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WETLANDS AND BIODIVERSITY
... Storage of this water occurs in the channel, the basin and ground water table, which coexist with the hydric soils and create specific conditions suitable for growth and establishment of hydrophytic vegetation at least periodically (Denny, 1995;Schuyt and Brander, 2004). The hydrophytic vegetation refers to plants adapted to wet conditions and areas that are covered by water for at least part of the growing season (Bacon, 1997). A soil is considered hydric if it has been flooded of saturated with water long enough to become anaerobic. ...
... They are regarded as the most popular biotic assemblage for use in wetland bioassessment worldwide, since their spatial distribution in the landscape results from a multitude of factors, including substrate type, water chemistry, and hydroperiod, as well as climatic conditions (Bedford, 1996;Reiss, 2006). The macrophyte assemblage plays a vital role in supporting the structure and function of wetlands by providing food and habitat for other assemblages including algae, macroinvertebrates, fish, amphibians, reptiles, birds, and mammals (Bacon, 1997;Cronk and Fennessy, 2001). ...
... Posición geográfica ( encuentran reguladas por estos ciclos (Bacon, 1996). Los troncos hundidos se extrajeron del agua en forma manual y rápida para evitar el escape de organismos (O´Connor, 1991;Florido et al., 2000). ...
The dynamics and structure of aquatic communities are affected by the habitat complexity as diversity and abundance increase with the availability of structured habitats such as coarse woody debris that provides sites used for refuge, feeding and reproduction. Manual sampling of the fauna associated with this habitat was carried out twice during the season of maximum floods and once during minimum flooding, in 18 lagoons of Pantanos de Centla with coarse woody debris. The 1 228 crustaceans collected belong to 4 orders, 11 families, 11 genera and 13 species, among which malacostracans dominated with 12 species. The 13 species of crustaceans reported here represented 17% of the total carcinofauna recorded in the freshwater ecosystems of Tabasco. The amphipod Hyalella azteca was the numerically dominant species. The distribution of Balanus improvisus, Uhlorchestia ulheri, Platychirograpsus spectabilis, Armases cinereum and Goniopsis cruentata was restricted mainly to the area of marine influence. Moreover, B. improvisus and Sphaeroma terebrans were the only 2 sessile and wood-boring species. Coarse woody debris is also an alternative habitat for the other 11 species.
... Los troncos hundidos se muestrearon en 3 ocasiones; 2 en la temporada de máxima inundación (noviembre y diciembre, 2000 y 2001) y 1 en la de mínima inundación (mayo y junio, 2001), para cubrir los extremos del ciclo de inundación registrados en el área, ya que la dinámica y la organización de las comunidades acuáticas se encuentran reguladas por estos ciclos (Bacon, 1996). Los troncos hundidos se extrajeron del agua en forma manual y rápida para evitar el escape de organismos (O´Connor, 1991;Florido et al., 2000). ...
The dynamics and structure of aquatic communities are affected by the habitat complexity as diversity and abundance increase with the availability of structured habitats such as coarse woody debris that provides sites used for refuge, feeding and reproduction. Manual sampling of the fauna associated with this habitat was carried out twice during the season of maximum floods and once during minimum flooding, in 18 lagoons of Pantanos de Centla with coarse woody debris. The 1 228 crustaceans collected belong to 4 orders, 11 families, 11 genera and 13 species, among which malacostracans dominated with 12 species. The 13 species of crustaceans reported here represented 17% of the total carcinofauna recorded in the freshwater ecosystems of Tabasco. The amphipod Hyalella azteca was the numerically dominant species. The distribution of Balanus improvisus, Uhlorchestia ulheri, Platychirograpsus spectabilis, Armases cinereum and Goniopsis cruentata was restricted mainly to the area of marine influence. Moreover, B. improvisus and Sphaeroma terebrans were the only 2 sessile and woodboring species. Coarse woody debris is also an alternative habitat for the other 11 species.
... Most of its water derives from a series of rivers in the central mountain range. The swamp is able to provide for a diverse faunal biodiversity because of the various distinct types of vegetation ranging from tropical forest, swamp forest, palm swamp forest, mangrove areas, marshland, and open waters (Bacon, 1996). It is listed as a Wetland of International Importance under the Ramsar Convention as of 1992 and in 2006 it became an Environmental Sensitive Area under the Environmental Management Act of Trinidad and Tobago. ...
This paper develops and tests the application of a Livelihood Vulnerability Index (LVI) for agricultural and natural resource-dependent communities in developing countries. The index is applied in a comparative study of two wetland communities in Trinidad and Tobago, a country that is expected to bear some of the most severe impacts of climate change. Our application of the LVI entailed a series of critical focus group discussions involving local community representatives, government officials and researchers. Researchers collected household data for eight types of assets, which were aggregated into composite LVIs and differential vulnerabilities of the two communities being compared. The results of the analysis suggest that one of the communities, “Nariva”, was more vulnerable than the other, “Caroni”, particularly in relation to socio-demographics, health and water security, natural disaster and climate variability. Caroni on the other hand was more vulnerable in relation to other LVI indicators with the exception of food security. On questions of gender, the study found that female-headed households were marginally more vulnerable than male-headed households. Overall, the study suggests that the livelihood vulnerability index can be broadly applied in comparable settings in small-island developing states and other developing countries. In so doing, it provides a reliable methodology that can be used to assess community vulnerability and design management plans in areas with limited resources and access to reliable data.
Embracing energy efficiency (EE) and renewable energy (RE) is essential for improving environmental quality. This research investigates the asymmetric impacts of EE, RE, and other factors on CO2 emissions in BRICS (i.e., Brazil, Russia, India, China, and South Africa) countries from 1990 to 2014. In contrast to previous studies, the present study considers EE as a major cause of CO2 emissions in BRICS countries. By using the new hidden panel cointegration and nonlinear panel autoregressive distributive lag model, this study is the first of its kind that unfolds the asymmetric links among EE, RE, and CO2 emissions. Findings clearly explain that the impact of the selected variables on CO2 emissions is asymmetric, and both EE and RE help to lower CO2 emissions in BRICS countries. In the long run, positive shocks in EE and RE can significantly mitigate CO2 emissions in BRICS economies. In particular, a 1% fluctuation in the positive sum of EE reduces CO2 emissions by 0.783% in the long run. On the other hand, a 1% fluctuation in the positive component of RE reduces CO2 emissions by 0.733%. Moreover, individual country estimates suggest the heterogeneous effects among BRICS countries. Based on the empirical findings, policymakers should consider the asymmetric behavior of the EE, RE, and economic growth while formulating, energy, environment, and growth policies of BRICS countries.
Graphical abstract
A rapidly growing human population and the extirpation of numerous species make modern wetlands among the most threatened of ecosystems. One of the endangered wetland plants in central and eastern Europe is Betula humilis. B. humilis forms comparably abundant populations on both well-preserved and drained fens; thus, we aimed in this paper to investigate the relationships between habitat quality parameters (e.g. concentrations of calcium and magnesium, groundwater levels, pH and conductivity) and genetic diversity in 12 populations of B. humilis from Poland, Belarus and Latvia. For the purposes of this study, alcohol dehydrogenase (ADH) gene sequences and nuclear microsatellites were chosen as molecular markers. Analyses revealed that only the Ca2+ concentration was significantly negative relative to the observed heterozygosity of microsatellites, which suggests that calcium access is the only factor influencing genetic variation at B. humilis localities. No genetic differentiation was detected between populations occupying wet and dry habitats in different parts of the species range. A minimum spanning tree based on ADH gene haplotypes appears to confirm the B. humilis population history previously inferred from analyses of nuclear microsatellites and chloroplast markers.
Abstract
A demonstration project was set up to create two small papyrus wetlands in villages on the shores of Lake Victoria near Rubondo Island National Park, aimed at helping the community to replenish the fish stock in the lake and to improve socio-economics. The wetlands were constructed by using locally available means and they are owned and successfully managed by the villages to support community-based activities. We describe the approach, methodology and design of these plots. 2 years after the wetlands were created, the above-ground papyrus biomass was found to be comparable with that of pristine papyrus wetlands at Mlaga Bay in Rubondo Island National Park. Light trap data shows increased fish around the area. This correlated well with the results of questionnaire survey from the community around the created wetland. Our study shows that the degraded wetlands around Lake Victoria can be recreated by using locally available means, to restore most of the vital functions of those wetlands as they were before destruction, and improve the socio-economics of the local communities.
Keywords
Lake Victoria � Papyrus wetlands �Wetlands creation � Eutrophication � Tilapia fish �Socio-economics
Daytime sampling of mangrove and seagrass (Halophila/Halodule community) habitats every 7 wk at Alligator Creek, Queensland, Australia, over a period of 13 mo (February 1985–February 1986) using two types of seine net, revealed distinct mangrove and seagrass fish and crustacean faunas. Total abundance of fish and relative abundance of small and large fish also varied between habitats and seasonally. Post-larval, juvenile and small adult fish captured with a small seine-net (3 mm mesh) were significantly more abundant (4 to 10 times) in the mangrove habitat throughout the 13 mo of sampling. Mangrove fish abundance showed significant seasonality, greatest catches being recorded in the warm, wet-season months of the year. Relative abundances of larger fish (captured in a seine net with 18 mm mesh) in the two habitats varied throughout the year, but did not show a seasonal pattern. At the same site, small crustaceans were significantly more abundant in the mangroves in all but one dryseason sample. Similar comparisons for three riverine sites, sampled less frequently, in the dry and wet seasons of 1985 and 1986, respectively, showed that in general mangrove habitats had significantly more fish per sample, although the relative abundance of fish in mangroves and other habitats changed with season. Crustacean catches showed a similar pattern, except that densities among sites changed with season. Fish and crustacean abundance in mangroves varied among sites, indicating that estuaries differ in their nursery-ground value. The juveniles of two commercially important penaeid prawn species (Penaeus merguiensis and Metapenaeus ensis) were amongst the top three species of crustaceans captured in the study, and both were significantly more abundant in the mangrove habitat. By contrast, mangroves could not be considered an important nursery for juveniles of commercially important fish species in northern Australia. However, based on comparisons of fish catches in other regions, the results of the present study indicate the importance of mangroves as nursery sites for commercially exploited fish stocks elsewhere in South-East Asia.
The productivity and composition of two study sites in a southern Louisiana freshwater swamp were studied from October 1973 to November 1974. Net productivity was determined from measurements of litter-fall, stem growth of woody species, and harvest samples of annual herbaceous understory. Annual stem growth was calculated from biomass estimates on two different dates. The annual increase in stem biomass was 800 g dry wt/m² for a bottomland hardwood site (BLH) and 500 g dry wt/m² for a baldcypress-water tupelo site (CT). Litter-fall was 574 g dry wt/m²/yr for BLH and 620 g dry wt/m²/yr for CT. Harvest samples within the two plots yielded 200 g dry wt/m² and 20 g dry wt/m² for BLH and CT, respectively. Minimum net primary production was calculated as the sum of the three: 1574 g dry wt/m²/ yr for BLH and 1140 g dry wt/m²/yr for CT. Maximum estimates of herbaceous production and insect consumption were made by using values from the literature. Estimated total net primary productivity was 1733 g dry wt/m²/yr for BLH and 1516 g dry wt/m²/yr for CT. Tree composition was determined by the point-centered quarter method. Relative frequency, relative density, absolute density, relative dominance, and importance value (IV) were calculated for the tree species along each transect. In the bottomland hardwood area many woody species exist with Acer rubrum var. drummondii (IV = 23.9) and Nyssa aquatica (IV = 18.4) the most dominant. In the baldcypress-water tupelo area, fewer woody species exist and Taxodium distichum (IV = 39.2) and N. aquatica (IV = 37.6) dominated. Comparison of productivity data from several southeastern swamps indicate that flowing water regimes tend to result in the highest swamp forest productivity.
In the course of the last century a considerable amount of scientific work has been carried out in the Cayman Islands. The results of this (outlined in Chapter 1) are widely distributed in unpublished reports, university theses, various scientific publications and books, many of these sources being difficult to find and some now unobtainable.
The purpose of this book, therefore, is to bring all this scattered information together and to present a coherent account of the biogeography and ecology of the Islands, as an easily available reference source and as a foundation on which future work can be based.
This chapter discusses the ecology of seagrass beds in the coastal zone of Puerto Rico. It provides an overview of species composition, distribution, relative abundance, and primary production with an emphasis on turtle grass. Seagrasses form vast meadows over shallow unconsolidated sediments on the continental and island shelves of the world. They modify the physical, chemical, and geological properties of coastal areas. Seagrasses provide nutrients, primary energy, and habitats that sustain the coastal fishery resources. They provide foraging grounds for some endangered marine species and form one of the biologically most diversified biotopes. The depth limits of seagrasses depend on variables like substrate type, turbidity, and grazing pressure. Turbidity determines the maximal depth of turtle grass. Male and female turtle grass flowers are found from March through June in the intertidal and shallow subtidal zone. The percentage of shoots with reproductive structures varies from 4 to 54% during May. Turtle grass beds exposed to high wave energy, sand burial, poor water quality, and heated effluents do not reproduce sexually.
Phytoplankton gross primary production (14 C method) in the shallow, eutrophic Danish Lake Arresø in 1973 was 980 g C m-2. Calculated net primary production was near zero. Macrophyte net primary production was measured by harvesting the maximum biomass, and above ground values were between 420 and 1325 g ash free dry wt m-2, while below ground values were between 2480 and 8570 g ash free dry wt m-2. The reed swamps were mapped on aerial photographs, and the composition of the macrophyte vegetation was determined. A comparison of macrophyte vegetation in 1944 and 1972 showed a reduction in species diversity, especially of submerged species. The seasonal variations in physical and chemical data indicated strong eutrophication in Arresø. /// Первиеная валовая продукция фитопланктона определялась с помошью 14 C в мелкововодном эутрофном озере Аррезö /Дания/. B 1973 г̣ она составляла 980 г C m-2. Рассчитанная чистая первичная продукция к 0. Чистая первичная продукция Макрофитов измерялась по урожаю макасимальной биомассы, и велеичина надземной массы колебалась между 420 и 1325 г беззольного сухого в-ва/ m-2, а величины подземной массы - 2480-5870 г беззольного сухого в-ва m-2. Тростниковые болота картировались аэрофотосьемкой, и определялся состав макрофитоной растительности. Сравнения макрофитной растительности в 1944 и 1972 гг. показали сннжение видового разнообразия, особенно погруженных видов. Сезонные колебания физических и химических данных свидетельчтвуют о сильной эутрификации в Аррезö.
A literature review is made of the conomic and ecological values with man's uses of mangrove swamps. Mangrove forests are among the most productive estuarine ecosystems. The mangrove forest is of considerable importance, not only as a source of firewood, charcoal, timber, and tannin, but also as a shoreline stablilizer. A recent development in mangrove utilization has been production of high-alpha pulps for the manufacturing of rayon, cellophane, lacquers, cellulose acetate, and other cellulose derivatives. - from Selected Water Resources Abstracts
Production and mortality of six marsh macrophytes were measured in Louisiana, USA using phenometric methods. The Williams-Murdoch technique estimates annual production from measurements of individual culm height, mass, growth, and longevity. Annual mortality was estimated from bimonthly field measurements of culm height, mass, and death rate as a function of height, and density. Annual production estimates averaged 1.8 times higher than annual mortality estimates although in a steady-state system the rates should be about equal. A probable and correctable reason for the discrepancy is discussed. These estimates are higher than those calculated from Smalley's method but lower than those obtained from the Wiegert-Evans paired-plot technique. The validity of various techniques are applied to wetlands is discussed.
The National List of Plant Species That Occur in Wetlands: 1988 (National List) represents the combined efforts of many biologists over the last decade to define the wetland flora of the United States. The National List has undergone a number of revisions resulting from intensive review by regional ecologists. National, regional and State lists are being distributed to provide users with the most current information. We welcome and encourage modification and improvement of the National List. Refinement of the National List will occur continually, reflecting increased knowledge in Indicator assignments, taxonomy, and geographic distribution. We anticipate that further refinement of the National List will lead to additional infra-specific and subregional Indicator assignments. Review documents and procedures are included with the National List to aid and encourage additional review. The U.S. Fish and Wildlife Service initially developed the National List in order to provide an appendix to the Classification of Wetlands and Deepwater Habitats of the United States (Cowardin et al. 1979) to assist in the field identification of wetlands. Plant species that occur in wetlands as used in the National List are defined as species that have demonstrated an ability (presumably because of morphological and/er physiological adaptations and/or reproductive strategies) to achieve maturity and reproduce in an environment where all or portions of the soil within the root zone become, periodically or continuously, saturated or inundated during the growing season (adapted from Huffman 1981). The development of the National List changed- significantly when a cooperative review effort was established by the major Federal agencies involved in wetland identification and management. The utility of the National List goes far beyond a simple catalog of wetland plants. The Fish and. Wildlife Service, in cooperation with North Carolina State University, has produced a weighted average procedure for using the wetland Indicator assignments of individual species to assist in determining the probability that a community is a wetland, (Wentworth and Johnson 1986). This procedure is used by the 'Soil Conservation Service to aid in the determination of wetlands included under the conservation provisions of the Food Security Act of 1985. The Fish and Wildlife Service, Army Corps of Engineers, Environmental Protection Agency, and Soil Conservation Service use the National List to aid in identifying wetlands falling under their various wetland program responsibilities.
Wetlands are major occupiers of coastal areas in the Caribbean. They have been impacted seriously by tourism in many islands, through drainage and filling for resorts and biting insect control. Some island wetlands contribute to tourism and recreation, both generally and for special interest visitors. This article reviews wetland losses. Case studies in Jamaica and Trinidad are used to evaluate the potential use of wetlands for diversification of the tourism industry. A methodology is presented for evaluating potential visitor use of wetlands in relation to regional needs in conservation. This methodology selects ecological and socioeconomic criteria in relation to national priorities for wetland conservation, before consideration of site potential for visitor use.RésuméL'utilisation des marécages pour le tourisme dans les îles des Caraïbes. Une grande partie des régions côtières des Caraïbes se forme de marécages. Dans beaucoup d'îles, le tourisme a eu un impact considérable sur les marécages, à cause du drainage et du remplissage pour la construction des stations balnéaires et pour l'élimination des insectes piqueurs. Quelques marécages des îles contribuent au tourisme et à la récréation, soit d'une façon générale soit pour les visiteurs qui s'y intéressent en particulier. Le présent article examine la perte des marécages. On discute des cas particuliers à la Jamaïque et à la Trinité pour évaluer la possibilité d'utiliser des marécages pour la diversification de l'industrie touristique. On présente une méthodologie pour évaluer l'utilisation éventuelle des marécages par des visiteurs vis-à-vis des besoins régionaux pour la défense de l'environment. Cette méthodologie choisit des critères écologiques et sociologiques par rapport aux priorités nationales pour la protection des marécages avant de considérer les attraits de l'endroit pour l'usage touristique.
The open characteristics of freshwater riverine marshes result in a continual subsidy and withdrawal of nutrients, with the specific patterns within any wetland being dependent on seasonal hydrological fluctuations and biological activity. One of the key features of the marsh separating it from terrestrial ecosystems is its inundated and anaerobic soils which show significant (P > 0.01) seasonal variations in available P and K and exchangeable Ca and Mg. Based primarily on investigations in Wisconsin, the role of emergent macrophytes within the marsh nutrient cycle is described. Concentrations of N, P, K, Ca, and Mg are shown to follow predictable trends over the growing season. However, the accumulation of these elements in the below and aboveground structures is shown to yield a more complete picture of the functional role of emergent macrophytes. Regression analyses showed nutrient uptake by the macrophytes was significantly correlated (r/sup 2/ = 0.98, P > 0.01) to total soil N and available P. For the most part, significant correlations were not shown for the other elements and is explained based upon their mobility and the possibility of luxury uptake. Models of the flow of nutrients in a Scirpus fluviatilis stand are depicted.
Productivity studies were carried out from September, 1985 to August, 1987 in two mangrove stands, i.e. estuarine and island fringing, in Dutch bay, a lagoon situated on the northwestern coast of Sri Lanka. Net above-ground primary productivity was measured by monitoring litterfall and above-ground biomass increment. The average annual rate of litterfall in the estuarine and island-fringing mangrove stands are 588.14 g m–2 (approximately 6 t ha–1) and 407.33 g m–2 (approximately 4 t ha–1) respectively. The average annual rates of above ground woody growth are 614.74 g m–2 (approximately 6 t ha–1) in the estuarine stands and 286.8 g m–2 (approximately 3 t ha–1) in the island-fringing mangrove stands. Hence estuarine mangrove stands record a higher annual rate of above-ground net primary production (NPP; 1207.88 g m–2 or approximately 12 t ha–1) than the fringing mangrove stands (694.22 g m–2); approximately 7 t ha–1). The annual rate of NPP in the water front zones of the stands (1300.47 g m–2 in the estuarine stands and 874.56 g m–2 in the fringing stands) are greater than those in the back-mangrove zones (115.28 g m–2 in the estuarine stands and 513.88 g m–2 in the island-fringing stands). These variations may be attributed to the differences in tidal flushing and influence of freshwater in the two localities.
This classification, to be used in a new inventory of wetlands and deepwater habitats of the United States, is intended to describe ecological taxa, arrange them in a system useful to resource managers, furnish units for mapping, and provide uniformity of concepts and terms.Wetlands are defined by plants (hydrophytes), soils (hydric soils), and frequency of flooding. Ecologically related areas of deep water, traditionally not considered wetlands, are included in the classification as deepwater habitats. Systems form the highest level of the classification hierarchy; five are defined—Marine, Estuarine, Riverine, Lacustrine, and Palustrine. Marine and Estuarine Systems each have two Subsystems, Subtidal and Intertidal; the Riverine System has four Subsystems, Tidal, Lower Perennial, Upper Perennial, and Intermittent; the Lacustrine has two, Littoral and Limnetic; and the Palustrine has no Subsystems.
Freshwater foodchains of Caribbean island wetlands
- P R Bacon
• Bacon, P. R. 1988. Freshwater foodchains of Caribbean island wetlands. Acta
Cientifica, 2(2-3); 74-93.
- P R Bacon
- J S Kenny
- M E Alkins
• Bacon, P.R., Kenny, J.S., and Alkins, M.E. 1979. Studies on the Biological
Resources of Nariva Swamp, Trinidad. Occasional Papers No. 4, Zoology
Department, University of the West Indies, Trinidad.
Research priorities in fisheries management as a tool for wetlands conservation and rural development in Africa
- G M Bernacsek
• Bernacsek, G.M. 1992. Research priorities in fisheries management as a tool for
wetlands conservation and rural development in Africa. In Conservation and
Development: The Sustainable Use of Wetland Resources. IUCN, Switzerland; 131-144.
Mangroves of the Wider Caribbean: Towards Sustainable Management. Caribbean Conservation Association, UNEP and the Panos Institute
- R Bossi
- G Cintron
• Bossi, R. and Cintron, G. 1990. Mangroves of the Wider Caribbean: Towards
Sustainable Management. Caribbean Conservation Association, UNEP and the
Panos Institute.
- M Jones
• Jones, M. 1983. Papyrus: A new fuel for the Third World. New Scientist, 17
August; 418-421.
Forested Wetlands. Ecosystems of the World
- A E Lugo
- M Brinson
- S Brown
• Lugo, A.E., Brinson, M. and Brown, S. 1990. Forested Wetlands. Ecosystems of the
World, 15.
Waterbird hunting and management in S.E. Asia
- D Parish
- J R Howes
• Parish, D. and Howes, J.R. 1990. Waterbird hunting and management in S.E. Asia.
In: Matthews, G.V.T. (ed), Managing Waterfowl Populations. IWRB Special
Publication No. 12; 128-131.