means of calibrating the mineral-nutrient status of plants in the field and estimating their response to nutrient enrichment. Available soil nutrients partially predicted seedling response to fertilization. Seedlings responded to sulfur, potassium, and phosphorus (P) fertilization. Small additions of P produced significant increases in dry weight, shoot length, and vegetative reproduction of new plants. Seedling growth response was highly determined by tissue-P levels. Tissue concentrations of P in shoots and roots increased with increasing external concentrations. High levels of P inhibited dry-matter production, shoot elongation, and shoot production. This indicates a potential for adverse consequences resulting from artificial enrichment of Everglades sawgrass marshes. Critical P concentration in seedlings was 0.07%, a value higher than that in sawgrass plants in the field. Experimentally determined critical nutrient levels do not appear to be adequate for diagnosing the nutrient status of plants in the field, unless plants or plant parts of similar maturity are compared.
Container and field experiments, in which Typha latifolia L. and Typha angustifolia L. were cut either above or below the water level, were conducted to determine the physiological basis for reports that the latter treatment was more effective as a control measure. In containers, measurements of oxygen concentrations within the aerenchyma of the rhizome both with an oxygen electrode and by gas chromatography showed that oxygen could diffuse very readily to plant parts growing in an anoxic environment if there was a small amount of leaf or cut plant stem growing above the water level. When all shoots were cut below water, the oxygen in submersed plant parts was rapidly consumed and anaerobic respiration resulted in the production of ethanol. Lactate or elevated malate levels were not found. The below-water biomass decayed rapidly under these conditions and the plants had a much lower regenerative ability than plants cut above water where oxygen continued to reach the roots and rhizomes. In the field, three cuts during the growing season below water were sufficient to kill nearly all the underwater biomass; similar cuts above water reduced the total biomass compared with uncut plants, but much of the underwater biomass remained healthy and able to regenerate.
Estimates of phosphorus (P) and nitrogen (N) gains and losses during annual macrophyte growth, death and 2 years decomposition were made along a gradient of surface water nutrient concentrations in the Florida Everglades.Annual rates of P and N allocation to growing leaves, translocation or leaching from dying leaves, and retention in dead leaves of Cladium jamaicense Crantz and Typha domingensis Pers. were correlated to soluble reactive P and nitrate concentrations in surface water. Rates of each of these processes were higher in T. domingensis than in C. jamaicense, Cladium jamaicense rates increased linearly along the nutrient gradients, but did not fluctuate with yearly variations in soluble reactive P or nitrate concentrations. For T. domingensis, annual rates were strongly correlated with mean annual soluble reactive P and nitrate concentrations during specific sampling years. Responses of C. jamaicense to the nutrient gradient were characteristic of species competitive in an infertile habitat, while responses of T. domingensis were characteristic of species competitive in a fertile habitat.The main effect of P and N enrichment on leaf nutrient flux was to accelerate translocation or leaching from dying tissue, rather than to increase retention in standing dead leaves. Freshly dead leaves retained only slightly greater quantities of P and N under enriched conditions in comparison to background conditions.After 2 years of decomposition, approximately half of the leaf litter mass remained intact. Increasing P and N concentrations in decomposing leaf litter resulted in net uptake or retention of these elements after 2 years despite decreasing litter mass. The total amounts of P and N that were sequestered annually by T. domingensis after processes of leaf production, mortality and 2 years decomposition were lowest under non-enriched conditions and reached a maximum under a moderate level of enrichment.Wetland ecosystems such as the Everglades, which developed under conditions of low nutrient supply, may offer a finite potential for accelerated nutrient retention when the exogenous nutrient supply increases as a result of human activities. However, a plant species such as C. jamaicense, that is adapted to a low-nutrient environment, may have a low nutrient threshold before it loses its competitive capability and its habitat is invaded by a species such as T. domingensis that is better adapted to a high-nutrient environment.
A 6 year (1986–1991) study in Water Conservation Area 2A (WCA2A), a remnant portion of the Florida Everglades, was conducted in which multiple plots within six study sites across a surface water nutrient gradient were monitored for water quality, depth, and sawgrass (Cladium jamaicense Crantz) and cattail (Typha domingensis Pers.) densities. A negative logarithmic relationship was demonstrated between total P concentrations and distance from the nutrient source (levee L-39). Dense cattail stands illustrated by remote sensing in 1987 coincided spatially with high sediment total P concentrations measured in 1990. Cattail density appeared to increase more rapidly than did sawgrass densities during wet years. Cattail decline was greater at nutrient enriched sites than at the low nutrient site during dry years. Drought stimulated sawgrass expansion at nutrient enriched sites, but not at the low nutrient site. Cattail increased at both nutrient enriched and low nutrient sites following fire, yet fire and nutrient enrichment together appeared to stimulate greater increases in cattail density. Multi- and univariate ANOVA revealed significant nutrient effects on plant density during the last 3 years of the study (P<0.05). Stepwise regression analysis suggested that total P loading into WCA2A best explained plant density fluctuations at three of the four sites closest to the levee, while hydrology best explained plant density fluctuations at the site most distant from the levee. Although the single low nutrient site provided an inadequate basis for understanding sawgrass and cattail dynamics under low nutrient conditions, the results of this study support two hypotheses of causal factors leading to the spread of cattail in WCA2A: (1) nutrient enrichment stimulates cattail growth; (2) a prolonged hydroperiod is conducive to cattail proliferation.
Water Management District). 1992. Surface water improvement and management plan for the Everglades. Supporting information document. South Florida Water Management District
- Sfwmd ( South Florida
SFWMD (South Florida Water Management District). 1992.
Surface water improvement and management plan for the
Everglades. Supporting information document. South Florida Water Management District, West Palm Beach, Florida,
USA.
Environmental response of WCA-2A to reduction in regulation schedule and marsh drawdown. Technical Publication 88-2, South Florida Water Management District
- D F Worth
Worth, D. F. 1988. Environmental response of WCA-2A to
reduction in regulation schedule and marsh drawdown.
Technical Publication 88-2, South Florida Water Management District, West Palm Beach, Florida, USA.
Effects of hydrologic regimes on lifetime production and nutrient dynamics of sawgrass. Technical Publication 87-6, South Florida Water Management District Effects of hydrologic regimes on lifetimeproduction and nutrient dynamics of cattail
- L A Toth
- Usa Florida
Toth, L. A. 1987. Effects of hydrologic regimes on lifetime
production and nutrient dynamics of sawgrass. Technical
Publication 87-6, South Florida Water Management District, West Palm Beach, Florida, USA.
. 1988. Effects of hydrologic regimes on lifetimeproduction and nutrient dynamics of cattail. Technical Publication 88-6, South Florida Water Management District,
West Palm Beach, Florida, USA.
Effects of nutrient loadings and hydroperiod alterations on control of cattail expansion, community structure and nutrient retention in the Water Conservation Areas of South Florida
- C J Richardson
- C B Craft
- R G Qualls
- J Stevenson
- P Vaithiyanathan
Richardson, C. J., C. B. Craft, R. G. Qualls, J. Stevenson,
and P. Vaithiyanathan. 1994. Effects of nutrient loadings
and hydroperiod alterations on control of cattail expansion,
community structure and nutrient retention in the Water
Conservation Areas of South Florida. Report submitted to
Everglades Agricultural Area, Environmental Protection
District. Duke Wetland Center Publication 94-08.
Competitive hierarchies and centrifugal organization in plant communities. Pages 265-290 in J. B. Grace and D. Tilman, editors. Perspectives on plant competition Distribution of soil and plant nutrients along a trophic gradient in the Florida Everglades
- P A Keddy
- M S Koch
- K R Reddy
Keddy, P. A. 1990. Competitive hierarchies and centrifugal
organization in plant communities. Pages 265-290 in J. B.
Grace and D. Tilman, editors. Perspectives on plant competition. Academic Press, New York, New York, USA.
Koch, M. S., and K. R. Reddy. 1992. Distribution of soil
and plant nutrients along a trophic gradient in the Florida
Everglades. Soil Science Society of America Journal 56:
1492-1499.
Laing for their many hours of field support in this project
- Chad We Wish To Thank
- Kathy Kennedy
- Jim Pietro
We wish to thank Chad Kennedy, Kathy Pietro, and Jim
Laing for their many hours of field support in this project. In
addition, we wish to thank Ziad Malaeb and Darren Johnson
for statistical advice, and Winnie Park for creating Fig. 1.
The natural features of southern Florida
- J H Davis
Davis, J. H. 1943. The natural features of southern Florida.
Florida Geological Survey, Bulletin Number 25.
Plant responses to flooding of soil
- T T Koslowski
Koslowski, T. T. 1984. Plant responses to flooding of soil.
BioScience 34: 162-167.
Everglades: the ecosystem NUTRIENT AND H Y DlROPERIOD EFFECTS and its restoration
- S S Light
- J W Dineen
Light, S. S., and J. W. Dineen. 1994. Water control in the
Everglades: a historical perspective. Pages 47-84 in S. M.
Davis and J. C. Ogden, editors. Everglades: the ecosystem
NUTRIENT AND H Y DlROPERIOD EFFECTS
and its restoration. St. Lucie Press, Delray Beach, Florida,
USA.
SASISTAT user's guide, version 6 , fourth edition
- Sas
SAS. 1989. SASISTAT user's guide, version 6, fourth edition. SAS Institute, Cary, North Carolina, USA.
Effects of hydrologic regimes on lifetimeproduction and nutrient dynamics of cattail. Technical Publication 88-6, South Florida Water Management District
- L A Toth
- Usa Florida
Toth, L. A. 1987. Effects of hydrologic regimes on lifetime
production and nutrient dynamics of sawgrass. Technical
Publication 87-6, South Florida Water Management District, West Palm Beach, Florida, USA.
. 1988. Effects of hydrologic regimes on lifetimeproduction and nutrient dynamics of cattail. Technical Publication 88-6, South Florida Water Management District,
West Palm Beach, Florida, USA.
Urban, N. H., S. M. Davis, and N. G. Aumen. 1993. Fluctuations in sawgrass and cattail densities in Everglades Water Conservation Area 2A under varying nutrient, hydrologic and fire regimes. Aquatic Botany 46:203-223.