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1
LIM, BURTON K., and MARK D. ENGSTROM. "Bat community structure at Iwokrama Forest, Guyana." Journal of Tropical Ecology 17, no. 5 (2001): 647–65. http://dx.doi.org/10.1017/s0266467401001481.
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With 86 species, Iwokrama Forest in central Guyana has the highest reported bat biodiversity for a protected area in the world. Using standardized capture data for 73 of these 86 species, we document community structure of bats in terms of species diversity, relative abundance, gross biomass, feeding guilds, vertical stratification and a trophic-size niche matrix. Based on faunal surveys in 1997, with similar amounts of effort in the forest canopy and at ground level, the greater fruit-eating bat (Artibeus lituratus) was by far the most ecologically dominant species in terms of frequency of capture and biomass. In total, frugivores comprised 70% of the species diversity and 78% of the biomass. The most common species of bat were fully partitioned in a resource niche matrix of size and trophic guild when vertical stratification was included as a variable. We conclude that resource partitioning and species packing differentially affect relative size in tropical bats, and are better summarized and analysed in three dimensions.
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Lim, Burton K., and Mark D. Engstrom. "Bat community structure at Iwokrama Forest, Guyana." Journal of Tropical Ecology 17, no. 5 (2001): 647–65. https://doi.org/10.5281/zenodo.14818064.
Full textAbstract:
(Uploaded by Plazi for the Bat Literature Project) With 86 species, Iwokrama Forest in central Guyana has the highest reported bat biodiversity for a protected area in the world. Using standardized capture data for 73 of these 86 species, we document community structure of bats in terms of species diversity, relative abundance, gross biomass, feeding guilds, vertical stratification and a trophic–size niche matrix. Based on faunal surveys in 1997, with similar amounts of effort in the forest canopy and at ground level, the greater fruit-eating bat (Artibeus lituratus) was by far the most ecologically dominant species in terms of frequency of capture and biomass. In total, frugivores comprised 70% of the species diversity and 78% of the biomass. The most common species of bat were fully partitioned in a resource niche matrix of size and trophic guild when vertical stratification was included as a variable. We conclude that resource partitioning and species packing differentially affect relative size in tropical bats, and are better summarized and analysed in three dimensions.
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Oelbaum, Phillip J., M. Brock Fenton, Nancy B. Simmons, and Hugh G. Broders. "Community structure of a Neotropical bat fauna as revealed by stable isotope analysis: Not all species fit neatly into predicted guilds." Biotropica 51, no. 5 (2019): 719–30. https://doi.org/10.5281/zenodo.13521743.
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(Uploaded by Plazi for the Bat Literature Project) Neotropical bat communities are among the most diverse mammal communities in the world, and a better understanding of these assemblages may permit inferences about how so many species coexist. While broad trophic guilds (e.g., frugivore, insectivore) of bats are recognized, details of diet and similarities among species remain largely unknown. We used stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) to characterize the community structure of a diverse Neotropical bat fauna from Belize to test predictions of niche theory and the competitive exclusion principle. We predicted that (1) interspecific variation in isotopic overlap would be greater within guilds than between guilds, and (2) no two sympatric populations would have isotopic niches that overlap completely, unless there is variation along some other axis (e.g., temporal, spatial). We additionally tested body size as an explanatory metric of potential overlap and predicted that larger‐bodied animals would have greater niche breadths. Results suggest that while guild‐level characterizations of communities are at least somewhat informative, there are multiple examples of intra‐ and inter‐guild species pairs with significantly overlapping isotopic niches, suggesting that, counter to predictions, they may compete for resources. Understanding the trophic structure of animal communities is fundamental to conservation and management of endangered species and ecosystems and important for evolutionary studies, and stable isotope analyses can provide key insights as well as informing hypotheses of the diet of species that are not well known.
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Oelbaum, Phillip J., M. Brock Fenton, Nancy B. Simmons, and Hugh G. Broders. "Community structure of a Neotropical bat fauna as revealed by stable isotope analysis: Not all species fit neatly into predicted guilds." Biotropica 51, no. 5 (2019): 719–30. https://doi.org/10.5281/zenodo.13521754.
Full textAbstract:
(Uploaded by Plazi for the Bat Literature Project) Neotropical bat communities are among the most diverse mammal communities in the world, and a better understanding of these assemblages may permit inferences about how so many species coexist. While broad trophic guilds (e.g., frugivore, insectivore) of bats are recognized, details of diet and similarities among species remain largely unknown. We used stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) to characterize the community structure of a diverse Neotropical bat fauna from Belize to test predictions of niche theory and the competitive exclusion principle. We predicted that (1) interspecific variation in isotopic overlap would be greater within guilds than between guilds, and (2) no two sympatric populations would have isotopic niches that overlap completely, unless there is variation along some other axis (e.g., temporal, spatial). We additionally tested body size as an explanatory metric of potential overlap and predicted that larger‐bodied animals would have greater niche breadths. Results suggest that while guild‐level characterizations of communities are at least somewhat informative, there are multiple examples of intra‐ and inter‐guild species pairs with significantly overlapping isotopic niches, suggesting that, counter to predictions, they may compete for resources. Understanding the trophic structure of animal communities is fundamental to conservation and management of endangered species and ecosystems and important for evolutionary studies, and stable isotope analyses can provide key insights as well as informing hypotheses of the diet of species that are not well known.
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Oelbaum, Phillip J., M. Brock Fenton, Nancy B. Simmons, and Hugh G. Broders. "Community structure of a Neotropical bat fauna as revealed by stable isotope analysis: Not all species fit neatly into predicted guilds." Biotropica 51, no. 5 (2019): 719–30. https://doi.org/10.5281/zenodo.13521743.
Full textAbstract:
(Uploaded by Plazi for the Bat Literature Project) Neotropical bat communities are among the most diverse mammal communities in the world, and a better understanding of these assemblages may permit inferences about how so many species coexist. While broad trophic guilds (e.g., frugivore, insectivore) of bats are recognized, details of diet and similarities among species remain largely unknown. We used stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) to characterize the community structure of a diverse Neotropical bat fauna from Belize to test predictions of niche theory and the competitive exclusion principle. We predicted that (1) interspecific variation in isotopic overlap would be greater within guilds than between guilds, and (2) no two sympatric populations would have isotopic niches that overlap completely, unless there is variation along some other axis (e.g., temporal, spatial). We additionally tested body size as an explanatory metric of potential overlap and predicted that larger‐bodied animals would have greater niche breadths. Results suggest that while guild‐level characterizations of communities are at least somewhat informative, there are multiple examples of intra‐ and inter‐guild species pairs with significantly overlapping isotopic niches, suggesting that, counter to predictions, they may compete for resources. Understanding the trophic structure of animal communities is fundamental to conservation and management of endangered species and ecosystems and important for evolutionary studies, and stable isotope analyses can provide key insights as well as informing hypotheses of the diet of species that are not well known.
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Oelbaum, Phillip J., M. Brock Fenton, Nancy B. Simmons, and Hugh G. Broders. "Community structure of a Neotropical bat fauna as revealed by stable isotope analysis: Not all species fit neatly into predicted guilds." Biotropica 51, no. 5 (2019): 719–30. https://doi.org/10.5281/zenodo.13521754.
Full textAbstract:
(Uploaded by Plazi for the Bat Literature Project) Neotropical bat communities are among the most diverse mammal communities in the world, and a better understanding of these assemblages may permit inferences about how so many species coexist. While broad trophic guilds (e.g., frugivore, insectivore) of bats are recognized, details of diet and similarities among species remain largely unknown. We used stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) to characterize the community structure of a diverse Neotropical bat fauna from Belize to test predictions of niche theory and the competitive exclusion principle. We predicted that (1) interspecific variation in isotopic overlap would be greater within guilds than between guilds, and (2) no two sympatric populations would have isotopic niches that overlap completely, unless there is variation along some other axis (e.g., temporal, spatial). We additionally tested body size as an explanatory metric of potential overlap and predicted that larger‐bodied animals would have greater niche breadths. Results suggest that while guild‐level characterizations of communities are at least somewhat informative, there are multiple examples of intra‐ and inter‐guild species pairs with significantly overlapping isotopic niches, suggesting that, counter to predictions, they may compete for resources. Understanding the trophic structure of animal communities is fundamental to conservation and management of endangered species and ecosystems and important for evolutionary studies, and stable isotope analyses can provide key insights as well as informing hypotheses of the diet of species that are not well known.
7
Burress, Edward D., Alejandro Duarte, Michael M. Gangloff, and Lynn Siefferman. "Isotopic trophic guild structure of a diverse subtropical South American fish community." Ecology of Freshwater Fish 22, no. 1 (2012): 66–72. http://dx.doi.org/10.1111/eff.12002.
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Bento, Marta, José Paula, Salomão Bandeira, and Alexandra Marçal Correia. "Catching the Drift of Marine Invertebrate Diversity through Digital Repositories—A Case Study of the Mangroves and Seagrasses of Maputo Bay, Mozambique." Diversity 15, no. 2 (2023): 242. http://dx.doi.org/10.3390/d15020242.
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Mangroves and seagrasses present with high marine macroinvertebrate biodiversity that contributes to their structure and functioning. Macroinvertebrates possess a broad range of functional traits, making them excellent models for biodiversity and available-trait-based studies. This study aimed to characterize the biodiversity of marine macroinvertebrates as two different ecosystems situated along the coastline of Maputo Bay by compiling dispersed data from online databases. Specifically, this study addressed species richness, taxonomic and functional diversity based on two traits (habitat occupation and trophic guild), and the community structure of these traits. Mangroves presented with a higher species richness and taxonomic diversity than seagrasses. The functional diversity of mangroves was mostly explained by the trophic guild trait. In the case of seagrasses, functional diversity was mostly due to differences in habitat occupation in the 20th century, but the trophic guild accounted for this functional diversity from 2000 onwards. The comparison of community compositions between the two ecosystems showed low or no similarity. The use of digital databases revealed some limitations, mostly regarding the sampling methods and individual counts. The trends and data gaps presented in this study can be further used to inform subsequent systematic data acquisition and support the development of future research. A further step that may be taken to improve the use of digital data in future biodiversity studies is to fully incorporate functional traits, abundance and sampling methods into online databases.
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Whitehouse, George A., Troy W. Buckley, and Seth L. Danielson. "Diet compositions and trophic guild structure of the eastern Chukchi Sea demersal fish community." Deep Sea Research Part II: Topical Studies in Oceanography 135 (January 2017): 95–110. http://dx.doi.org/10.1016/j.dsr2.2016.03.010.
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Voss, Robert S., David W. Fleck, Richard E. Strauss, Paúl M. Velazco, and Nancy B. Simmons. "Roosting Ecology of Amazonian Bats: Evidence for Guild Structure in Hyperdiverse Mammalian Communities." American Museum Novitates 3870, no. 3870 (2016): 1–43. https://doi.org/10.5281/zenodo.13522928.
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(Uploaded by Plazi for the Bat Literature Project) The ecological mechanisms that sustain high species richness in Neotropical bat communities have attracted research attention for several decades. Although many ecologists have studied the feeding behavior and diets of Neotropical bats on the assumption that food is a limiting resource, other resource axes that might be important for species coexistence are often ignored. Diurnal refugia, in particular, are a crucial resource for bats, many of which exhibit conspicuous morphological or behavioral adaptations to the roost environment. Here we report and analyze information about roost occupancy based on >500 field observations of Amazonian bats. Statistical analyses of these data suggest the existence of distinct groups of species roosting (1) in foliage, (2) exposed on the trunks of standing trees, (3) in cavities in standing trees, (4) in or under fallen trees, (5) beneath undercut earth banks, and (6) in arboreal insect nests; additionally, we recognize other groups that roost (7) in animal burrows, and (8) in rocks or caves. Roosting-guild membership is hypothesized to have a filtering effect on Amazonian bat community composition because some types of roosts are absent or uncommon in certain habitats. Among other applications of our results, cross-classifying bat species by trophic and roosting guilds suggests that the often-reported deficit of gleaning animalivores in secondary vegetation by comparison with primary forest might reflect habitat differences in roost availability rather than food resources. In general, ecological and evolutionary studies of Neotropical bats would be enhanced by considering both trophic- and roosting-guild membership in future analyses, but additional fieldwork will be required to determine the roosting behavior of many data-deficient species.
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Voss, Robert S., David W. Fleck, Richard E. Strauss, Paúl M. Velazco, and Nancy B. Simmons. "Roosting Ecology of Amazonian Bats: Evidence for Guild Structure in Hyperdiverse Mammalian Communities." American Museum Novitates 3870, no. 3870 (2016): 1–43. https://doi.org/10.5281/zenodo.13522928.
Full textAbstract:
(Uploaded by Plazi for the Bat Literature Project) The ecological mechanisms that sustain high species richness in Neotropical bat communities have attracted research attention for several decades. Although many ecologists have studied the feeding behavior and diets of Neotropical bats on the assumption that food is a limiting resource, other resource axes that might be important for species coexistence are often ignored. Diurnal refugia, in particular, are a crucial resource for bats, many of which exhibit conspicuous morphological or behavioral adaptations to the roost environment. Here we report and analyze information about roost occupancy based on >500 field observations of Amazonian bats. Statistical analyses of these data suggest the existence of distinct groups of species roosting (1) in foliage, (2) exposed on the trunks of standing trees, (3) in cavities in standing trees, (4) in or under fallen trees, (5) beneath undercut earth banks, and (6) in arboreal insect nests; additionally, we recognize other groups that roost (7) in animal burrows, and (8) in rocks or caves. Roosting-guild membership is hypothesized to have a filtering effect on Amazonian bat community composition because some types of roosts are absent or uncommon in certain habitats. Among other applications of our results, cross-classifying bat species by trophic and roosting guilds suggests that the often-reported deficit of gleaning animalivores in secondary vegetation by comparison with primary forest might reflect habitat differences in roost availability rather than food resources. In general, ecological and evolutionary studies of Neotropical bats would be enhanced by considering both trophic- and roosting-guild membership in future analyses, but additional fieldwork will be required to determine the roosting behavior of many data-deficient species.
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Rayner, Thomas S., Bradley J. Pusey, and Richard G. Pearson. "Spatio-temporal dynamics of fish feeding in the lower Mulgrave River, north-eastern Queensland: the influence of seasonal flooding, instream productivity and invertebrate abundance." Marine and Freshwater Research 60, no. 2 (2009): 97. http://dx.doi.org/10.1071/mf08055.
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Wet-season flooding causes dietary shifts in tropical freshwater fish by regulating instream productivity, habitat structure and food availability. These dynamics have been comprehensively documented worldwide, but data are limited for Australia’s Wet Tropics rivers. The aim of the present study was to extend our earlier fish–habitat model for these systems by examining the role of trophic dynamics in determining fish assemblage composition. Chlorophyll a and phaeophytin concentrations, benthic and littoral invertebrates and fish were collected at four sites in the lower Mulgrave River under a range of flow conditions. Wet-season flooding caused significant reductions in instream productivity, whereas habitat disturbance reduced densities and abundances of littoral and benthic invertebrates. However, volumetric gut contents of 1360 fish, from 36 species, revealed seasonal shifts in guild membership by only two species, with fish moving between sites to target their preferred prey items – largely irrespective of differences in habitat structure. As a result, the food consumed by the fish community present at each site closely reflected the seasonal availability of food resources. The present paper questions whether fish community composition in small tropical rivers can be accurately predicted from habitat surrogates alone and encourages consideration of constraints imposed by the trophic dynamics and reproductive ecology of fish.
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McCoy, Sophie J., Stefano Allesina, and Catherine A. Pfister. "Ocean acidification affects competition for space: projections of community structure using cellular automata." Proceedings of the Royal Society B: Biological Sciences 283, no. 1826 (2016): 20152561. http://dx.doi.org/10.1098/rspb.2015.2561.
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Historical ecological datasets from a coastal marine community of crustose coralline algae (CCA) enabled the documentation of ecological changes in this community over 30 years in the Northeast Pacific. Data on competitive interactions obtained from field surveys showed concordance between the 1980s and 2013, yet also revealed a reduction in how strongly species interact. Here, we extend these empirical findings with a cellular automaton model to forecast ecological dynamics. Our model suggests the emergence of a new dominant competitor in a global change scenario, with a reduced role of herbivory pressure, or trophic control, in regulating competition among CCA. Ocean acidification, due to its energetic demands, may now instead play this role in mediating competitive interactions and thereby promote species diversity within this guild.
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Stevens, Cameron E., Trevor Council, and Michael G. Sullivan. "Influences of Human Stressors on Fish-Based Metrics for Assessing River Condition in Central Alberta." Water Quality Research Journal 45, no. 1 (2010): 35–46. http://dx.doi.org/10.2166/wqrj.2010.005.
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Abstract Economic developments in Alberta have resulted in widespread changes in land use that may deteriorate river conditions for fish. Fish assemblages were characterized with index of biological integrity metrics for the heavily-developed watershed of the Battle River, Alberta. Metric relationships with human stressors were quantified using regression and information theory methods. Although the fauna comprised 14 native species, 50% of the catch was white sucker (Catostomus commersoni Lacepede, 1803). Five statistically unrelated metrics were identified as being responsive to stressors: two trophic guilds, one habitat guild, one reproductive guild, and one measure of community structure. Regression showed that the cumulative effect of human developments, indexed as road density in the basin, was negatively linked to the relative abundance of lithophils and positively linked to the relative abundance of omnivores. Agriculture also threatened the integrity of fish assemblages. Stream sections with higher cattle densities in their basins had fewer lithophils and benthic invertivores; whereas stream sections with higher nutrient concentrations contained fewer species, as well as fewer top carnivores, but more true omnivores. Understanding effects of human footprints that are expanding in western Canada will be critical to the successful management of aquatic resources.
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Vanderwel, Mark C., Jay R. Malcolm, Sandy M. Smith, and Nurul Islam. "Insect community composition and trophic guild structure in decaying logs from eastern Canadian pine-dominated forests." Forest Ecology and Management 225, no. 1-3 (2006): 190–99. http://dx.doi.org/10.1016/j.foreco.2005.12.051.
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Sánchez Montenegro, Juan Pablo, Katherine Pérez Castillo, Mario Fernando Garcés Restrepo, and Alan Giraldo. "Bird assemble associated to two landscape units in a tropical dry forest." Boletín Científico Centro de Museos Museo de Historia Natural 21, no. 2 (2017): 115–30. http://dx.doi.org/10.17151/bccm.2017.21.2.8.
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The transformation of ecosystems through human activities can affect the biological and ecological processes of bird species, and can even lead to groups of species becoming isolated due to deforestation, causing a decrease in genetic diversity and the extirpation of species. To evaluate the composition and structure of bird communities associated with the tropical dry forest ecosystem in the Guarinocito jurisdiction (La Victoria, Caldas) we identified two landscape units: a forest area (dry forest matrix) and an interfered area (matrix of lands), presenting human intervention such as roads and grassland systems. Point counts of 10 min long were carried out in each unit to survey birds between 06:00 and 09:00 hours and between 16:00 and 18:00 hours. Mist nets were set up to complete the species record. Three four-day long sampling trips were carried out in April 2013, November 2013, and October 2014 to consider the seasonal variability that affects the environmental conditions in the study area. The sampling representativeness was evaluated using non-parametric estimates. All observed or captured individuals were assigned to a trophic guild in order to evaluate the community structure in the two established landscape units. A total of 1,005 individuals from 36 families and 127 species were recorded. The most abundant species were Thraupis episcopus (7.36%) and Sicalis flaveola (6.77%). Sample representativeness ranged from 68.18% (Jack 2) to 86.03% (Bootstrap). Although no significant differences between the two landscape units were detected (THutchinson=1.59, p=0.81), species diversity was higher in the forested area than in the intervened area. The dominant trophic guild in both landscape units was that of insectivorous birds. No significant differences in bird community trophic structure were found between the two landscape units (X 2 =14.60, p=0.33). The size, shape, or intervention history of the fragments could have resulted in a lack of differences in the structure and composition of the avifauna in the two landscape units.
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MOURÃO, KEILA R. M., VALDIMERE FERREIRA, and FLÁVIA LUCENA-FRÉDOU. "Composition of functional ecological guilds of the fish fauna of the internal sector of the Amazon Estuary, Pará, Brazil." Anais da Academia Brasileira de Ciências 86, no. 4 (2014): 1783–800. http://dx.doi.org/10.1590/0001-3765201420130503.
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The present study describes the spatial and temporal structure of the estuarine fish community in the internal sector of the Amazon Estuary. Samples were obtained in the main channels and tidal creeks of Guajará and Marajó Bays and Guamá River. A total of 41,516 fish specimens were collected, representing 136 taxa, 38 families and 12 orders. In the dry season, the mean salinity of the main channel increased along a limnic-marine gradient, between the Guamá River and the Marajó Bay. Species richness was lowest in the mouth of the Guamá River and in the right margin of the Guajará Bay. Fish species composition and environmental guilds differed markedly among areas: Migrants and Freshwater Stragglers were dominant in the Guamá River and the Guajará Bay, while Estuarine, Marine Stragglers and Migrants predominated in the Marajó Bay. However, the trophic guilds were still relatively well balanced, in functional terms. Piscivores and Zoobenthivores were the dominant feeding functional groups in all the studied areas. In this study, the assessment of the community and the use of the guild approach were efficient to describe the structure and functioning of the assemblages of estuarine fish also helping to assess the anthropogenic pressures in the area.
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Garrison, Lance P. "Spatial and dietary overlap in the Georges Bank groundfish community." Canadian Journal of Fisheries and Aquatic Sciences 57, no. 8 (2000): 1679–91. http://dx.doi.org/10.1139/f00-117.
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Patterns in spatial and trophic resource partitioning in the fish community of the Georges Bank region are identified, accounting for size-based changes in diets. During autumn and spring, this community is divided into geographic assemblages of species that have high spatial overlap. Similarity in spatial distribution is primarily related to similarity in depth preferences, and seasonal differences in species composition within assemblages are related to migrations. There is also important trophic structure within the Georges Bank community separating predators based upon prey size and location in the water column. Ontogenetic changes in diets are an important feature of the trophic structure in this system, particularly in the major piscivores. Seasonal changes in trophic structure reflect both predator and prey migrations. Dietary overlap among predator types is independent of either spatial overlap or depth preferences. There is spatial segregation within trophic guilds, and this spatial partitioning reduces the potential for exploitative competition within this community. Given the observed spatial patterns in trophic structure, the geographic assemblages on Georges Bank may be considered ecologically distinct functional units within this ecosystem.
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Kempf, Hannah L., Ian O. Castro, Ashley A. Dineen, Carrie L. Tyler, and Peter D. Roopnarine. "Comparisons of Late Ordovician ecosystem dynamics before and after the Richmondian invasion reveal consequences of invasive species in benthic marine paleocommunities." Paleobiology 46, no. 3 (2020): 320–36. http://dx.doi.org/10.1017/pab.2020.26.
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AbstractA thorough understanding of how communities respond to extreme changes, such as biotic invasions, is essential to manage ecosystems today. Here we constructed fossil food webs to identify changes in Late Ordovician (Katian) shallow-marine paleocommunity structure and functioning before and after the Richmondian invasion, a well-documented ancient invasion. Food webs were compared using descriptive metrics and cascading extinction on graphs models. Richness at intermediate trophic levels was underrepresented when using only data from the Paleobiology Database relative to museum collections, resulting in a spurious decrease in modeled paleocommunity stability. Therefore, museum collections and field sampling may provide more reliable sources of data for the reconstruction of trophic organization in comparison to online data repositories. The invasion resulted in several changes in ecosystem dynamics. Despite topological similarities between pre- and postinvasion food webs, species loss occurred corresponding to a minor decrease in functional groups. Invaders occupied all of the preinvasion functional guilds, with the exception of four incumbent guilds that were lost and one new guild, corroborating the notion that invaders replace incumbents and fill preexisting niche space. Overall, models exhibited strong resistance to secondary extinction, although the postinvasion community had a lower threshold of collapse and more variable response to perturbation. We interpret these changes in dynamics as a decrease in stability, despite similarities in overall structure. Changes in food web structure and functioning resulting from the invasion suggest that conservation efforts may need to focus on preserving functional diversity if more diverse ecosystems are not inherently more stable.
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Scott, Luke A., and Julie E. Korb. "Birds of the Burn: Avian Community and Functional Guild Variation Five Years Post-Fire in Warm–Dry Mixed Conifer, Southwest Colorado." Fire 7, no. 3 (2024): 62. http://dx.doi.org/10.3390/fire7030062.
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Birds contribute to the trophic interactions within mixed conifer ecosystems and provide a suite of services, such as nutrient transport, seed dispersal, habitat creation, and insect regulation. Avian communities vary in response to the structure and composition of their habitat, which may be drastically altered by fire, the predominant disturbance of western mixed conifer forests. We conducted avian point count surveys during the peak breeding season, five years post-fire, across four burn severities (unburned, low, moderate, and high) within the 416 Fire perimeter, a 55,000-acre mixed-severity fire that burned near Durango, Colorado in 2018. Avian communities in each burn severity were evaluated for richness, diversity, differentiation, indicator species, and functional guild composition. Species assemblages were significantly different across all burn severities, excluding the low to moderate areas comparison, with differentiation driven by live tree and snag density. Avian species’ richness and diversity were not significantly different across burn severities, highlighting the importance of utilizing multivariate community analysis. Unburned and high-burn areas had significant variation in functional guilds and numerous indicator species. This study provides evidence of avian community differentiation by burn severity, suggesting that management practices promoting heterogenous stand structure in warm–dry mixed conifer will positively influence avian biodiversity.
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Tveit, Alexander Tøsdal, Tim Urich, Peter Frenzel, and Mette Marianne Svenning. "Metabolic and trophic interactions modulate methane production by Arctic peat microbiota in response to warming." Proceedings of the National Academy of Sciences 112, no. 19 (2015): E2507—E2516. http://dx.doi.org/10.1073/pnas.1420797112.
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Arctic permafrost soils store large amounts of soil organic carbon (SOC) that could be released into the atmosphere as methane (CH4) in a future warmer climate. How warming affects the complex microbial network decomposing SOC is not understood. We studied CH4production of Arctic peat soil microbiota in anoxic microcosms over a temperature gradient from 1 to 30 °C, combining metatranscriptomic, metagenomic, and targeted metabolic profiling. The CH4production rate at 4 °C was 25% of that at 25 °C and increased rapidly with temperature, driven by fast adaptations of microbial community structure, metabolic network of SOC decomposition, and trophic interactions. Below 7 °C, syntrophic propionate oxidation was the rate-limiting step for CH4production; above this threshold temperature, polysaccharide hydrolysis became rate limiting. This change was associated with a shift within the functional guild for syntrophic propionate oxidation, with Firmicutes being replaced by Bacteroidetes. Correspondingly, there was a shift from the formate- and H2-using Methanobacteriales to Methanomicrobiales and from the acetotrophic Methanosarcinaceae to Methanosaetaceae.Methanogenesis from methylamines, probably stemming from degradation of bacterial cells, became more important with increasing temperature and corresponded with an increased relative abundance of predatory protists of the phylum Cercozoa. We concluded that Arctic peat microbiota responds rapidly to increased temperatures by modulating metabolic and trophic interactions so that CH4is always highly produced: The microbial community adapts through taxonomic shifts, and cascade effects of substrate availability cause replacement of functional guilds and functional changes within taxa.
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Garrison, L. "Fishing effects on spatial distribution and trophic guild structure of the fish community in the Georges Bank region." ICES Journal of Marine Science 57, no. 3 (2000): 723–30. http://dx.doi.org/10.1006/jmsc.2000.0713.
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Moreira, Xoaquín, Kailen A. Mooney, Rafael Zas, and Luis Sampedro. "Bottom-up effects of host-plant species diversity and top-down effects of ants interactively increase plant performance." Proceedings of the Royal Society B: Biological Sciences 279, no. 1746 (2012): 4464–72. http://dx.doi.org/10.1098/rspb.2012.0893.
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While plant diversity is well known to increase primary productivity, whether these bottom-up effects are enhanced by reciprocal top-down effects from the third trophic level is unknown. We studied whether pine tree species diversity, aphid-tending ants and their interaction determined plant performance and arthropod community structure. Plant diversity had a positive effect on aphids, but only in the presence of mutualistic ants, leading to a threefold greater number of both groups in the tri-specific cultures than in monocultures. Plant diversity increased ant abundance not only by increasing aphid number, but also by increasing ant recruitment per aphid. The positive effect of diversity on ants in turn cascaded down to increase plant performance; diversity increased plant growth (but not biomass), and this effect was stronger in the presence of ants. Consequently, bottom-up effects of diversity within the same genus and guild of plants, and top-down effects from the third trophic level (predatory ants), interactively increased plant performance.
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Pinheiro, Hudson T., Agnaldo S. Martins, and Jean-Christophe Joyeux. "The importance of small-scale environment factors to community structure patterns of tropical rocky reef fish." Journal of the Marine Biological Association of the United Kingdom 93, no. 5 (2013): 1175–85. http://dx.doi.org/10.1017/s0025315412001749.
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Understanding the spatial distribution of fish species and fish trophic guilds in reef environments may help improve our knowledge about ecological relationships and therefore favour sound strategies for sampling, coastal management and conservation policy. To verify if small-scale changes are important in forming the fish community structure at a tropical rocky coastal island, we assessed the depth, structural complexity and wave exposure gradients. The community structure changed along all gradients analysed. The trophic guilds found on the sheltered, low and intermediate exposure zones, in the deepest areas and in areas of highest structural complexity showed significant differences when compared with the general assemblage. Rocky reefs, even of narrow (transversal) extension, can show great changes in fish community structure at so small a scale that these changes are generally overlooked. The relationships evidenced between community and environment provide strong support for the importance of considering a wide array of such distinct environmental conditions when determining the structure patterns of the community.
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Pereira, Pedro Henrique Cipresso, Marcus Vinicius Bezerra dos Santos, Daniel Lino Lippi, Pedro Henrique de Paula Silva, and Breno Barros. "Difference in the trophic structure of fish communities between artificial and natural habitats in a tropical estuary." Marine and Freshwater Research 68, no. 3 (2017): 473. http://dx.doi.org/10.1071/mf15326.
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The present study tested the hypothesis that artificial habitats (pier and bridge) harbour different fish trophic guilds compared with natural habitats (mangrove roots) and that the trophic structure of fish communities on estuarine artificial habitats resembles adjacent coral reefs. High-definition cameras were used to survey the fish community associated with the different structures over a 6-month period. Benthos was also analysed following the point intercept method on the different habitats. In the estuary, fish abundance was up to threefold higher and species richness twofold higher on artificial structures compared with the natural habitat. Mangrove roots were mainly inhabited by juvenile carnivores, whereas the pier and bridge were mostly inhabited by sessile invertebrate feeders and roving herbivores. A less diverse benthic community was found on mangrove roots, mostly composed of mud and algae. In contrast, benthos at the bridge and pier was more diverse and dominated by sponges, octocorals and oysters. In addition, fish trophic structure from an adjacent coral reef area showed more than 60% similarity with the fish community on the artificial structures surveyed. The results of the present study indicate that artificial hard structures support unique fish communities compared with natural estuarine mangrove habitats.
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Poiesz, SSH, JIJ Witte, and HW van der Veer. "Only a few key prey species fuel a temperate coastal fish food web." Marine Ecology Progress Series 653 (October 29, 2020): 153–66. http://dx.doi.org/10.3354/meps13472.
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The food web structure of a coastal fish community (western Dutch Wadden Sea) was studied based on stomach content data from samples collected between 2010 and 2018. In total, 54 fish species were caught and 72 different prey items were identified. Fish species consumed from only a few up to >30 different prey species, suggesting the presence of both opportunistic and more specialized feeders. We found no significant differences between years or switches in food source with fish size. The trophic positions of the Wadden Sea fish community ranged from 2.0 to 4.7, with most trophic positions above 3.0. In the past, (near)-resident species were the most abundant guild in spring, and juvenile marine migrants in autumn. At present, all guilds are present in similar but low abundances. The (near)-resident community consisted of about 20 species that fed primarily on amphipod crustaceans, brown shrimps and juvenile herring. There was only a slight overlap in diet with the group of juvenile marine migrants (5 species of juvenile flatfishes and clupeids), whose preferred prey were copepods, polychaetes and brown shrimps. About 15 species of marine seasonal visitors showed an overlap in diet with both the (near)-resident and the juvenile marine migrants, especially for brown shrimps and to a lesser extent herring and gobies. Our results illustrate (1) the pivotal position of a few key prey species (amphipod crustaceans, brown shrimps, juvenile herring and gobies) for the coastal Wadden Sea fishes and (2) that the substantial prey overlap in the diet of some predators cannot exclude intra- and inter-specific competition among these predators.
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Aguirre, Luis F. "STRUCTURE OF A NEOTROPICAL SAVANNA BAT COMMUNITY." Journal of Mammalogy 83, no. 3 (2002): 775–84. https://doi.org/10.5281/zenodo.13475595.
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(Uploaded by Plazi for the Bat Literature Project) During the 5-month dry season, I studied the community structure of bats in the Neotropical savanna of Esp´ıritu, Bolivia. This seasonally inundated, grassland-dominated savanna is inhabited by Ն38 species of bats, and diversity is high (HЈ ϭ 2.88). Species richness is highest in forest islands (26 species), open woodlands and gallery forests (11 species each), and dense thorny bushes (7 species) and less in other plant associations. Although species from almost all trophic guilds filled by New World bats occur in the area, small mediumsize low-flying insectivorous species and medium-to-large fruit-eating bats predominate.
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Aguirre, Luis F. "STRUCTURE OF A NEOTROPICAL SAVANNA BAT COMMUNITY." Journal of Mammalogy 83, no. 3 (2002): 775–84. https://doi.org/10.5281/zenodo.13475595.
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(Uploaded by Plazi for the Bat Literature Project) During the 5-month dry season, I studied the community structure of bats in the Neotropical savanna of Esp´ıritu, Bolivia. This seasonally inundated, grassland-dominated savanna is inhabited by Ն38 species of bats, and diversity is high (HЈ ϭ 2.88). Species richness is highest in forest islands (26 species), open woodlands and gallery forests (11 species each), and dense thorny bushes (7 species) and less in other plant associations. Although species from almost all trophic guilds filled by New World bats occur in the area, small mediumsize low-flying insectivorous species and medium-to-large fruit-eating bats predominate.
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Denys, Luc, and Willem H. De Smet. "Diversity, Composition and Environmental Relations of Periphytic Rotifer Assemblages in Lentic Freshwater Bodies (Flanders, Lower Belgium)." Diversity 15, no. 12 (2023): 1214. http://dx.doi.org/10.3390/d15121214.
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Periphytic rotifer assemblages from lentic habitats are understudied. To improve knowledge on the principal environmental determinants of their structure and composition, we examined summer periphyton from 184 freshwater bodies from a taxonomic and multi-trait-based perspective. Only the latter allowed consideration of all bdelloids. Alpha diversity decreased with electrolyte and aluminium concentration but increased with macrophyte richness, pointing at salinization, metal toxicity and loss of structural niche heterogeneity as potential threats for rotifer diversity. Replacement was the prominent component of beta diversity, with acidified sites showing the highest local contributions. Variation partitioning indicated that local conditions explained variation in species composition best, but general setting (soil type, land cover, connectivity) and spatial context were also not insignificant. Redundancy analysis related species composition more particularly to gradients of pH and trophic status, whereas the representation of functional groups was structured mainly by phytoplankton productivity. Mirroring shifts observed in the plankton, high phytoplankton productivity associated with larger size and more detritibacterivory. Dominance of collectors constrained variation in guild ratios, underlining the need for more refined functional approaches. To aid the use of periphytic rotifers in regional water quality assessment, we identified indicators and community thresholds for pH and trophic variables and determined optima and tolerances for individual taxa.
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Protopapa, Maria, and Soultana Zervoudaki. "Unraveling Zooplankton Trophic Dynamics: Insights from Stable Isotope Analysis in the Eastern Mediterranean (Aegean, Cretan and Ionian Seas)." Water 17, no. 8 (2025): 1187. https://doi.org/10.3390/w17081187.
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Understanding the trophic interactions and community structure of zooplankton is essential for assessing energy transfer in marine ecosystems. This study investigates the spatial and seasonal variations in stable carbon (δ13C) and nitrogen (δ15N) isotopes of dominant mesozooplankton groups across three sub-basins of the Eastern Mediterranean (North Aegean, Cretan, and South Ionian Seas) during two seasonal surveys (October 2014 and May 2015). Zooplankton samples were collected using a WP-2 net and analyzed for taxonomic composition, abundance, biomass, and stable isotopic signatures to assess trophic positioning. The results indicate that copepods dominated the zooplankton community at all stations, with Clausocalanus and Oithona juveniles being the most abundant taxa. Salps contributed significantly at certain stations, reflecting regional variations in the planktonic food web structure. Zooplankton δ15N values exhibited pronounced spatial and seasonal differences, with higher enrichment observed in 2014 compared to 2015. The calculated trophic positions highlight the variability in feeding strategies among copepod species, with Calanus helgolandicus occupying the highest trophic position (TP = 3.34) and Lucicutia spp. the lowest (TP = 1.22). Isotopic niche analysis identified two distinct feeding guilds: a group relying on phytoplankton and microzooplankton and another exhibiting broader trophic plasticity, including omnivorous and carnivorous taxa. These findings underscore the complexity of zooplankton trophic interactions in the Eastern Mediterranean and the role of regional hydrographic conditions in shaping the food web structure. This study provides essential baseline data for future research on the impacts of climate change and nutrient variability on Mediterranean marine ecosystems.
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Roth, Steffen, and James G. Wilson. "Functional analysis by trophic guilds of macrobenthic community structure in Dublin Bay, Ireland." Journal of Experimental Marine Biology and Ecology 222, no. 1-2 (1998): 195–217. http://dx.doi.org/10.1016/s0022-0981(97)00145-7.
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Ortiz, Vilma, Sinead Phelan, and Ewen Mullins. "A temporal assessment of nematode community structure and diversity in the rhizosphere of cisgenic Phytophthora infestans-resistant potatoes." BMC Ecology 16, no. 1 (2016): 55. https://doi.org/10.1186/s12898-016-0109-5.
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<strong>Background: </strong>Nematodes play a key role in soil processes with alterations in the nematode community structure having the potential to considerably influence ecosystem functioning. As a result fluctuations in nematode diversity and/or community structure can be gauged as a 'barometer' of a soil's functional biodiversity. However, a deficit exists in regards to baseline knowledge and on the impact of specific GM crops on soil nematode populations and in particular in regard to the impact of GM potatoes on the diversity of nematode populations in the rhizosphere. The goal of this project was to begin to address this knowledge gap in regards to a GM potato line, cisgenically engineered for resistance to <i>Phytophthora infestans</i> (responsible organism of the Irish potato famine causing late blight disease). For this, a 3 year (2013, 2014, 2015) field experimental study was completed, containing two conventional genotypes (cvs. Desiree and Sarpo Mira) and a cisgenic genotype (cv. Desiree + <i>Rpi</i>-<i>vnt1</i>). Each potato genotype was treated with different disease management strategies (weekly chemical applications and corresponding no spray control). Hence affording the opportunity to investigate the temporal impact of potato genotype, disease management strategy (and their interaction) on the potato rhizosphere nematode community.<strong>Results: </strong>Nematode structure and diversity were measured through established indices, accounts and taxonomy with factors recording a significant effect limited to the climatic conditions across the three seasons of the study and chemical applications associated with the selected disease management strategy. Based on the metrics studied, the cultivation of the cisgenic potato genotype exerted no significant effect (P > 0.05) on nematode community diversity or structure. The disease management treatments led to a reduction of specific trophic groups (e.g. Predacious c–p = 4), which of interest appeared to be counteracted by a potato genotype with vigorous growth phenotype e.g. cv. Sarpo Mira. The fluctuating climates led to disparate conditions, with enrichment conditions (bacterial feeding c–p = 1) dominating during the wet seasons of 2014 and 2015 versus the dry season of 2013 which induced an environmental stress (functional guild c–p = 2) on nematode communities.<strong>Conclusions: </strong>Overall the functional guild indices in comparison to other indices or absolutes values, delivered the most accurate quantitative measurement with which to determine the occurrence of a specific disturbance relative to the cultivation of the studied cisgenic <i>P. infestans</i>-resistant potatoes.
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Huang, I.-Yu, Yao-Sung Lin, Chang-Po Chen, and Hwey-Lian Hsieh. "Food web structure of a subtropical headwater stream." Marine and Freshwater Research 58, no. 7 (2007): 596. http://dx.doi.org/10.1071/mf06127.
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The food web structure of a headwater stream (Hapen Creek) in subtropical northern Taiwan, which is subject to regular typhoon disturbances, was characterised using stable isotope techniques. δ13C and δ15N signatures were used to examine (i) the relative contributions of allochthonous versus. autochthonous sources to the web, and (ii) the trophic organisation of the community including the predominant feeding guilds and the most prevalent feeding mode. This study presents food web attributes for one of the very few food webs studied to date in a subtropical region. Consumers utilised allochthonous and autochthonous carbon sources differently depending on their trophic positions. The majority of consumers exploited more autochthonous carbon sources. Consumers at higher trophic positions in the food web had more direct and greater association with benthic algae. Higher-order consumers also consumed allochthonous carbon in an indirect manner by assimilating lower-order insects. The results reveal the importance of invertebrate consumer snails and aquatic insects in the transfer of organic matter. Omnivores predominated in the food web; this may reflect an opportunistic foraging strategy that enables them to adapt to hydrological disturbances and a fluctuating food supply.
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Gao, Shike, Bin Xie, Yufeng He, et al. "Trophic Structure of Fish Community in Artificial Reef Ecosystem Based on Body Mass Using Stable Isotope." Water 16, no. 21 (2024): 3034. http://dx.doi.org/10.3390/w16213034.
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Artificial reefs are widely recognized for their role in improving the ecological environment and creating protected habitats for marine organisms, ultimately enhancing biodiversity within the food web and fisheries resources. This study utilizes stable isotopes to analyze fish samples ranging from 3.4 to 1067 g in body mass, collected within the artificial reef area of Haizhou Bay. The objective is to determine if the δ15N-based fish body mass acts as a driving factor in shaping the food web structure. The results showed a certain level of overlap among all trophic guilds, suggesting that most trophic guilds within this region share similar living environments and feeding habits. The multiple linear regression showed a slight increasing trend between δ15N values and body mass. Furthermore, the predator–prey mass ratio (PPMR) was calculated to be 430:1 based on the δ15N–body mass relationship. This implies that larger reef fish within this artificial reef ecosystem tend to have higher δ15N values compared to smaller fish, indicating a shorter food chain in this ecosystem. In summary, this analysis provides valuable insights into the fish community structure within artificial reef ecosystems. Therefore, it is recommended that future studies focus on further characterizing the fish community structure using body mass information.
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Ivanovskij, V. V., A. A. Sidorovich, and I. A. Solovej. "Changes in the Trophic Structure of the Vertebrate Predator Community in the Cold Season in Belarussian Paazerje (Northern Belarus) in Relation with Emphasis on Depopulation of the Wild Boar, Sus scrofa (Artiodactyla, Suida)." Zoodiversity 55, no. 2 (2021): 133–42. http://dx.doi.org/10.15407/zoo2021.02.133.
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Anthropogenic disturbances often alter patterns of community functioning. Along that, how interacting species respond to these changes remains poorly understood. In 1972–2019, we studied the trophic structure of the vertebrate predator community in coniferous-small-leaved forests of Belarussian Paazerje (Northern Belarus). Since 2013, large scale depopulation of wild boars Sus scrofa has been started in Belarus as a measure to reduce a circulation of the African swine fever (ASF). It was found that the community consisted of four trophic guilds including small rodent consumers, bird consumers, scavengers, and ungulate consumers. The pronounced shifts in dietary compositions of three scavengers (the raccoon dog Nyctereutes procyonoides, golden eagle Aquila chrysaetos and white-tailed eagle Haliaeetus albicilla) after a decrease in an abundance of wild boar carrion was revealed. Along that, the average value of the dietary similarity between investigated species stayed the same.
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Protasov, Alexander. "Species from the viewpoint of biocoenology." Novitates Theriologicae, no. 12 (June 6, 2021): 86–96. http://dx.doi.org/10.53452/nt1217.
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Some questions of the use of the “species” concept in biocoenology and hydrobiology are considered. The existence of certain difficulties and ambiguities in the use of this concept is shown. It is proposed to clarify the goals and objectives of identifying the species structure of biocoenoses. The examples show that ecomorphs and coeno-ecomorphs are not less important elements of a biocenotic system and require thorough research. The question of the possibility and feasibility of definitions "to species level" of all members of the community is considered. The ecological niche concept is associated with species, although there is also the guild concept that unites species according to the principle of convergent similarity of trophic, topical, or other preferences. Various systems of bioindication have become widespread, which are based on the principle of compliance of a particular species population to certain conditions. First of all, we are talking about disturbed conditions, including various impacts by pollution. It was shown that not only species, but also more easily identifiable higher taxa could be used as bioindicators of certain conditions.
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Yang, Nan, Yuchao Wang, Boran Liu, et al. "Exploration of Soil Microbial Diversity and Community Structure along Mid-Subtropical Elevation Gradients in Southeast China." Forests 14, no. 4 (2023): 769. http://dx.doi.org/10.3390/f14040769.
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Climate change is altering the abundance and distributions of natural communities in mountainous ecosystems, but the variations of soil microbial communities and their driving factors along elevation gradients at high altitudinal mid-subtropical zones have received limited attention. Such information is needed for a comprehensive understanding of the ecosystem’s response to intensifying climate changes. In this study, using Illumina sequencing, we investigated the shift in soil microbial diversity and community composition at eight evergreen broadleaf forest sites, which ranged from a low of 550 to a high of 1038 m above sea level (m a.s.l.) on Wuyi Mountain in Southeast China. Significant (p < 0.05) differences were observed only in the community structure of bacteria and fungi between the low and high elevation levels of forests, but not in their alpha-diversity indices. Soil bacterial diversity was significantly correlated with plant Shannon index. Likewise, plant richness and diversity modified soil bacterial community structures along the two elevations and were the best predictors. Soil pH was the main edaphic factor driving the fungal diversity across elevations, whereas inconsistency in the fungal trophic mode did not allow the identification of a determinant factor for soil fungal community structure. The variations of the predominant fungal trophic guilds, such as the symbiotrophs and pathotrophs, along elevation gradients were due to the plant richness and diversity prevailing at the low and high elevation levels of forest sites. The findings of this study reveal the soil microbial community dynamics and the local regulators across elevations on Wuyi mountain.
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Pereira, Poliana Ribeiro, Carlos Sérgio Agostinho, Rafael José de Oliveira, and Elineide Eugênio Marques. "Trophic guilds of fishes in sandbank habitats of a Neotropical river." Neotropical Ichthyology 5, no. 3 (2007): 399–404. http://dx.doi.org/10.1590/s1679-62252007000300019.
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The objective of this study was to characterize the trophic structure of the community of fishes exploiting riverine sandbank habitats. Collections were carried out during the period of October 1999 to December 2003, on six sand banks in the upper and middle portions of the Tocantins River drainage basin in central Brazil. The availability of food resources was evaluated based on the volume of the items present in the stomachs of all species. A total of 2,127 stomachs of fish belonging to 50 species were analyzed. Nine main trophic guilds grouped the local ichthyofauna according to diet. Aquatic-origin items were the preferred source for 55.5% of the groups analyzed, whereas terrestrial-origin items composed 44.4%. Items of undetermined origin (detritus and sediment), although present in 89% of the guilds, were the predominant food in only one trophic group. Terrestrial insects and fish were the food sources with the largest biomass available in the environment. Sandbank environments are homogeneous, with little shelter and food available; as a rule, the species that occupy these environments are generalists.
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Amarillo-Suárez, Angela R., Mariana Camacho-Erazo, and Henri W. Herrera. "Land use is a stronger determinant of ecological network complexity than the number of trophic levels." PLOS ONE 19, no. 2 (2024): e0295377. http://dx.doi.org/10.1371/journal.pone.0295377.
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Land modification causes biodiversity loss and ecosystem modification. Despite many studies on the impacts of this factor, there is little empirical evidence on how it affects the interaction networks of plants, herbivores and their natural enemies; likewise, there is little evidence on how those networks change due to differences in the complexity of the communities they comprise. We analyzed the effects of land use and number of trophic levels on the interaction networks of exotic legume species and their associated arthropods. We collected seedpods from five exotic legume species (one of them invasive) in four land use types (urbanization, roadside, L. leucocephala plantation, wooded pasture) on Santa Cruz Island in the Galapagos, and obtained all arthropods that emerged from the seeds. Then, we built and analyzed the interaction networks for each land use at two community scales, each with different numbers of trophic levels: (1) three levels: plant-seed beetle-parasitoid (PSP), and (2) more than three levels: plant-seed beetle-parasitoid-predator and other trophic guilds (PSPP). Land use was more relevant than number of trophic levels in the configuration of species interactions. The number of species and interactions was highest on roadsides at PSPP and lowest in plantations at PSP. We found a significant effect of land use on connectance and interaction evenness (IE), and no significant effect of number of trophic levels on connectance, diversity or IE. The simultaneous analysis of land use and number of trophic levels enabled the identification of more complex patterns of community structure. Comparison of the patterns we found among islands and between exotic and native legumes is recommended. Understanding the structure of the communities analyzed here, as well as the relative contribution of their determinants of change, would allow us to develop conservation plans according to the dynamics of these neo-ecosystems.
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Muñoz-Sáez, Andrés. "Vineyard Edges Increase Bird Richness and Abundance and Conservation Opportunities in Central Chile." Agriculture 14, no. 12 (2024): 2098. http://dx.doi.org/10.3390/agriculture14122098.
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Agricultural landscapes significantly impact biodiversity, particularly within vineyard ecosystems where the configuration of native vegetation and vineyard edges plays a pivotal role. This study investigated the structure of bird communities across vineyards, their edges, and adjacent native vegetation, utilizing generalized linear mixed models to analyze the influence of surrounding land covers at varying scales of 100 m and 1000 m radii across these three landscape types on bird richness and abundance and functional groups. The results highlight that native vegetation is crucial for supporting endemic bird species, with 41% of all observed species found across all three habitat types and a significant 66.7% shared between native vegetation and edge habitats. In particular, insectivores and carnivores, key to biodiversity conservation and ecosystem service provision, showed higher abundances in areas with extensive native vegetation, underscoring its vital role in maintaining ecological functions. Edges not only enhanced the general bird richness and abundance but also served as crucial habitats for granivores and omnivores, influencing ecosystem dynamics through changes in the trophic guild community structure. These findings underscore the importance of conserving native vegetation within vineyard landscapes to foster a diverse avian community that contributes to enhancing ecosystem services. These results provide an opportunity to intensify restoration initiatives on vineyard edges and enhance our understanding of how certain species adapt to agriculture. This can be considered a vital nature-based solution for sustainable agriculture, promoting biodiversity conservation alongside productive agroecological practices in vineyard ecosystems.
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Yamazaki, Lúcia, Juliana Dambroz, Eliandra Meurer, et al. "Ant community (Hymenoptera: Formicidae) associated with Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) canopies in the Pantanal of Poconé, Mato Grosso, Brazil." Sociobiology 63, no. 2 (2016): 735. http://dx.doi.org/10.13102/sociobiology.v63i2.824.
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Ants act in different trophic levels and are important due to their abundance, distribution and diversity in a variety of habitats, exercising influence on many different organisms and ecosystems. Thus, this study compared temporal variation on the structure and composition of the Formicidae community in canopies of Callisthene fasciculata (Spr.) Mart. (Vochysiaceae) during high water and dry periods, in the Pantanal of Poconé, Mato Grosso, Brazil. Ant sampling was performed on 12 specimens of C. fasciculata, in 2010 and 2011, using canopy fogging with insecticide, in a total of 120m² of sampled canopy. Altogether, 2,958 ants were collected. The 2,943 adults were distributed in four subfamilies, 12 genus and 26 species. Myrmicinae (18.7 ind./m2) was the most representative taxon, followed by Formicinae (3.2 ind./m2), Dolichoderinae (2.2 ind./m2) and Pseudomyrmecinae (0.3 ind./m2). The community is made up of six trophic groups, in which omnivorous (23.5 ind./m2) were the most prevalent, followed by minimum hypogeical generalists (0.5 ind./m2) and arboreal generalist predators (0.3 ind./m2). Although the results showed that Formicidae community richness, associated to C. fasciculata canopies, does not represent a significant difference among the seasonal periods, there are differences as to species distribution and grouping in trophic guilds on the host plant over the seasonal periods, indicating the influence of temporal variation, and therefore, habitat conditions on this community.
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Albuquerque, Tiago, Miguel Loiola, José de Anchieta C. C. Nunes, José Amorim Reis-Filho, Cláudio L. S. Sampaio, and Antoine O. H. C. Leduc. "In situ effects of human disturbances on coral reef-fish assemblage structure: temporary and persisting changes are reflected as a result of intensive tourism." Marine and Freshwater Research 66, no. 1 (2015): 23. http://dx.doi.org/10.1071/mf13185.
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Non-lethal human disturbances are often drivers of change in animal population and community structure. To gauge their severity, short-term behaviour (e.g. avoidance and habituation) has been argued to be a sensitive measure. However, many of these behavioural changes may occur only if disturbance-free habitat is readily accessible. In coral-reef fish, we tested whether human disturbances from intensive (i.e. loud music, swimming, snorkelling, splashing and fish feeding by numerous visitors) tourist visitations resulted in assemblage structure shifts led by short-term behaviour. We monitored fish assemblage before, during and after tourist visitations to monitor changes associated with behaviour. Additionally, we monitored two adjacent reefs not visited by tourists because of difficult approach by boat. We posited that if short-term benefits of relocating to disturbance-free habitat outweigh the costs of tolerating disturbances, fish assemblage structure should shift along with tourist visitation levels. By contrast, if sensitive species are unable or unwilling to relocate, we predicted greater levels of assemblage heterogeneity between the visited and control reefs. Our results showed that in situ human visitations led to significant shifts in assemblage structure, resulting from short-term behavioural changes. Additionally, we showed significant between-reefs differences, whereby control reefs were characterised by higher species richness, larger fish sizes and variations in relative trophic guild prevalence. Our results suggest that short-term relocations to adjacent disturbance-free reefs may not mitigate the effects of human disturbances.
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Box, Antonio, Daniel Martin, and Salud Deudero. "Changes in seagrass polychaete assemblages after invasion by Caulerpa racemosa var. cylindracea (Chlorophyta: Caulerpales): community structure, trophic guilds and taxonomic distinctness." Scientia Marina 74, no. 2 (2010): 317–29. http://dx.doi.org/10.3989/scimar.2010.74n2317.
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Mamun, Md, Namsrai Jargal, Usman Atique, and Kwang-Guk An. "Ecological River Health Assessment Using Multi-Metric Models in an Asian Temperate Region with Land Use/Land Cover as the Primary Factor Regulating Nutrients, Organic Matter, and Fish Composition." International Journal of Environmental Research and Public Health 19, no. 15 (2022): 9305. http://dx.doi.org/10.3390/ijerph19159305.
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This study was performed to determine the ecological health of a temperate river over nine years (2011–2019); it also analyzed the trophic structure and linkage of nutrients (nitrogen [N] and phosphorus [P]), sestonic chlorophyll-a (CHL-a), and the top trophic fish in the Asian monsoon region. Water chemistry, trophic indicators, and tolerance guilds were primarily influenced by land use and land cover (LULC); the magnitude of variation was also related to geographic elevation, artificial physical barriers (weirs), and point sources. Levels of nutrients, organic matter, and CHL-a largely influenced by the intensity of the monsoon seasonality for a particular LULC and stream order. Mann–Kendall tests based on a long-term annual dataset showed that annual organic matter and CHL-a increased over time because of longer hydraulic residence time after weir construction. The results of empirical nutrient models suggested that P was the key determinant for algal growth (CHL-a); the strong P-limitation was supported by N:P ratios > 17 in ambient waters. Linear regression models and canonical correspondence analysis (CCA) were used to determine the influences of LULC and water quality on the trophic/tolerance linkages, fish community compositions and structures, and river health. Tolerant species had a positive functional relationship with nutrient enrichment through total phosphorus (TP) (R2 = 0.55, p < 0.05) and total nitrogen (TN) (R2 = 0.57, p < 0.05), organic pollution in terms of biological oxygen demand (BOD) (R2 = 0.41, p < 0.05) and chemical oxygen demand (COD) (R2 = 0.49, p < 0.05), and algal growth (R2 = 0.47, p < 0.05); sensitive species exhibited the opposite pattern. The degradation of river health, based on the multi-metric index of biotic integrity (IBI) model, was evident in the downriver region (“fair–poor” condition) and was supported by the quantitative fish community index (QFCI) model. The outcomes suggested that the degradation and variation of ecological river health, trophic linkages of water chemistry (N, P)-algal biomass-fish, were largely controlled by the land use pattern and construction of physical barriers in relation to the Asian monsoon.
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Vanhove, S., H. J. Lee, M. Beghyn, D. Van Gansbeke, S. Brockington, and M. Vincx. "The Metazoan Meiofauna in Its Biogeochemical Environment: The Case of an Antarctic Coastal Sediment." Journal of the Marine Biological Association of the United Kingdom 78, no. 2 (1998): 411–34. http://dx.doi.org/10.1017/s0025315400041539.
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The metazoan meiobenthos was investigated in an Antarctic coastal sediment (Factory Cove, Signy Island, Antarctica). The fine sands contained much higher abundances compared to major sublittoral sediments worldwide. Classified second after Narrangansett Bay (North Atlantic) they reached numbers of 13 × 106ind m-2. The meiofauna was highly abundant in the surface layers, but densities decreased sharply below 2 cm. Vertical profiles mirrored steep gradients of microbiota, chloropigments and organic matter and were coincident with chemical stratification. Spatial patchiness manifested especially in the surface layer. Nematodes dominated (up to 90%), andAponema, Chromctdorita, Diplolaimella, Daptonema, MicrolaimusandNeochromadoraconstituted almost the entire community. Overall, the nematode fauna showed a strong similarity with fine sand communities elsewhere. The dominant trophic strategies were epistrarum and non-selective deposit feeding, but the applied classification for feeding guild structure of the nematodes of Factory Cove is discussed. High standing stock, low diversity and shallow depth distribution may have occurred because of the high nutritive (chlorophyll exceeded lOOOmgm-2and constituted almost 50% of the organic pool) and reductive character of the benthic environment. These observations must have originated from the substantial input of fresh organic matter from phytoplankton and microphytobenthic production, typical for an Antarctic coastal ecosystem during the austral summer.
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Bhusal, Daya Ram, Athanasios S. Kallimanis, Maria A. Tsiafouli, and Stefanos P. Sgardelis. "Higher taxa vs. functional guilds vs. trophic groups as indicators of soil nematode diversity and community structure." Ecological Indicators 41 (June 2014): 25–29. http://dx.doi.org/10.1016/j.ecolind.2014.01.019.
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Novakowski, Gisele Caroline, Norma Segatti Hahn, and Rosemara Fugi. "Diet seasonality and food overlap of the fish assemblage in a pantanal pond." Neotropical Ichthyology 6, no. 4 (2008): 567–76. http://dx.doi.org/10.1590/s1679-62252008000400004.
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We assessed the trophic structure of the fish fauna in Sinhá Mariana pond, Mato Grosso State, from March 2000 to February 2001. The aim was to determine the feeding patterns of the fish species during the rainy and dry seasons. The diets of 26 species (1,294 stomach contents) were determined by the volumetric method. Insects and fish were the most important food resources: insects were the dominant food of 23% and 27% of the species, respectively, in the rainy and dry season, and fish was the dominant item for 31% of the species in both seasons. Cluster analysis (Euclidean Distance) identified seven trophic guilds in the rainy season (detritivores, herbivores, insectivores, lepidophages, omnivores, piscivores and planktivores), and five trophic guilds in the dry season (detritivores, insectivores, lepidophages, omnivores and piscivores). The smallest mean values of diet breadth were observed for the specialist guilds (detritivores, lepidophages and piscivores), in both seasons. The widest means for diet breadth were observed for the omnivores, regardless of the season. In general, there was no seasonal variation in feeding overlap among the species studied. At the community level, diet overlap values between species were low (< 0.4) for 80% of the pairs in each season, suggesting wide partitioning of the food resource. The fish assemblage showed a tendency toward trophic specialization, regardless of the season, although several species changed their diets. We might consider two non-excludent hypothesis: that there is no pattern on the use of seasonal food resources and/or probably there are several patterns, because each one is based on characteristics of the studied site and the taxonomic composition of the resident species.
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AJERRAR, Abdelhadi, Mina ZAAFRANI, Redouan QESSAOUI, et al. "Diversity and abundance of insect’s community associated to Argania spinosa (L.) Skeels foliage." Notulae Scientia Biologicae 16, no. 1 (2024): 11594. http://dx.doi.org/10.55779/nsb16111594.
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Argan tree (Argania spinosa) is the unique representative of Sapotaceae family in North-Africa. This family is commonly growing in pantropical areas. The current study focused on the diversity of foliage insect associated to A. spinosa, and their seasonality in four sites in Souss region. Insects were trapped using sticky yellow traps installed on each sampled Argan tree. Consequently, 241 morphospecies were identified represented by seven orders. Hemiptera was the most abundant, followed by Diptera and Hymenoptera. However, the remains orders represented only less than 4%. A high taxonomic richness was recorded for Hymenoptera (100 morphospecies) followed by Diptera (70) and Coleoptera (39). Data analysis shows a quantitative dominance of some insects’ families. Within Hemiptera, Aleyrodidae represented up to 80% of total captures. Coccinellidea was the most abundant family of Coleoptera representing over 62%. Among Diptera and Hymenoptera, more than 60% of total abundance was represented only by five families. Argan foliage insects exhibited seasonal variations. Therefore, high significant diversity parameters were recorded during spring. However, the lowest diversity was recorded during summer in Belfaa and during autumn for the other sites. Five trophic guilds were reported. Their abundance was influenced by seasonal variation. Herbivores abundance was highly significant compared to the others trophic guilds throughout all sampling seasons. Except Ceratitis capitata Wiedemann, which infests argan fruits during the two latest stages of maturity, none of its herbivores is known as economic interest to the argan tree. On the other hand, argan trees host a complex structure of functional taxa, including pest regulating (predators and parasitoids) and pollinators.
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Naka, Luciano Nicolás. "Structure and Organization of Canopy Bird Assemblages in Central Amazonia." Auk 121, no. 1 (2004): 88–102. http://dx.doi.org/10.1093/auk/121.1.88.
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AbstractI analyzed the species composition, structure, and trophic organization of bird assemblages in the forest canopy around Manaus, Brazil. Using three canopy towers located in primary terra firme forests, I conducted 117 censuses over a 13 month period, recording 160 bird species. The three study sites had similar species richness (between 126 and 128 species), sharing 95 species in common, which accounted for >90% of all individual records. Most species recorded in the canopy (110) belonged to the core canopy avifauna. The other 50 species included migrants (13), species that feed overhead (8), species from lower strata (15), night birds (3), and vagrants or visitors from open areas and second-growth forests (11). Most of those species, however, appeared in very low numbers in the forest canopy, except understory frugivores, which regularly fed on canopy fruits. Among the migratory species were some Nearctic (6), Austral (3), and species probably holding both migratory and resident populations in the area (4). Additionally, I found evidence that two species of parrots perform seasonal movements, leaving the forest canopy around Manaus during the dry season. Frugivores dominated the canopy avifauna in abundance, but contradicting results reported from other Neotropical forest canopies, insectivores and frugivores had equal species richness. The canopy avifauna was highly homogeneous among sites in terms of species richness, distribution among abundance classes, and number of species in each feeding guild, habitat, and microhabitat. As in Costa Rica, the canopy avifauna of Manaus was mostly composed by typical canopy bird species, and not by edge-living species as reported from Panama. I suggest that habitat fragmentation may affect the bird community composition in the forest canopy, allowing a higher influx of opportunistic species.
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Fu, Ziqi, Qin Chen, Pifeng Lei, Wenhua Xiang, Shuai Ouyang, and Liang Chen. "Soil Fungal Communities and Enzyme Activities along Local Tree Species Diversity Gradient in Subtropical Evergreen Forest." Forests 12, no. 10 (2021): 1321. http://dx.doi.org/10.3390/f12101321.
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The majority of studies have found that an increase in tree species diversity can increase the productivity of forest stands thanks to complimentary effects with enhanced resource use efficiency or selection effects; however, it is unclear how tree species diversity affects the soil fungal community and enzyme activities in subtropical evergreen forests. In this study, we used soil high-throughput sequencing to investigate the soil fungal community structure and diversity in the central area of tree clusters in the gradient of tree species richness formed by four possible dominant tree species (Pinus massoniana Lamb., Choerospondias axillaris Roxb., Cyclobalanopsis glauca Thunb. and Lithocarpus glaber Thunb.) in subtropical evergreen broad-leaved forest. The results showed that soil organic carbon content and total nitrogen content were significantly higher in mixed tree clusters, and that soil fungal richness and diversity increased with the increase in tree species diversity (1–3 species). Soil acid phosphatase and urease activity were also enhanced with tree species diversity (p < 0.05). The relative abundance of soil symbiotic fungi (ectomycorrhizal fungi) decreased, while the relative abundance of saprotrophic fungi increased. Redundancy analysis (RDA) revealed that soil acid phosphatase activity was the main factor affecting soil fungal communities and functional guilds, and that soil water content was the main driving force behind fungal trophic modes. In subtropical forests, changes in tree species diversity have altered the soil fungal community structure and trophic modes and functions, accelerating the decomposition of organic matter, increasing nutrient cycling, and perhaps also changing the nutrient absorption of trees.