Article

The Effect of Prosopis juliflora (Fabaceae) on the Physical and Chemical Properties of Coastal Dune Soil in Western Mexico

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Vargas-Lomeln, J.G.; Macas-Rodrguez, M..; Zaraza-Villaseor, P.; Rodrguez-Zaragoza, F.A.; Neri-Luna, C., and Albuquerque, F., 2023. The effect of Prosopis juliflora (Fabaceae) on the physical and chemical properties of coastal dune soil in western Mexico. Journal of Coastal Research, 39(1), 6372. Charlotte (North Carolina), ISSN 0749-0208. Prosopis juliflora (Fabaceae) is a dominant legume and potential ecosystem engineer in the dunes of Jalisco, western Mexico. The objective of the present study was to evaluate how P. juliflora modifies soil physical and chemical properties in three coastal dunes that belong to different watersheds. To determine the physical properties of the three sites, soil samples were taken inside the canopy of five P. juliflora trees and five soil samples were taken outside their canopies. The same trees and soil positions regarding the canopy of P. juliflora were considered to determine the chemical properties, but the samples were taken at two different depths. A multidimensional and permutational analysis of variance (PERMANOVA) was performed to evaluate differences in the physical properties among the sites and between the sampling positions relative to the canopy of P. juliflora. This PERMANOVA also evaluated differences among sites, sample depths, and the positions of the samples relative to the P. juliflora canopy. A test of homogeneity of dispersions was performed to determine the data dispersion type, whereas a similarity percentage analysis identified which variables contributed most to the observed differences. A principal coordinate analysis was performed to visualize the differences in the model. The results demonstrated that P. juliflora modified the soil physical properties, specifically the real density, total porosity percentage, and percentages of silt and clay. The soil physical properties also varied significantly among the three sites. In addition, P. juliflora modified the soil chemical properties, increasing the electrical conductivity, pH, and total nitrogen, iron, and available phosphorus content. The results show significant differences between the two soil depths, as well as among sites. Ultimately, this study contributes to understanding of the implications of soil property modifications by plants in coastal dunes, which will give guidelines for managing and conserving these ecosystems.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

ResearchGate has not been able to resolve any citations for this publication.
Article
Full-text available
Understanding the effects of silvicultural practices including single-tree selection on soil properties is essential for forest management in temperate broadleaved beech forests. Changes in physico-chemical and biological soil properties in 15 harvest-created gaps under single-tree selection and the adjacent closed canopies, with five replications for each, were studied 6 years after gap creation in an oriental beech (Fagus orientalis L.) stand of the Hyrcanian forest. Gaps were classified into three size classes: small (85-130 m2), medium (131-175 m2) and large (176-300 m2). Soil cores were collected at the center and at the edge of gaps, and under the adjacent closed canopy. Results indicated that gap size significantly affected soil texture and bulk density, whereas soil organic carbon (SOC), total nitrogen and pH showed a significant gradient from the center to the edge of gap independently form their size. SOC and total nitrogen at the center of gaps were also significantly lower than closed-canopy, in particular for the medium-gap; contrastingly, the bulk density with the highest mean value was found at the center of the large-gap. Gap size had no significant influence on soil microbial biomass. These results highlighted that similar conditions in terms of many soil properties were still present among gaps and adjacent closed-canopy stands six years after logging, though canopy openness triggered a reduction in carbon and nitrogen availability along with the related microbial activity at the center of gaps, independently from their size. Therefore, if aimed at preserving an uneven aged structure along with soil quality in temperate broadleaved deciduous forest as the oriental beech stands in the Hyrcanian region, single-tree selection practice for harvesting trees can be recommended as sustainable forest management type.
Article
Full-text available
In tropical regions, climate conditions favor fast decomposition of soil organic matter (SOM), releasing into the soil organic composts in solid, liquid, and gaseous forms with variable compositions. Dissolved organic matter (DOM), a complex mixture of thousands of organic compounds, is only a small fraction of the decomposition products; however, it is highly mobile and reactive to the soil. Therefore, DOM play a key role in soil aggregation (formation of organometallic complexes), energy source for microorganisms, as well as C storage, cycling, and provision of plant-available nutrients. DOM multifunctionality to sustain soil functions and important ecosystem services have raised global scientific interest in studies on DOM fractions. However, previous studies were conducted predominantly under temperate soil conditions in natural ecosystems. Therefore, there is paucity of information on tropical soil conditions under agricultural systems, where DOM turnover is intensified by management practices. This review synthesized information in the literature to identify and discuss the main sources, transformations , and future of DOM in soils. We also discussed the importance of this fraction in C cycling and other soil properties and processes, emphasizing agricultural systems in tropical soils. Gaps and opportunities were identified to guide future studies on DOM in tropical soils.
Article
Full-text available
An information system was obtained consisting of monthly, seasonal and annual raster images, corresponding to climatic and agroclimatic parameters for the Mexico-Central America region. This achievement involved the creation of daily and monthly climatic data bases for the period 1961-2010, review of information to eliminate aberrant data and estimate lost data; geographic interpolation using the Anusplin method to generate monthly raster images of basic climatic variables (maximum temperature, minimum temperature, precipitation), map algebra and spatial analysis to generate agroclimatic parameters derived from the basic climatic variables; use of climate information from a network of automated agrometeorological stations to estimate parameters adjusted to the reference method; estimation of agroclimatic parameters through indirect methods and use of information derived from data assimilation models for the generation of complementary agroclimatic parameters. The results showed the obtaining of an information system composed of raster images that represent the average value for the 1961-2010 period of 144 monthly variables (maximum temperature Tx, minimum temperature Ti, average temperature Tm, thermal range RT, thermal sum ST, cumulative development day degrees GDD, photoperiod F, precipitation P, potential evapotranspiration ETP, humidity index IH, solar radiation Rs and relative humidity RH); 41 seasonal variables corresponding to the growing season (previous variables plus duration of growing season DEC, and number of wet months MH= P≥ ETP); 13 annual variables (same monthly variables plus number of wet months) and the variable altitude. The raster images are referenced in the WGS system, can be used in any geographic information system (SIG) and have a resolution of 30” arc. The system is potentially useful to characterize the variation of agroclimatic conditions in Mexico and Central America.
Article
Full-text available
Tropical forests are characterized by high biodiversity and aboveground biomass growing on strongly weathered soils. However, the distribution of plant species and soils are highly variable even within a tropical region. This paper reviews existing and novel knowledge on soil genesis, plant and microbial physiology, and biogeochemistry. Typically, forests in Southeast Asia are dominated by dipterocarps growing on acidic Ultisols from relatively young parent material. In the Neotropics and Africa, forests contain abundant legume trees growing on Oxisols developed in the older parent materials on stable continental shields. In Southeast Asia, the removal of base cations from the surface soil due to leaching and uptake by dipterocarp trees result in intensive acidification and accumulation of exchangeable Al³⁺, which is toxic to most plants. Nutrient mining by ectomycorrhizal fungi and efficient allocation within tree organs can supply phosphorus (P) for reproduction (e.g., mast fruiting) even on P-limited soils. In the Neotropics and Africa, nitrogen (N) fixation by legume trees can ameliorate N or P limitation but excess N can promote acidification through nitrification. Biological weathering [e.g., plant silicon (Si) cycling] and leaching can lead to loss of Si from soil. The resulting accumulation of Al and Fe oxides in Oxisols that can reduce P solubility through sorption and lead to limitation of P relative to N. Thus, geographical variation in geology and plant species drives patterns of soil weathering and niche differentiation at the global scale in tropical forests.
Article
Full-text available
Quantitative studies about vegetation in Mexico have focused on tropical and cloud mountain forests, compared to which those of temperate forests are relatively scarce. Many have described light as a directing force in the distribution of resources among species; however, some such as soil nutriments have received less attention. In this paper is described the community structure of a mild-weather forest community along an altitudinal gradient of Tequila Volcano, in the state of Jalisco; the analysis was made according the α and β diversity, as well as soil variables relationships by ordination techniques, that explained 97 % of total variation; the most important variables were altitude, clay content, potassium, pH, electric conductivity, nitrites, sand, nitrogen, phosphorous and calcium. Tree richness showed a unimodal response in regard to altitude, with a maximum value between 2 000 a 2 350 m asl. Finally, the greatest species turnover rate occurs between the places with the highest altitude and those of the lowest (1.0). In Tequila Volcano there is a niche differentiation among species, which is due to the distribution of edaphic resources along the altitude gradient, which is acknowledged as the major mechanism that keeps the tree diversity in the temperate portion of the study area.
Article
Full-text available
Prosopis juliflora is one of the suitable tree species used as vegetation cover for sand dunes fixation. The objectives of this study were to determine the effect of P. juliflora afforestation and its canopy coverage classes on soil carbon (C) stock and nutrient status in sand dunes after 22 years since afforestation. We hypothesized that increasing the canopy coverage would result in higher soil C stocks and nutrient content. We selected two 10-ha afforested sand dunes with 25-50% and more than 75% canopy coverage, respectively, and a 10-ha non-afforested dune (control). At each site, 15 soil samples were taken at two depths (0-5 cm and 5-50 cm). The results indicated a strong increase in the topsoil C stock (from 0.54 to 4.49 tC ha-1 in control and afforested sites, respectively), while a lower change in subsoil C stock was detected (3.0 and 4.6 tC ha-1 in control and afforested sites, respectively). Although, different canopy classes resulted in no significant differences in soil C stock, significant differences were observed for all the soil physico-chemical properties that were studied.
Article
Full-text available
Nurse plants promote establishment of other plant species by buffering climate extremes and improving soil properties. Soil biota plays an important role, but an analysis to disentangle the effects of soil microorganisms, soil properties and microclimate on facilitation is lacking. In three microhabitats (gaps, small and large Retama shrubs), we placed six microcosms with sterilized soil, two per soil origin (i.e. from each microhabitat). One in every pair received an alive, and the other a sterile, inoculum from its own soil. Seeds of annual plants were sown into the microcosms. Germination, survival and biomass were monitored. Soil bacterial communities were characterized by pyrosequencing. Germination in living Retama inoculum was nearly double that of germination in sterile inoculum. Germination was greater under Retama canopies than in gaps. Biomass was up to three times higher in nurse than in gap soils. Soil microorganisms, soil properties and microclimate showed a range of positive to negative effects on understory plants depending on species identity and life stage. Nurse soil microorganisms promoted germination, but the effect was smaller than the positive effects of soil properties and microclimate under nurses. Nurse below‐ground environment (soil properties and microorganisms) promoted plant growth and survival more than nurse microhabitat.
Article
Full-text available
Plant facilitative interactions enhance co-occurrence between distant relatives, partly due to limited overlap in resource requirements. We propose a different mechanism for the coexistence of distant relatives based on positive interactions of nutrient sharing. Nutrients move between plants following source-sink gradients driven by plant traits that allow these gradients to establish. Specifically, nitrogen (N) concentration gradients can arise from variation in leaf N content across plants species. As many ecologically relevant traits, we hypothesize that leaf N content is phylogenetically conserved and can result in N gradients promoting N transfer among distant relatives. In a Mexican desert community governed by facilitation, we labelled nurse plants (Mimosa luisiana) with (15) N and measured its transfer to 14 other species in the community, spanning the range of phylogenetic distances to the nurse plant. Nurses established steeper N source-sink gradients with distant relatives, increasing (15) N transfer towards these species. Nutrient sharing may provide long-term benefits to facilitated plants and may be an overlooked mechanism maintaining coexistence and increasing the phylogenetic diversity of plant communities. This article is protected by copyright. All rights reserved.
Article
Full-text available
Hanlon, L.M.; Abbott, L.K., and Kennedy, D.M., 2016. Coastal mycology and invasive species: Boundary conditions for arbuscular mycorrhizal (AM) fungi in incipient sand dunes. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R. 0749-0208. Arbuscular mycorrhizal (AM) fungi are ubiquitous in soil, and are associated with some 90% of terrestrial vascular plants, aiding plants to access water and nutrients the plant roots alone cannot, in exchange for photosynthates from their host. AM fungi were first found in the dune system in the 1960s, and many of the described species have been found in dune ecosystems, where they form symbiotic associations with psammophilic plants including dune grasses. The ephemeral environment of incipient sand dunes prevents long-term colonization by plants, and little research has been undertaken to examine the contribution of AM fungi to plant survival in the disturbed environment of incipient sand dunes, or what role, if any, they play in exotic plant species outcompeting native species. A first step to understanding these roles is to examine the edaphic and biological conditions of incipient dunes. Our findings quantify the boundary conditions that surround and support AM fungi and their host plant roots in incipient sand dunes on the southern coast of Victoria, and include the chemical and geomorphological characterizations of the dunes studied. We found the nutrient levels (TOC, P, and N) to be low, in contrast to the higher levels of N found on the Atlantic coast, and pH levels such that Al would be toxic for the majority of plants, whilst Fe is limited. Additionally, we found that the incipient dune sand was not saline, and that chemical characteristics between the toe and the crest of the incipient dune did not differ greatly.
Article
Full-text available
The presence of vegetation strongly influences ecosystem function by controlling the distribution and transformation of nutrients across the landscape. The magnitude of vegetation effects on soil chemistry is largely dependent on the plant species and the background soil chemical properties of the site, but has not been well quantified along vegetation transects in the Great Basin. We studied the effects of plant canopy cover on soil chemistry within five different ecological zones, subalpine, montane, pinyon–juniper, sage/Mojave transition, and desert shrub, in the Great Basin of Nevada all with similar underlying geology. Although plant species differed in their effects on soil chemistry, the desert shrubs Sarcobatus vermiculatus, Atriplex spp., Coleogyne ramosissima, and Larrea tridentata typically exerted the most influence on soil chemistry, especially amounts of K+ and total nitrogen, beneath their canopies. However, the extent to which vegetation affected soil nutrient status in any given location was not only highly dependent on the species present, and presumably the nutrient requirements and cycling patterns of the plant species, but also on the background soil characteristics (e.g., parent material, weathering rates, leaching) where plant species occurred. The results of this study indicate that the presence or absence of a plant species, especially desert shrubs, could significantly alter soil chemistry and subsequently ecosystem biogeochemistry and function.
Book
Full-text available
This edition updates a narrative that has been at the forefront of soil science for more than a century. The first edition, published in 1909, was largely a guide to good soil management for farmers in the glaciated regions of New York State in the northeastern U.S. Since then, it has evolved to provide a globally relevant framework for an integrated understanding of the diversity of soils, the soil system and its role in the ecology of planet Earth. The 15th edition is the first to feature full-color illustrations and photographs throughout. These new and refined full color figures and illustrations help make the study of soils more efficient, engaging, and intellectually satisfying. Every chapter has been thoroughly updated with the latest advances, concepts, and applications. Hundreds of new key references have been added. The 15th edition, like preceding editions, has greatly benefited from innumerable suggestions, ideas, and corrections contributed by soil scientists, instructors, and students from around the world. Dr. Nyle Brady, although long in retirement and recently deceased, remains as co-author in recognition of the fact that his vision, wisdom and inspiration continue to permeate the entire book. This edition,1082 pages in length, includes in-depth discussions on such topics of cutting edge soil science as the pedosphere concept, new insights into humus and soil carbon accumulation, subaqueous soils, soil effects on human health, principles and practice of organic farming, urban and human engineered soils, cycling and plant use of silicon, inner- and outer-sphere complexes, radioactive soil contamination, new understandings of the nitrogen cycle, cation saturation and ratios, acid sulfate soils, water-saving irrigation techniques, hydraulic redistribution, cover crop effects on soil health, soil food-web ecology, disease suppressive soils, soil microbial genomics, indicators of soil quality, soil ecosystem services, biochar, soil interactions with global climate change, digital soil maps, and many others. In response to their popularity in recent editions, I have also added many new boxes that present either fascinating examples and applications or technical details and calculations. These boxes both highlight material of special interest and allow the logical thread of the regular text to flow smoothly without digression or interruption. For students: This book provides both an exciting, accessible introduction to the world of soils as well as a reliable, comprehensive reference that you will want to keep for your professional bookshelf. What you learn from its pages will be of enormous practical value in equipping you to meet the many natural-resource challenges of the 21st century. The book demonstrates how the soil system provides many opportunities to see practical applications for principles from such sciences as biology, chemistry, physics, and geology. Throughout, the text highlights the countless interactions between soils and other components of forest, range, agricultural, wetland, and constructed ecosystems. As the global economy expands exponentially societies face new challenges with managing their natural resources. Soil as a fundamental natural resource is critical to sustained economic growth and the prosperity of people in all parts of the world. To achieve balanced growth with a sustainable economy while improving environmental quality, it will be necessary to have a deep understanding of soils, including their properties, functions, ecological roles and management. I have tried to write this textbook in a way designed to engage inquisitive minds and challenge them to understand soils and actively do their part as environmental and agricultural scientists, in the interest of ensuring a prosperous and healthy future for humanity on planet Earth. It is my sincere hope that this book, previous editions of which have served so many generations of soil students and scientists, will continue to help future generations of soil scientists to benefit from a global ecological view of soils.
Article
Full-text available
Landi, M. and Angiolini, C., 2015. Soil-plant relationships in Mediterranean salt marshes across dune-cultivated land gradient The relationships between soil factors and plant species were investigated in salt marshes on the west coast of central Italy along a dune-cultivated land gradient with similar topographic elevations. Plant community composition was quantified in three zones (marsh-dune border, central marsh, and marsh-cultivated land border) identified across the gradient. The results suggest that the distribution and variation in abundance “performance” of plant species is mainly ruled by salinity and soil texture gradients (from sandy to silt-clay). Texture seemed to affect vegetation zonation in the marshes near sand dunes, since at the marsh-dune border the percentage of wind-blown sand increases. Variations in field capacity, total organic carbon, pH, and calcium carbonate did not appear to control the performance of plant species. Indications on the performance of six species are p...
Article
Full-text available
We studied the influence of soil heterogeneity on plant community structure in a semiarid region of Central Mexico using Bray-Curtis Ordination. The results showed that some edaphic factors, such as soil depth, organic matter, and potassium and calcium content, explained 80% of the total variation in structure of the studied communities. We found that soil resources were heterogeneously distributed in the study area, indicating that the edaphic variables considered in this study explain the existing plant community variability, moreover the presence of some shrubs as Krameria cytisoides influences the soil properties, suggesting that there is a reciprocal effect between plant and soil.
Article
Full-text available
Spatial variations of hermatypic coral assemblages were evaluated at five sites in Cayos Cochinos Archipelago, Honduras, in February 2008. Richness and coverage of corals and other benthic morpho-functional groups were estimated using 56 videotransects. Topographic complexity and depth were also measured by transect. Twenty-two coral taxa were recorded for Cayos Cochinos. Total species richness was similar (16 and 17 taxa) at all sites, whereas species richness by transect was different among sites (6-12 taxa). Shannon diversity showed weak differences among sites (1.46-2.13), whereas Pielou evenness was not different among sites. Simpson dominance was low with weak differences among sites (0.15-.27). The total cover of hermatypic coral was 16.5% at Roatan Bank, 10.5% at Salamandinga, 9.7% at Punta Pelicanos, 7.6% at La Grupera, and 6.9% at Mariposales. The ANOSIM revealed assemblages of different corals between sites, except between La Grupera, Punta Pelicanos, and Salamandinga. The NMDS associated La Grupera, Punta Pelicanos, and Salamandinga given the greater contribution of Porites astreoides, Agaricia agaricites, and Montastraea annularis; whereas the NMDS differentiated Mariposales and Roatan Bank, which had more dissimilar assemblages with a greater predominance of Montastraea cavernosa, Agaricia agaricites, and Diploria labyrinthiformis. According to the BIO-ENV method, coral composition and abundance were correlated with the cover of articulated calcareous algae, sandy substrate, total hermatypic corals, rockycalcareous substrate, fleshy macroalgae, and hydrocorals. In general, the differences found in the coral assemblages of Cayos Cochinos could be due to eomorphological characteristics as well as the effects of human activities in the study area.
Chapter
Full-text available
The accumulation of windblown sand creates sand dunes which are one of nature’s most dynamics and intriguing phenomena. Sand dunes are found in most climates of the world as coastal dunes and in some arid regions. Grains of sand between 0.062 and 2.0mm in diameter are not cohesive and therefore are easily carried by the wind. Paradoxically, finer grains of silt and clay (< 0.050mm) are cohesive and can resist wind erosion. This property of sand is reflected in the wind threshold speed curve for sand transport (Fig. 17.1) explaining why dune sand, in most cases, is composed of fine particles between 0.125—0.250 mm.
Article
Full-text available
The diurnal patterns of gas exchange were measured for Prosopis juliflora trees grown under dryland conditions in the Sudan. Our objective was to characterize some of the physiological traits of this species to gain more insight into its ecophysiological characteristics, which may in turn contribute to the improvement of management practices. Maximum photosynthetic rates, obtained early in the morning, peaked at 17.6 μmol m−2 s−1. Maximum transpiration was 102.4 mg m−2 s−1, which corresponded to a maximum stomatal conductance of 0.555 mmol m−2 s−1. A marked decrease in photosynthesis was observed before midday together with a reduction in stomatal conductance and transpiration rate. However, water loss was initially high in early morning, continuing throughout the day at a decreasing rate. The decline in photosynthesis was mainly the result of non-stomatal limitations since the percentage decrease in photosynthesis is larger than that of stomatal conductance. These limitations on photosynthetic activity are likely to have been induced by intensive solar radiation and high temperature and enhanced by the increasing vapour pressure deficit. Stomata were open during the morning to maximize productivity in the favourable period, gradually starting to close towards midday. Stomata did, however, remain slightly open throughout the brief adverse conditions of midday to allow transpiration to protect the photosynthetic apparatus. Results suggest that Prosopis juliflora is aggressively invasive only in areas with an abundant supply of water.
Article
Full-text available
The canopy effects of an exotic and indigenous tree species on soil properties and understorey herbaceous plant species were investigated on the Njemps Flats, Baringo district, Kenya. Samples of soil and herbaceous plant species were obtained within the canopies of systematically selected P. juliflora (exotic) and A. tortilis (indigenous) trees, and from adjacent open areas. Standing biomass, frequency and cover of understorey plant species were significantly (P<0.05) higher in the open area than under the canopies. Cover for herbaceous plant species was 63% under P. juliflora, 82% under A. tortilis and 90% in open areas. All forbs occurred under the canopies indicating that they are more adapted to the shaded microenvironments than grasses. Soils under the tree canopies had significantly (P<0.05) higher organic carbon and total nitrogen than those in adjacent open areas. Soils under A. tortilis had significantly (P<0.05) higher organic carbon and total nitrogen than soils from under P. juliflora. The results suggested that A. tortilis trees are more beneficial to soil physical and chemical properties than P. juliflora. Accordingly, the common practice of clearing woody trees indiscriminately to improve grassland for livestock production or for crop cultivation should not be recommended.
Book
Coastal zones are becoming increasingly topical (and politically sensitive) as they face relentless pressures from urban expansion, recreational development and sea level rise due to climate change. This timely book provides a comprehensive introduction to the formation, dynamics, maintenance and perpetuation of coastal sand dune systems. It describes the interactions between living organisms and the physical processes of geomorphology, with particular emphasis on conservation and management issues due to this habitat's increasingly endangered status. A global range of examples enhance the book's international appeal, which also includes coverage of the latest methods/techniques and experimental approaches with suggestions for student-based field studies and projects. This accessible text is suitable for both senior undergraduate and graduate students taking courses in coastal zone management, marine biology, plant ecology, restoration ecology and conservation biology, as well as the many professional ecologists and conservation biologists requiring a concise but authoritative overview of the topic. The book will also be of relevance and use to coastal managers, planners and naturalists.
Article
The Cayos Cochinos archipelago forms part of the Mesoamerican Barrier Reef System (MBRS) and is one of the first marine protected areas (MPAs) created in Honduras in 1993. However, it has endured historical fishery exploitation prior to protective efforts. The objective of this study was to evaluate the fish assemblages of the archipelago from an ecological and functional diversity perspective in order to test the hypothesis that the low live coral cover, reduced habitat complexity, and overfishing have decreased the biological, ecological, and functional diversity of fish. Our results indicate that the fish assemblages have a high species richness and ecological diversity, compared with other reefs of the MBRS. The sub-massive corals sustain the fish ecological and functional diversity, while leafy corals were associated with low functional diversity. Also, we identified sites with fish assemblages that are in good condition (e.g., Roatan Bank), which can be considered to be a control point for the evaluation of other sites within this MPA. Unfortunately, we also identified sites that were overexploited (e.g., Salamandinga), with low live coral cover and reduced habitat complexity, which also generated a low ecological and functional diversity. This study highlights a functional approach to evaluate fish assemblage conservation in MPAs. This work revealed that habitat complexity loss and overfishing negatively affect functional fish diversity.
Article
Loamy sand soils cannot hold considerable amounts of water and nutrients. A flood-spreading project generates fine particles, often stored in sediment. In addition, established plants have interactive effects on beneath-canopy. This research investigated the effects of flood spreading and Prosopis juliflora on soil characteristics. Fourteen years after the flood-spreading project was initiated, quality of soil was compared between FS and control sites, and the accumulation of nutrients in soil beneath the P. juliflora was compared to soil from between trees with t test. For soils, we analyzed texture, water infiltration, organic carbon, pH, total nitrogen, available phosphorus, available potassium, cation exchange capacity, calcium carbonate equilibrium, and soil microbial respiration, and for plants, we measured the below-ground root. Few variations were found in the soil characteristics as a result of flood-spreading establishment. The results indicated that fine fractions of soil in FS site were greater than that in control (p < 0.05). It was obvious that flood spreading and P. juliflora could alter soil infiltration rate. The soil infiltration rate of the under P. juliflora had the highest value (3.05 ± 0.22 cm h⁻¹), and in flood-spreading site without P. juliflora had the lowest value (2.48 ± 0.20 cm h⁻¹). FS had a significant improvement in soil nutrient concentration and soil microbial respiration. This research suggests that flood spreading in coarse texture soils provided a beneficial approach to remediation of sandy soil characteristics. In addition, P. juliflora had a significant effect on developing soil fertility under plant canopy.
Article
Soil aggregation is considered as a crucial process in agro-system sustainability due to the role in soil physical, chemical and biological dynamics. Here we tested the hypothesis that the initial chemical traits of organic matter (OM) may help to explain the variability of soil aggregation dynamics after organic amendment. We characterized ten OM types (alfalfa litter, biochar, cellulose, glucose, green compost, maize litter, manure compost, meat powder, sawdust, and solid digestate) by ¹³C-CPMAS NMR and elemental chemical features to investigate the effects of amendment quality on soil aggregation. In a manipulative factorial experiment, dry samples (200 g) of three soil types (S1, S2 and S3) with different texture, high pH (7–9), and similar OM content, were incorporated with 4 g (2% w/w) of dry, 2 mm-grounded OM, incubated in mesocosms for 300 days under controlled temperature (18 ± 2 °C night and 24 ± 2 °C day), and sampled at 4 dates for measuring aggregation index (AI), based on water stability of soil aggregates (WSA). We found that meat powder and alfalfa litter induced a rapid initial increase of AI, exceeding that of the controls by one to two orders of magnitude, likely acting as a C source for microbes. Biochar incorporation in soil barely affected AI, with intermediate effects with other OM types. Considering C bond types corresponding to OM ¹³C-CPMAS NMR spectral regions, carbonyl C was only correlated to early AI, possibly due to overlapping signals of amide structures; O-alkyl C and di-O-alkyl C (carbohydrate fraction) were positively associated to AI, indicating a promoting effect on soil structure, while aromatic C fractions showed an opposite pattern, possibly related to aggregate protection by coatings associated to water repellency, or to direct aggregate internal binding. This study demonstrates that OM chemical quality plays an important role in soil aggregation process, with the molecular composition defined by ¹³C-CPMAS NMR spectroscopy being more predictive of aggregation dynamics compared to classical elemental features. As such, this study provides a significant novel contribution to clarify the relationships between OM chemistry and soil aggregation.
Book
The text begins with an introduction to concepts and terminology, and the factors that have affected coastal evolution and coastline changes (Chapter 1). This is followed by a discussion of waves, tides, currents and other nearshore processes (Chapter 2), and a study of the effects of land and sea level changes, notably the Holocene marine transgression, which has played a major part in shaping modern coastlines and can be regarded as a unifying theme in coastal geomorphology (Chapter 3). Cliffs are discussed in Chapter 4 and the shore platforms that border them in Chapter 5. Chapter 6 deals with the origin of beaches and the changes taking place on them, and Chapter 7 with the beach erosion problem. Spits, barriers and bars are discussed in Chapter 8 and the formation of coastal dunes in Chapter 9. Intertidal wetlands, including mudflats, salt marshes and mangroves are dealt with in Chapter 10, followed by estuaries and lagoons, including other inlets (rias, fiords, fiards, calanques, sharms and sebkhas) in Chapter 11. Chapter 12 considers deltas produced by deposition at river mouths, and Chapter 13 reviews coral and algal reefs. Chapter 14 deals with future coasts. There are 187 illustrations and 15 tables. Details of articles cited are given in the References section, which includes many pre-2000 publications that remain relevant.
Article
Cropland abandonment and subsequent revegetation processes (due to secondary succession and afforestation practices) are global issues with important implications in Mediterranean mountain areas. Several publications have reviewed the impact of cropland abandonment and revegetation on the soil properties dynamics but, so far, limited attention has been paid to Mediterranean humid mountain areas. This paper examines six neighbouring land covers, in the Central Spanish Pyrenees to determine the effects of land covers, cropland abandonment and consequently secondary succession and afforestation practices on soil properties. For this purpose, a total of 85 samples from 6 land covers and from two soil depths were analysed. We observed that changes in soil properties after cropland abandonment were limited, even if afforestation practices were carried out, and no differences were observed between natural succession and afforestation. Land cover and depth had a significant effect on the physical and chemical variables, being larger in the uppermost 0–10 cm depth. The organic and inorganic carbon and N concentration, SOC and TN stocks, CN ratio, organic matter, and bulk density showed significant differences. Afforestation improved soil properties, aggregate stability and carbon concentration and stocks when compared to neighbouring bare soils. A soil quality index �based on statistical analysis- suggested that natural forests and Pinus nigra areas developed a higher soil quality rating. Our general results also demonstrated that the impact of disturbance by afforestation techniques (microsites) is difficult to discern. The differences found with respect to the native forest appear to indicate that the afforested soils have not yet reached their maximum soil quality and maximum potential as soil organic carbon sink. As there was no difference found between the soil improvement by natural succession in comparison to afforestation, these results put the question forward which type of forest and landscape management is most appropriate to decide for the best practices after cropland abandonment for soil recovery and erosion control.
Article
Afforestation is an important means of controlling desertification and of restoring vegetation on land that has become desert. The procedure leads to changes in the dynamics of organic carbon (C) in the soil as xerophytic shrubs are established, but the dynamics are still poorly understood, partly because of the lack of long-term observations. Progressive measures to bind sand dunes along the route of the Baotou–Lanzhou railway on the south eastern edge of the Tengger Desert in China, which were begun in 1956, provide the opportunity to study such changes. We sampled the topsoil (0–10 cm) from 10 sites that represent a chronosequence and vary in age from 1 to 57 years since sand-binding measures and afforestation were begun. These measures evidently trapped increasing amounts of clay and silt, and with them increased the concentrations of both available phosphorus (P) and available potassium (K). By analysing the organic C in the samples we have been able to describe quantitatively the changes in several C fractions over time. We found that total C, its light and heavy fractions, dissolved C and microbial C all increase slowly at first after afforestation, then more rapidly, and then at a decreasing rate. They seem to be examples of logistic growth and could be described by logistic equations. The light fraction increased faster than the total C, as did the microbial C during the first 19 years. The light C fraction was the most sensitive for identifying changes in soil C after afforestation. Over the full 57 years, the contributions of the light and microbial fractions to total C increased, while those of the heavy fraction and dissolved C decreased. Our results suggest that the proportion of C in labile pools increased, but the proportion in stable pools decreased, which would increase the risk of substantial losses of C caused by potential global warming and human-induced disturbances.
Article
Evidence is mounting that the immense diversity of microorganisms and animals that live belowground contributes significantly to shaping aboveground biodiversity and the functioning of terrestrial ecosystems. Our understanding of how this belowground biodiversity is distributed, and how it regulates the structure and functioning of terrestrial ecosystems, is rapidly growing. Evidence also points to soil biodiversity as having a key role in determining the ecological and evolutionary responses of terrestrial ecosystems to current and future environmental change. Here we review recent progress and propose avenues for further research in this field.
Article
To test direct and indirect effects of glomalin, mycorrhizal hyphae, and roots on aggregate stability, perspex pots separated by 37-μm nylon mesh in the middle were used to form root-free hyphae and root/hyphae chambers, where trifoliate orange (Poncirus trifoliata) seedlings were colonized by Funneliformis mosseae or Paraglomus occultum in the root/hyphae chamber. Both fungal species induced significantly higher plant growth, root total length, easily-extractable glomalin-related soil protein (EE-GRSP) and total GRSP (T-GRSP), and mean weight diameter (an aggregate stability indicator). The Pearson correlation showed that root colonization or soil hyphal length significantly positively correlated with EE-GRSP, difficultly-extractable GRSP (DE-GRSP), T-GRSP, and water-stable aggregates in 2.00-4.00, 0.50-1.00, and 0.25-0.50 mm size fractions. The path analysis indicated that in the root/hyphae chamber, aggregate stability derived from a direct effect of root colonization, EE-GRSP or DE-GRSP. Meanwhile, the direct effect was stronger by EE-GRSP or DE-GRSP than by mycorrhizal colonization. In the root-free hyphae chamber, mycorrhizal-mediated aggregate stability was due to total effect but not direct effect of soil hyphal length, EE-GRSP and T-GRSP. Our results suggest that GRSP among these tested factors may be the primary contributor to aggregate stability in the citrus rhizosphere.
Article
The water relations of arbuscular mycorrhizal plants have been compared often, but virtually nothing is known about the comparative water relations of mycorrhizal and nonmycorrhizal soils. Mycorrhizal symbiosis typically affects soil structure, and soil structure affects water retention properties; therefore, it seems likely that mycorrhizal symbiosis may affect soil water relations. We examined the water retention properties of a Sequatchie fine sandy loam subjected to three treatments: seven months of root growth by (1) nonmycorrhizal Vigna unguiculata given low phosphorus fertilization, (2) nonmycorrhizal Vigna unguiculata given high phosphorus fertilization, (3) Vigna unguiculata colonized by Glomus intraradices and given low phosphorus fertilization. Mycorrhization of soil had a slight but significant effect on the soil moisture characteristic curve. Once soil matric potential (Ψ_m) began to decline, changes in Ψ_m per unit change in soil water content were smaller in mycorrhizal than in the two nonmycorrhizal soils. Within the range of about -1 to -5 MPa, the mycorrhizal soil had to dry more than the nonmycorrhizal soils to reach the same Ψ_ m. Soil characteristic curves of nonmycorrhizal soils were similar, whether they contained roots of plants fed high or low phosphorus. The mycorrhizal soil had significantly more water stable aggregates and substantially higher extraradical hyphal densities than the nonmycorrhizal soils. Importantly, we were able to factor out the possibly confounding influence of differential root growth among mycorrhizal and nonmycorrhizal soils. Mycorrhizal symbiosis affected the soil moisture characteristic and soil structure, even though root mass, root length, root surface area and root volume densities were similar in mycorrhizal and nonmycorrhizal soils.
Article
A DTPA soil test was developed to identify near‐neutral and calcareous soils with insufficient available Zn, Fe, Mn, or Cu for maximum yields of crops. The extractant consists of 0.005 M DTPA (diethylenetriaminepentaacetic acid), 0.1 M triethanolamine, and 0.01 M CaCl 2 , with a pH of 7.3. The soil test consists of shaking 10 g of air‐dry soil with 20 ml of extractant for 2 hours. The leachate is filtered, and Zn, Fe, Mn, and Cu are measured in the filtrate by atomic absorption spectrophotometry. The soil test successfully separated 77 Colorado soils on the basis of crop response to Zn, Fe, and Mn fertilizers. Critical nutrient levels must be determined separately for each crop using standardized procedures for soil preparation, grinding, and extraction. The critical levels for corn using the procedures reported herein were: 0.8 ppm for Zn, 4.5 ppm for Fe, and tentatively 1.0 ppm for Mn, and 0.2 ppm for Cu. Development of the soil test was based, in part, on theoretical considerations. The extractant is buffered at pH 7.30 and contains CaCl 2 so that equilibrium with CaCO 3 is established at a CO 2 level about 10 times that of the atmosphere. Thus, the extractant precludes dissolution of CaCO 3 and the release of occluded nutrients which are normally not available to plants. DTPA was selected as the chelating agent because it can effectively extract all four micronutrient metals. Factors such as pH, concentration of chelating agent, time of shaking, and temperature of extraction affect the amount of micronutrients extracted and were adjusted for maximum overall effectiveness.
Article
A new, two‐step procedure is presented for determining the cation exchange capacity (CEC) of calcareous and gypsiferous soils. The method eliminates most of the errors inherent in conventional methods. The cation exchange sites are saturated with sodium by four successive “equilibrations” of the soil (4–5 g) with 33‐ml increments of a pH 8.2, 60% ethanol solution of 0.4N NaO Ac − 0.1 N NaCl (saturating solution). The saturated sample then is extracted with three 33‐ml increments of 1.0 N , pH 7 magnesium nitrate. Total sodium (Na t ) and chloride (Cl t ) are subsequently determined in the extracted solution. Chloride (Cl t ) is determined so that the soluble sodium (Na sol ), from the excess saturating solution carried over from the saturation step to the extraction step, may be deducted from the total sodium (Na t ) to obtain exchangeable sodium (Na exch ), which is equivalent to the CEC. Thus, CEC = Na exch = (Na t − Na sol ) = Na t − [Cl t (Na/Cl) saturating solution ] where (Na/Cl) saturating solution is the ratio of Na to Cl in the saturating solution.
Article
It has been speculated that arbuscular mycorrhizal fungi (AMF) produce extracellular compounds and that these are involved in soil stabilization. An unusual and abundant protein was found on hyphae of AMF, and it was hypothesized that the hyphal protein could be found in soil. The purpose of this work was to test extraction conditions for soil protein on a range of soils collected from undisturbed sites, to compare protein from hyphae with protein from soils, and to examine the relationship between soil protein and percent of total dry weight of soil made up of ca. 1 to 2-mm water stable aggregates. The A-horizons of 12 acidic soils collected from the midAtlantic area of the United States were used to develop a protocol for protein extraction. Protein was measured by the Bradford assay, with bovine serum albumin as the standard. Also, an indirect enzyme-linked immunosorbent assay (ELISA), using the monoclonal antibody that had been used to detect the protein on hyphae of AMF, was performed on 0.5 μg of protein from soil or hyphae. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of denatured protein was used to compare soil protein with hyphal protein. The extraction conditions that gave the best results for total protein were 0.25 g soil in 2 mL of 50 mM citrate, pH 8.0, for 90 min at 121°C yielding a range of 4.4 to 14.4 mg protein/g of soil for these soils. Highest ELISA values were obtained by using 20 mM citrate, pH 7.0, for 30 min at 121°C, but less protein was extracted under these conditions. Crude extracts of protein from hyphae and soil showed the same banding patterns and density of bands on SDS-PAGE gels. ELISA values for soils were between 60 and 107% of hyphal ELISA values. Total protein concentration was correlated linearly with organic carbon in soil (r2 = 0.85, P ≤ 0.001). The percent dry weight of soil composed of water-stable aggregates was correlated positively (P ≤ 0.05) with silt and ELISA values and correlated negatively with sand. The possible contribution of this protein to soil stabilization is discussed.
Article
Glomalin is described in the literature as a N-linked glycoprotein and the putative gene product of arbuscular mycorrhizal fungi (AMF). Since the link between glomalin and various protein fractions in soil is not yet clearly defined, glomalin-related soil protein (GRSP) more appropriately describes glomalin's existence in natural organic matter (NOM). The objective of this study was to examine the chemical characteristics of GRSP present in several mineral and organic soils of varying organic carbon content. GRSP was isolated using high temperature sodium citrate extraction followed by either trichloroacetic acid (TCA) or hydrochloric acid (HCl) precipitation. GRSP was characterized by quantitative solid-state 13C DPMAS NMR, infrared (IR) spectroscopy, elemental analysis, and the Bradford assay for protein content. GRSP accounted for 25% and 52% of total C in the mineral soils and organic soil, respectively. Molar C/N and H/C ratios reveal that GRSP has less nitrogen than bovine serum albumin (BSA), and that GRSP extracted from the Pahokee peat soil possessed a more unsaturated, and thus aromatic character relative to the mineral soil GRSP, respectively. GRSP's high aromatic (42–49%) and carboxyl (24–30%) carbon contents and low aliphatic (4–11%) and carbohydrate-type carbon contents (4–16%) suggests that GRSP does not resemble a typical glycoprotein. In fact, the NMR spectra of GRSP closely resemble that of humic acid. GRSP extracted from mineral and organic soils possessed the same NMR fingerprint regardless of the precipitation method used (i.e., either TCA or HCl). It is likely that the current GRSP extraction methods, because of their similarity to the method used to extract humic acid, are coextracting both materials.
Article
A survey of 659 papers mostly published since 1987 was conducted to compile a checklist of mycorrhizal occurrence among 3,617 species (263 families) of land plants. A plant phylogeny was then used to map the mycorrhizal information to examine evolutionary patterns. Several findings from this survey enhance our understanding of the roles of mycorrhizas in the origin and subsequent diversification of land plants. First, 80 and 92% of surveyed land plant species and families are mycorrhizal. Second, arbuscular mycorrhiza (AM) is the predominant and ancestral type of mycorrhiza in land plants. Its occurrence in a vast majority of land plants and early-diverging lineages of liverworts suggests that the origin of AM probably coincided with the origin of land plants. Third, ectomycorrhiza (ECM) and its derived types independently evolved from AM many times through parallel evolution. Coevolution between plant and fungal partners in ECM and its derived types has probably contributed to diversification of both plant hosts and fungal symbionts. Fourth, mycoheterotrophy and loss of the mycorrhizal condition also evolved many times independently in land plants through parallel evolution.
Prosopis juliflora. In www.cabi.org/isc
  • N Pasiecznik
Simbiosis micorrícica: Un análisis de su relevante función ecosistémica y en la provisión de servicios ambientales
  • C Neri-Luna
  • L Villarreal-Ruiz
Invasion of Rosa rugosa induced changes in soil nutrients and microbial communities of coastal sand dunes.
  • A.M. Stefanowicz
  • S. Zubek
  • M. Stanek
  • I.M. Grze
  • E. Roej-Pabijan
  • J. Baszkowski
  • M.W. Woch
Effect of fisheries and benthic habitat on the ecological and functional diversity of fish at the Cayos Cochinos coral reefs (Honduras).
  • I. Cceres
  • E.C. Ibarra-Garca
  • M. Ortiz
  • M. Ayn-Parente
  • F.A. Rodrguez-Zaragoza
Nodulation and nitrogen fixation in Prosopis juliflora (Sw) DC. In
  • A.A. Franco
  • S.M. de Faria
  • V.C.G. Moreira
  • E.M.S. Monteiro
  • M.A. Habit
  • J.D. Saavedra
NitrogenInorganic forms. In
  • D.R. Keeney
  • D.W. Nelson
  • A.L. Page
Modificaciones al sistema de clasificación climática de Köppen
  • E García