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Kiwifruit, Actinidia spp., is an important crop worldwide and its cultivation has been increasing in Portugal. Kiwifruit plants are susceptible to plant‐parasitic nematodes (PPNs), including Meloidogyne spp. M. hapla and M. incognita have been reported to affect kiwifruit in major production regions worldwide, although information is lacking on the distribution and identity of PPNs associated with kiwifruit orchards in Portugal. Moreover, research is scarce on the drivers of PPN communities in this crop. Our primary objective was to investigate the diversity, density and distribution of PPNs within kiwifruit orchards of Portugal and to elucidate the influence of environmental factors on their community composition. Additionally, we aimed to evaluate population densities and identity of Meloidogyne spp. Nematodes were extracted from composite soil and root samples collected from orchards. Analysis of soil nematode communities suggested bacterial‐driven decomposition and high nutrient enrichment in these soils. Sixteen different genera of PPNs were detected, with Meloidogyne spp. as the dominant genus, mostly represented by a single species, M. hapla. PPN communities exhibited low richness, and β‐diversity analysis indicated a high degree of similarity among them. Additionally, their composition was significantly influenced by soil and climatic parameters. We found that 37 out of 40 kiwifruit orchards in Portugal were infested by root‐knot nematodes. The unexpectedly low species diversity, dominated by M. hapla, merits further research to establish underlying factors for its high incidence in this crop and to assess the impact of these nematodes on kiwifruit performance and productivity. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ecology & Rural Environment is the property of Journal of Ecology & Rural Environment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tree pathogens threaten the survival of many forest foundation tree species worldwide. However, there is limited knowledge of how dieback of foundation tree species may threaten other components of forest ecosystems, such as soil biodiversity and associated ecosystem functions. Kauri (Agathis australis), threatened by the root-borne pathogen Phytophthora agathidicida, are culturally and ecologically significant tree species that exert great influence on soil properties. We aimed to characterise soil mesofauna community structure and energy fluxes in kauri forests and assess the potential threat that tree pathogens such as P. agathidicida pose to belowground ecosystems. We sampled soil mesofauna communities and identified specimens to functional feeding groups at 24 pairs of kauri and adjacent broadleaf trees in sites across the Waitakere Ranges Regional Park, Aotearoa -- New Zealand. We attributed kauri canopy health scores, measured tree diameter, slope, forest floor depth, and soil carbon dioxide efflux. We also analysed soil samples for P. agathidicida presence, total carbon, and total nitrogen. We constructed soil mesofauna food webs associated with kauri and broadleaf trees, and assessed the uniqueness of food webs associated with kauri and the impacts of P. agathidicida on density, biomass, mean body mass, and energy fluxes of mesofauna taxonomic and trophic groups. We found omnivores with larger body mass at kauri where P. agathidicida was detected (i.e., P. agathidicida-positive soils). Compared to broadleaf trees, mesofauna density and biomass were lower in soils under kauri, and body masses of Symphyla and omnivores were smaller in soils under kauri. Differences in mesofauna community response variables between tree types were mainly modulated by the soil C:N ratio, which had positive effects under broadleaf and neutral to negative effects under kauri. Energy fluxes to detritivores and fungivores were greater under larger trees, regardless of tree type or P. agathidicida detection status. Our findings suggest that kauri support soil mesofauna food webs that are distinctly different from those found under broadleaf trees in the same habitat. A decreased presence of this foundation species may be linked to future impacts on soil mesofauna in this forest ecosystem with increasingly advanced stages of kauri dieback. [ABSTRACT FROM AUTHOR]

Analyses of feeding patterns of fish assemblages, common approaches for understanding their habitat use and habitat dependence, have been conducted infrequently in Japanese estuarine salt marshes. The present study, based on gut content analyses, revealed the food habits of fishes occurring in salt marsh estuaries in high- and low-salinity rivers with different sediment conditions (sandy mud and muddy bottoms) in the western Seto Inland Sea, Japan. Ontogenetic changes in food preference were recognized in six species (Lateolabrax japonicus, Acanthogobius flavimanus, Glossogobius olivaceus, Platycephalus sp. 2, Acanthopagrus latus and Gymnogobius breunigii) out of 22 species examined, small individuals generally feeding on calanoid and harpacticoid copepods, and terrestrial and aquatic insects, but subsequently switching to other larger prey items (e.g., crabs, shrimps, and fishes) with growth. A cluster analysis based on dietary overlaps showed that the fish assemblages of the two salt marshes comprised nine trophic groups (zooplankton, small crustacean, large crustacean, polychaete, mollusk, fish, insect, detritus, and plant feeders), large crustacean feeders being the most abundant, followed by fish feeders, compared with polychaete and mollusk feeders, represented by only two and one species, respectively. The most important food items for the overall assemblage comprised shrimps, fishes and detritus, represented by high gut volumes in all fishes and high consumption frequencies. Furthermore, the trophic structures of fish assemblages and important food items varied between the rivers, polychaete and insect feeders being more abundant, with increasing the consumption of their main food items in the low-salinity and muddy river. Some fishes also showed remarkably different diets between adjacent rivers, highlighting small spatial scale variations in food-use patterns of fishes at the community and species levels in salt marsh estuaries. [ABSTRACT FROM AUTHOR]

Long-term application of chemical fertilizer poses an environmental threat to belowground ecosystems. However, the impact of nitrogen (N) or phosphorus (P) fertilizers on soil biodiversity and the conditions of soil food web remains largely unknown. Soil nematodes are the most abundant multicellular soil animals and serve as excellent bioindicators of soil. Here, we investigated soil nematode communities and food web structure in a long-term experiment with different application rates of N and P fertilizers in northeast China. The application of N and P fertilizers increased the abundance of bacterivores but suppressed the abundance of omnivores and predators. The abundance of bacterivores exhibited an increasing trend, while that of omnivores and predators showed a decreasing trend with increasing rates of N and P fertilizers. Plant parasites displayed a decreasing trend in response to N fertilizer, but not to P fertilizer. N and P fertilizers also altered nematode functional guild composition, with N fertilizer increasing the abundance of Ba1, and P fertilizer increasing the abundance of Fu2 and Ba3. Nonmetric multidimensional scaling (NMDS) analysis revealed apparent successions of nematode communities from no fertilizer soils to high rates of N or P fertilizer soils at both the genus and functional guild levels. Furthermore, N and P fertilizers resulted in different nematode communities. In terms of nematode food web indices, N fertilizer increased the enrichment index (EI) but reduced the channel index (CI) and structure index (SI), whereas P fertilizer only reduced the SI value. High rates of N and P fertilizers increased the respired carbon of bacterivores but reduced the respired carbon of predators. Mantel tests revealed significant correlations between soil properties and the community composition of both fungivores and omnivores. Among all soil properties, available phosphorus (AP) had the greatest influence on the community structure of soil nematodes. Our findings indicate that N fertilizer has a powerful effect on nematode food web structure, while P fertilizer exerts a stronger effect on soil nematode community composition. [ABSTRACT FROM AUTHOR]

Tree pathogens threaten the survival of many forest foundation tree species worldwide. However, there is limited knowledge of how dieback of foundation tree species may threaten other components of forest ecosystems, such as soil biodiversity and associated ecosystem functions. Kauri (Agathis australis), threatened by the root-borne pathogen Phytophthora agathidicida, are culturally and ecologically significant tree species that exert great influence on soil properties. We aimed to characterise soil mesofauna community structure and energy fluxes in kauri forests and assess the potential threat that tree pathogens such as P. agathidicida pose to belowground ecosystems. We sampled soil mesofauna communities and identified specimens to functional feeding groups at 24 pairs of kauri and adjacent broadleaf trees in sites across the Waitākere Ranges Regional Park, Aotearoa – New Zealand. We attributed kauri canopy health scores, measured tree diameter, slope, forest floor depth, and soil carbon dioxide efflux. We also analysed soil samples for P. agathidicida presence, total carbon, and total nitrogen. We constructed soil mesofauna food webs associated with kauri and broadleaf trees, and assessed the uniqueness of food webs associated with kauri and the impacts of P. agathidicida on density, biomass, mean body mass, and energy fluxes of mesofauna taxonomic and trophic groups. We found omnivores with larger body mass at kauri where P. agathidicida was detected (i.e., P. agathidicida-positive soils). Compared to broadleaf trees, mesofauna density and biomass were lower in soils under kauri, and body masses of Symphyla and omnivores were smaller in soils under kauri. Differences in mesofauna community response variables between tree types were mainly modulated by the soil C:N ratio, which had positive effects under broadleaf and neutral to negative effects under kauri. Energy fluxes to detritivores and fungivores were greater under larger trees, regardless of tree type or P. agathidicida detection status. Our findings suggest that kauri support soil mesofauna food webs that are distinctly different from those found under broadleaf trees in the same habitat. A decreased presence of this foundation species may be linked to future impacts on soil mesofauna in this forest ecosystem with increasingly advanced stages of kauri dieback.

Soil is essential for the sustenance of life. Diverse soil organisms support several biological processes such as organic matter decomposition, mineralization, nutrient cycling, and controlling pests and diseases. Among multicellular soil organisms, nematodes are ubiquitous, functionally diverse, and abundant. Notably, agricultural practices have diverse impacts on plants, soils, and soil organisms. Tillage affects nematodes directly by altering pore size and disrupting the continuity of water films and indirectly by affecting the lower trophic groups such as bacteria and fungi. The primary goal of this study was to examine the effect of increasing levels of physical disturbance on nematode communities in an undisturbed forest ecosystem. The experiment included four treatments: control with no disturbance, surface litter removed with no litter and no vegetation, tilling the soil with a rototiller every 2 mon, and every 2 wk. Tillage significantly reduced the overall abundance and overall richness of nematode communities over time. Among nematode trophic groups, tillage significantly reduced the abundance and richness of bacterial feeders, predators, and omnivores over time. The abundance and richness of c-p 2, c-p 4, and c-p 5 class nematodes were significantly decreased by tillage. Unlike tillage, minimal disturbance such as removal of surface litter resulted in a significant decrease in the abundance of only three genera: Acrobeles, Aporcelaimellus, and Boleodorus. Nonmetric multidimensional scaling analysis revealed that nematodes of higher c-p classes such as Dorylaimida, Aporcelaimellus, Alaimus, Clarkus, and Tripyla were sensitive to physical disturbances. Bacterial feeders belonging to the c-p 2 class such as Tylocephalus, Acrobeles, Ceratoplectus, Plectus, and Pseudacrobeles were significantly reduced by tillage. Moreover, tillage significantly reduced the functional metabolic footprint of nematodes, which indicates decreased metabolic activity, reduced C inflow, and poorly structured soil food webs. Previous studies conducted in agricultural ecosystems determined that Clarkus, Filenchus, and Plectus were tolerant to tillage; however, they were found sensitive to tillage in our study. Overall, our study suggests that increasing levels of physical disturbance are detrimental to nematode community abundance and diversity that could affect soil ecosystem stability and sustainability.

Nematodes are an integral part of soil biodiversity and play a vital role in soil nutrient cycling. The Himalayan mountainous ecosystems are amongst the extreme environments in the world. Still little is known about the diversity and distribution patterns of soil nematodes along the elevation gradient in the region, thus limiting our ability in understanding and comparing the structural patterns of nematode communities across different regions. To address this knowledge gap, we aim to disentangle the elevational patterns of soil nematode community structure and trophic diversity by studying the abundance, composition, diversity and functional indices, and metabolic footprint of soil nematodes at four elevation classes (Elev1, Elev2, Elev3, and Elev4 each being 400 m) along an altitudinal gradient (1,000–2,600 m) in the Trikuta mountain range of Pir-Panjal to Shivalik Himalaya. Overall, a total of 55 genera were found in the study region. The diversity and richness of soil nematodes varied significantly among the elevation classes, and exhibit a decreasing trend with elevation. Also, the nematode community composition varied significantly among the elevation classes along the elevational gradient. The bacterivores were the dominant trophic group at each elevation class. Further, the soil properties played a key role in explaining the changes in the nematode community composition across the elevation classes. Moreover, the total nematode, bacterivore and herbivore abundances showed an increasing trend, while as that of fungivores and predators exhibit a negative trend with elevation. In addition, a declining pattern in the overall maturity and metabolic footprint with elevation was observed, thus depicting the lower sustenance of k-strategic nematodes and their relatively lower contribution to belowground carbon cycling at higher elevations. The finding of our study could enhance our understanding of the overall community structure and diversity patterns of soil nematode along the elevation gradient, and the response of soil nematodes to ongoing climate change in the rapidly warming Himalayas.

Background: Gradients in local environmental characteristics may favour the abundance of species with particular traits, while other species decline, or favour species with different traits at the same time, without an increase in average species abundances. Therefore, we asked: do variations in species and traits differ along gradients of deadwood variables? Do species abundance and trait occurrence change with species richness within or between functional groups? Thus, we analysed the beetle assemblages of five forest sites located in Italy, along the Apennines mountains. Methods: From 2012 to 2018 we sampled beetles and five deadwood types in 193 plots to characterise the deadwood gradient: standing dead trees, snags, dead downed trees, coarse woody debris, and stumps. We modelled beetle species relative abundances and trophic traits occurrences against the deadwood variables using joint species distribution models. Results: Out of 462 species, only 77 showed significant responses to at least one deadwood type, with a weak mean response across species. Trophic groups showed mostly negative responses to deadwood variables. Species abundance increased with species richness among sites only for phytophagous and saproxylophagous. Trait occurrence did not increase with species richness among sites, except for phytophagous and saproxylophagous. However, trait occurrence changed significantly with species richness of several trophic groups within some sites. We found that increases in species richness do not result in decreases in species abundance of a given trophic group, but rather null or positive relationships were found suggesting low interspecific competition. Conclusions: Our findings suggest that in Mediterranean mountain forests there is still room for increasing the level of naturalness, at least for what concerns deadwood management. On one side, our findings suggest that competition for deadwood substrates is still low, on the other side they indicate that increasing deadwood volume and types to improve overall beetle richness may increase also beetle abundances. [ABSTRACT FROM AUTHOR]

Fishes play significant ecological functions though many ways in coral reef, and feeding process is one of the most important. To understand responses of reef fish communities to external disturbances, we studied variations in trophic groups of fishes in the lagoon of Meiji Reef in the South China Sea based on fish specimens collected by hand-line and gillnet in 1998—2018, databases and literatures. Differences in species richness, abundance, weight and size of fish in different trophic groups among years were analysed, especially herbivorous and high-economy fish. The results indicated that the percentages of species number and weight of herbivores, piscivores and detritivores decreased significantly from 1998—1999/2016—2018. Herbivorous fishes saw the biggest decline. In the gillnet surveys, the percentages of species number and weight of herbivorous fishes in 1999 were 33.33% and 56.14%, respectively, while the percentages in 2016—2018 were all zero. The species number percentage of large-sized fishes (maximum total length ≥ 65 cm) in 1998—1999 was significantly larger than that in 2016—2018. Thirty-two fish species being found in the lagoon of Meiji Reef during 1998—1999 were not discovered during 2012—2018. Contingency table analysis showed that the disappearance of fish was not significantly related to the vulnerability or resilience of fish rather than economic value. The mean body weight of very high & high-value fish in 1998—1999 was significantly larger than that in 2016—2018. Simple linear regression showed that coral cover had the greater effect on the species number and weight of herbivorous fishes as compare to fishing power. Both fishing power and coral cover had significant effects on the mean body weight. To protect fish on Meiji Reef, we propose to strengthen the conservation initiatives (e.g., creating protected areas, prohibiting fishing, and reconstructing habitat).

Background: Gradients in local environmental characteristics may favour the abundance of species with particular traits, while other species decline, or favour species with different traits at the same time, without an increase in average species abundances. Therefore, we asked: do variations in species and traits differ along gradients of deadwood variables? Do species abundance and trait occurrence change with species richness within or between functional groups? Thus, we analysed the beetle assemblages of five forest sites located in Italy, along the Apennines mountains. Methods: From 2012 to 2018 we sampled beetles and five deadwood types in 193 plots to characterise the deadwood gradient: standing dead trees, snags, dead downed trees, coarse woody debris, and stumps. We modelled beetle species relative abundances and trophic traits occurrences against the deadwood variables using joint species distribution models. Results: Out of 462 species, only 77 showed significant responses to at least one deadwood type, with a weak mean response across species. Trophic groups showed mostly negative responses to deadwood variables. Species abundance increased with species richness among sites only for phytophagous and saproxylophagous. Trait occurrence did not increase with species richness among sites, except for phytophagous and saproxylophagous. However, trait occurrence changed significantly with species richness of several trophic groups within some sites. We found that increases in species richness do not result in decreases in species abundance of a given trophic group, but rather null or positive relationships were found suggesting low interspecific competition. Conclusions: Our findings suggest that in Mediterranean mountain forests there is still room for increasing the level of naturalness, at least for what concerns deadwood management. On one side, our findings suggest that competition for deadwood substrates is still low, on the other side they indicate that increasing deadwood volume and types to improve overall beetle richness may increase also beetle abundances.

Copyright of Düzce University Journal of Forestry / Düzce Üniversitesi Orman Fakültesi Ormancılık Dergisi is the property of Duzce University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La Reserva El Caduceo, ubicada en San Martín, Meta, es un área que ha experimentado notables modificaciones en la complejidad estructural de la vegetación de bosques y sabanas debido al efecto de diferentes actividades de cultivo y ganadería, las cuales pueden afectar la riqueza de las comunidades de aves que allí habitan. Este estudio corto muestra una evaluación de la composición y abundancia a nivel de familias y grupos tróficos de aves en esta reserva durante la época lluviosa de 2020. Se llevaron a cabo censos visuales con límite de tiempo en dos estaciones correspondientes a dos hábitats: bosque de galería y sabana con pequeños núcleos de bosque. Además, se estimaron algunos índices ecológicos para cada estación de muestreo. Se observó un total de 18 familias, de las cuales la familia Tyrannidae fue la más abundante en la sabana y la familia Psittacidae la más recurrente en el bosque de galería. La densidad de aves fue mayor en el bosque de galería (2,19 ind/m2), observando además que en esta estación las densidades de aves se encuentran equitativamente repartidas entre las familias registradas, en contraste con la estación de sabana. Por otro lado, el grupo trófico dominante en ambas estaciones fueron los “insectívoros”. Estos resultados preliminares podrían indicar una relación directa entre la complejidad estructural vegetativa, la recuperación del bosque de galería en esta zona y la composición de aves y grupos tróficos predominantes. No obstante, futuros estudios con mayor duración y monitoreos constantes son necesarios para confirmar esta observación inicial.

Research Highlight: Li, X., Liu, T., Li, H., Geisen, S., Hu, F., & Liu, M. (2022). Management effects on soil nematode abundance differ among functional groups and land‐use types at a global scale. Journal of Animal Ecology, https://doi.org/10.1111/1365‐2656.13744. Despite the well‐documented decline of aboveground species abundances as a result of land‐use intensification, there has been little attention on the effects of human activities on belowground species abundances. Li et al. analyse nematode data, the most abundant animal on the planet, from across the globe to determine whether their abundances vary between managed and unmanaged habitats. The authors show that, unlike aboveground biodiversity, nematode abundance is higher in managed than unmanaged primary and secondary habitats. Furthermore, responses to land management vary between trophic groups and they do not appear to follow the general hypothesis that higher trophic levels are more vulnerable to human activity than those further down the food chain, except in urban habitats. Finally, Li et al. show that the relationships between environmental predictors and species abundance were weakened (and sometimes reversed) in managed habitats. Together, their results reveal how land‐use management is impacting the trophic composition of soil nematode communities and their relationships with the environment, which has implications for ecosystem functioning. [ABSTRACT FROM AUTHOR]

Recent losses of seagrass beds have resulted in a decrease in seagrass-associated fishes, highlighting the need for the improved management of such habitats and resources. Analyses of feeding patterns of fish associated with seagrass habitats are useful for understanding their habitat dependence, which contributes to achieving their effective conservation. The gut contents of 61 fish species were examined to clarify the food habits of subtropical seagrass fishes in Nagura Bay, Ishigaki Island, southern Japan. A cluster analysis based on dietary overlaps showed that the seagrass fish assemblage comprised six trophic groups (small crustacean, large crustacean, detritus, plant, fish and zooplankton feeders). Small and large crustacean feeders were the most abundant, followed by detritus, plant and fish feeders. Zooplankton feeders were represented by only two species. Ontogenetic changes in food preference were recognized in four species, including Lutjanus fulviflamma , Ostorhinchus ishigakiensis , Gerres oyena and Siganus fuscescens. Small individuals of the four species generally fed on small crustaceans or detritus, subsequently switching to other larger prey items with growth (e.g. crabs, shrimps and seagrass fronds). The most important food items for the assemblage comprised harpacticoid copepods, shrimps, crabs and detritus, representing high cumulative gut volumes for all fishes. Some species showed diets remarkably different from those determined for fishes in other seagrass beds off a nearby neighbouring island, evidence of the food-use patterns of seagrass fishes varying on a small spatial scale. Such dietary flexibility may increase the adaptability of fishes to seagrass beds characterized by significant variations in available food resources. [ABSTRACT FROM AUTHOR]

Aims: Soil nematodes, as key bioindicators, play crucial roles in soil ecological process. Management of grasslands, such as meadow steppes in northeast China, is often done by mowing, which has an impact on soil nematode communities. However, few studies have explored effects of mowing frequency on the community structure and biomass of soil nematodes. Methods: Routine field and laboratory methods concerning plant community, soil properties, and soil nematodes were applied in this study. Soil nematode community structure was analyzed by using nonmetric multidimensional scaling (NMDS) and principal component analysis (PCA). The relationships between nematode genus and biotic and abiotic factors were analyzed by redundancy analysis (RDA). Results: High mowing frequency significantly reduced abundance, biomass, and functional or metabolic regimes of soil nematodes in this ecosystem, whereas moderate mowing frequency enhanced those indices and regimes. Conclusions: Our findings showed that changing patterns in nematode indices across the mowing frequency conformed with the intermediate disturbance theory. Variations in soil nematode community were related to changes in belowground biomass, aboveground litter, soil available nitrogen and acidity, and the effects of edaphic and vegetal traits appeared to be trophic or genus-specific. This study has potential benefits for grassland restoration in northeast China. [ABSTRACT FROM AUTHOR]

Analysis of soil nematode feeding groups and functional guilds were used as a valuable tool to detect heavy metal pollution. Effects of cadmium (Cd) at 5 mg/kg, mercury (Hg) at 20mg/kg, combined Cd and Hg at 5+20mg/kg on the nematode communities were studied after three months application. Nematodes were collected from soil in rhizosphere of Morning glories (Pharhiris nil) which were applied as heavy metal accumulators and were grown in the experimental pots. Both single and combined heavy metals had marked effects on the nematode abundance, life-history strategies and feeding type composition. Bacteriovores and c-p 2 group were found to be the most abundant trophic group and functional guild, respectively. Acrobeloides and Pratylenchus were the most two abundant genera, decreasing number of them was responsible for the significant difference between control and polluted treatments. Cd-5 and Cd-Hg 5+20 presented lower values of nematode diversity index (H’) and evenness index (J’) than Hg-20. The combination of Cd and Hg showed lower nematode trophic diversity (TD), in comparison with single Cd or Hg. Conversely, heavy metals addition exhibited no pronounced effect on Maturity index (MI), structural index (SI) and enrichment index (EI). Our results demonstrate that genera composition is a better indicator to short-term heavy metal effects than some common indicator indices and emphasize that deeper assemblage analyses are needed for a correct interpretation of short-term disturbance on soil nematodes.

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microplastic (MP, <5 mm) contamination in the ocean raises concern for zooplankton, as their prey and MPs fall within the same size range. This study aimed to evaluate the ingestion capacity of MPs among a diverse array of mesozooplankton taxonomic groups and species from the central Mexican Pacific, focusing on two functional traits: trophic group and feeding strategy. A total of 20 taxa belonging to eight taxonomic groups, 13 which were identified to species level, were exposed to microspheres (Ms) ranging in size from 38 to 53 μm, at a concentration of 100 Ms/mL. All experimental treatments were placed in 620 mL bottles and rotated on a plankton wheel for 2 h. The results demonstrate that the capacity to ingest MPs is closely related to the trophic group and the feeding strategy of each species, independent of taxonomic group. Omnivores and omnivore-herbivores which generate feeding currents were the most susceptible to MPs ingestion, while highly carnivorous species with active feeding strategies were the least prone. These findings highlight the importance of evaluating MP ingestion by zooplankton at the species level, due to the variability of feeding strategies within taxonomic groups, and the need for continued trait-based research at the species level. A more detailed understanding of zooplankton feeding behavior, especially in ecologically significant species, could enhance trait-based modeling at a biogeographic scale, predicting areas with the highest risk of MP ingestion by zooplankton communities and evaluating global impacts. • Zooplankton were exposed to microspheres (Ms) at a concentration of 100 Ms/mL. • Individuals were identified and classified by trophic group and feeding strategy. • Feeding current omnivores and omni-herbivores were most susceptible to Ms ingestion. • Active feeding (active ambush and cruise) carnivores were less prone to Ms ingestion. • The capacity to ingest MPs is closely related to trophic group and feeding strategy of each species. [ABSTRACT FROM AUTHOR]

Wildfires are among the basic ecological factors that change habitats and initiate the succession of new forest communities. Burned areas are ephemeral habitats presenting a broad range of ecological niches that many insect species may exploit. In 2016, we studied the carabid fauna in burned pine forests of the Mordovia State Nature Reserve (European Russia). Sixty carabid beetles in total were collected in an unburned (control) area and on sites damaged by crown fire and surface fire. Carabids were more numerous and diverse in the burned areas, compared to the unburned forest, while the catch index was significantly higher in unburned area. This was due to the extremely high dynamic density of Carabus arcensis on the control site, while it was ten times lower in the burned area. The number of carabid species tended to increase in the sequence unburned forest – forest impacted by surface fire – forest impacted by crown fire. Expectedly, species compositions were more similar between fire-damaged areas, while there was a higher difference between the unburned site and area damaged by crown fire. Concerning trophic group classification, all carabid beetles were distinguished in two groups, zoophagous species and myxophytophagous species. In both groups, the species number increases in the sequence from unburned areas to the forest impacted by crown fire. Finally, the dynamic density of some carabids (e.g. Poecilus lepidus, P. versicolor, Harpalus tardus, H. rufipes, H. rubripes, Cicindela sylvatica) largely increased after fire impact, while it decreased for the most other species. Our results suggest that burning of the forest stand may support some carabid species, i.e. larger forest fire increases species richness of beetle fauna. The highest dynamic density of the carabids is maintained by a few beetle species (Carabus arcensis, C. hortensis, Pterostichus oblongopunctatus).

Copyright of Revista Mutis is the property of Revista Mutis and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Human activity has extensively transformed the land surface by agricultural intensification and urbanization. In soil, nematodes are the most abundant invertebrates. The effect of human interventions was assessed on overall richness, overall abundance, richness and abundance of nematodes of each trophic group and colonizer-persister (c-p) guild by comparing urban, agriculture and disturbed grassland (DGL) with natural grassland (NGL) and forest ecosystems. Meta-analyses were conducted to generate quantitative summaries from 111 published articles that met the inclusion criteria, 91 expressed data in grams and 20 expressed data in cm3. Results from data expressed per 100 g of soil indicated that overall richness was higher in forest than in NGL, DGL, urban, and agriculture ecosystems. The richness of all c-p guilds and of all trophic groups except herbivores was highest in forest ecosystems. In contrast, overall abundance was highest in DGL, agriculture and forest ecosystems. The abundance of c-p 1, c-p 2 and c-p 3 guilds and bacterivores, fungivores and herbivores was highest in disturbed ecosystems, while the abundance of c-p 4 and c-p 5 guilds and predators and omnivores was highest in relatively undisturbed ecosystems. Results from data expressed as nematodes per 100 cm3 of soil indicated that abundance followed a similar pattern, but richness often differed between the two methodologies. These meta-analyses strengthen the concept that human interventions adversely impact both richness and abundance using nematodes as soil health bioindicators.

To study the effect of fertilization on soil nematode communities in a paddy-upland rotation system, an ongoing thirty-three years long-term fertilizer experiment is conducted which includes seven treatments; an unfertilized treatment (control), nitrogen (N), phosphorus (P), potassium (K) fertilizer treatments (N, NP, NPK) and organic manure (M) combined with chemical fertilizer treatments (MN, MNP, and MNPK). The soil nematode community structure and crop yields were determined in 2012 and 2013. Overall total nematode abundance was increased by an incremental nutrient input both in the rice and wheat fields. Total number of nematode was 1.25 - 2.37 times greater in the rice field and was 1.08 - 2.97 times greater in wheat field in the fertilization treatments than in the unfertilized treatment. Soil free-living nematode abundances was significantly (P < 0.001) increased in organic manure combined with chemical fertilizer treatments in rice field. Fungi-feeders and plant-feeding nematodes abundances were not significantly different among treatments in rice and wheat fields. Omnivorous and predatory nematodes were the most dominant groups in the present study. Omnivores, predators and Prodorylaimus abundances were significantly (P < 0.05) higher in organic manure combined with NPK fertilizer treatments than in chemical fertilizer alone and unfertilized treatments both in rice and wheat fields. Stepwise regressions revealed that soil free-living nematodes were significant predictors of rice grain yields (R2 = 0.56, P < 0.001) and omnivorous and predatory nematodes were significant predictors of the wheat grain yield (R2 = 0.89, P < 0.001). Therefore, long-term application of organic manure combined with chemical fertilizer could increase nematode abundances and crop yields. Organic manure combined with chemical fertilizer application was recommended in agricultural ecosystem.

Selective logging has been widely employed as a management practice in tropical forests due to its reduced impact on biodiversity. However, by altering microclimatic conditions, logging could affect soil fauna responsible for nutrient cycling and the long-term dynamic of the forest. We investigated how selective logging affected termite species richness, composition, and the distribution of species in trophic groups, as well as the natural response of termites to gradients of soil conditions. Termites and edaphic variables were sampled in 32 permanent plots in southern Amazonia. Plots were subject to selective logging for 10–31 years before termite sampling. Time post-management was associated with changes in termite species composition, and wood-feeding termites were more abundant in recently logged areas. Nevertheless, most of the variation in termite species richness and composition can be attributed to the natural variation in soil clay content. Moreover, soil-dweller species, a vulnerable group strongly linked to soil decomposition, were present in all plots. These results suggest that the impact of selective logging on termite communities might be milder compared with other types of disturbance. It is likely that the decomposition process performed by termites, and consequently long-term ecosystem functioning, is preserved under selective logging. [ABSTRACT FROM AUTHOR]

Climate change‐amplified temperature anomalies pose an imminent threat to coral reef ecosystems. While much focus has been placed on the effects of heat stress on scleractinian corals—including bleaching, mortality, and loss of reef structural complexity—and many studies have documented changes to reef fish communities arising indirectly from shifts in benthic composition, the direct impacts of heat stress on reef fish are much less well understood. Here, we quantify the direct and indirect effects of heat stress on reef fishes, using underwater visual censuses of coral reef fish communities conducted before, during, and after the 2015–2016 El Niño‐induced global coral bleaching event. Surveys took place at the epicenter of this event, at 16 sites on Kiritimati (Republic of Kiribati; central equatorial Pacific) spanning across a gradient of local human disturbance. We expected that heat stress would have both direct and indirect negative effects on the reef fish community, with direct effects resulting from physiological stress during the event and indirect effects manifesting afterward as a consequence of coral mortality, and that the ability of fish communities to recover following the heat stress would depend on levels of local human disturbance. We found that total reef fish biomass and abundance declined by >50% during heat stress, likely as a result of vertical migration of fish to cooler waters. One year after the cessation of heat stress, however, total biomass, abundance, and species richness had recovered to, or even exceeded, pre‐heat stress levels. However, the biomass of corallivores declined by over 70% following severe coral loss, and reefs exposed to higher levels of local human disturbance showed impaired recovery following the heat stress. These findings enhance understanding of the projected impacts of climate change‐associated marine heatwaves on reef fishes, and highlight the interacting effects of local and global stressors on this vital component of coral reef ecosystems. [ABSTRACT FROM AUTHOR]

1. Testing the extent to which traits act alone or in combination with other traits to influence responses to fire informs the trade‐off between increased generalisation using single traits and increased predictive power using interactions. This study investigated the following question: do four traits (body size, trophic group, dispersal ability, and stratum of the ecosystem), alone or in combination, best explain changes in beetle occurrence with time since fire? 2. The data from 4 years and 15 independent fires in southern Australia were analysed using generalised linear mixed models. The study also assessed whether detectability depends on time since fire using multi‐year detection models, because detectability has the potential to confound occurrence patterns. 3. The best model included the three‐way combination of size, flight, and trophic level interacting with time since fire and with year. The relationship between detectability and time since fire was similar to the occurrence relationship in six of the 10 trait–combination groups, with flightless species generally showing reduced detection probability as time since fire increased. Detectability did not confound occurrence responses for four trait groups, with three increasing with time since fire and one decreasing. 4. Generalisation using main effects of traits risks oversimplifying animal responses to fire, because combinations of traits influence the direction and magnitude of the response. Also, taking detectability into account is critical to correctly interpretating occupancy data. Three‐way trait combinations that differ by just one trait, particularly dispersal ability, can result in either negligible effects of disturbance on detectability or strong effects that influence observed occurrence. [ABSTRACT FROM AUTHOR]

Background Transgenic Bt rice has not been approved for commercial cultivation because of the fierce public debate on food safety, biosafety regulation and ecological risk. Meanwhile, the concentration of CO2 and temperature in the atmosphere, as important environmental factors affecting the persistence of exogenous Bt protein, have increased. Elevated CO2, increased temperature, the planting of transgenic Bt rice and their interactions may further influence the structure and complexity of soil food web. However, the effects of transgenic Bt rice planting on soil organism remain largely unexplored before its commercial production especially under global climate change. Methods Here, we assessed the influences of transgenic Bt rice (cv. HH with fused Cry1Ab/Cry1Ac in contrast to its parental line of non-Bt rice cv. MH63) on soil nematode communities under the conditions of elevated CO2 concentration and increased temperature for 2 years of 2016 and 2017 in open-top chambers located in Ningjin County, Shandong Province of China. Results Elevated CO2 concentration remarkably increased the abundance of fungivores and significantly decreased their nematode channel ratio (NCR) and enrichment index (EI) irrespective of rice variety (transgenic Bt rice or non-Bt rice) or temperature (normal temperature or increased temperature). Additionally, rice variety and temperature did not significantly change soil nematode composition, abundance and ecological indices (including total maturity index (∑MI), Shannon diversity (H′), structure index (SI), NCR and EI). However, apparent seasonal changes were observed in theses aforementioned variables. Discussion These results suggested that atmospheric CO2 concentration but not temperature or rice variety has great impacts on soil nematode community, especially fungivores.

Background. Transgenic Bt rice has not been approved for commercial cultivation because of the fierce public debate on food safety, biosafety regulation and ecological risk. Meanwhile, the concentration of CO2 and temperature in the atmosphere, as important environmental factors affecting the persistence of exogenous Bt protein, have increased. Elevated CO2, increased temperature, the planting of transgenic Bt rice and their interactions may further influence the structure and complexity of soil food web. However, the effects of transgenic Bt rice planting on soil organism remain largely unexplored before its commercial production especially under global climate change. Methods. Here, we assessed the influences of transgenic Bt rice (cv. HH with fused Cry1Ab/Cry1Ac in contrast to its parental line of non-Bt rice cv. MH63) on soil nematode communities under the conditions of elevated CO2 concentration and increased temperature for 2 years of 2016 and 2017 in open-top chambers located in Ningjin County, Shandong Province of China. Results. ElevatedCO2 concentration remarkably increased the abundance of fungivores and significantly decreased their nematode channel ratio (NCR) and enrichment index (EI ) irrespective of rice variety (transgenic Bt rice or non-Bt rice) or temperature (normal temperature or increased temperature). Additionally, rice variety and temperature did not significantly change soil nematode composition, abundance and ecological indices (including total maturity index (ΣP MI), Shannon diversity (H'), structure index (SI), NCR and EI). However, apparent seasonal changes were observed in theses aforementioned variables. Discussion. These results suggested that atmospheric CO2 concentration but not temperature or rice variety has great impacts on soil nematode community, especially fungivores. [ABSTRACT FROM AUTHOR]

The interspecific relationships between abundance and site occupancy have been widely studied in plants and animals, but principally in terrestrial systems. With few exceptions, a positive abundance–occupancy relationship has been reported. Few publications have included freshwater fish, possibly suggesting a general lack of abundance–occupancy patterns for this taxonomic group.We examined the relationship between abundance and the extent of site occupancy by 145 species of freshwater fish, including nine non‐indigenous species, sampled over 85 sites spread across the Duck River Basin, Tennessee, U.S.A.A distinct (r2 = 0.79) positive abundance–occupancy curve was observed, with curves differing relative to feeding and size guilds, but not relative to environmental tolerance, conservation status (i.e. listed/non‐listed), or origin (i.e. indigenous/non‐indigenous).The patterns observed are consistent with those reported in many studies of terrestrial taxa.The existence of positive abundance–occupancy relationships in stream fish has at least two major implications for fish conservation. First, species that decrease in occupancy due to anthropogenic disturbances are likely to decrease in abundance, facing inflated prospects for local extinction. Second, occupancy alone may be used to index community status and the need for, or success of, conservation activities. [ABSTRACT FROM AUTHOR]

Tea is an economically important crop, consumed by billions of people. Despite the increasing market for pesticide-free products, the use of pesticide in tea is still high. In order to investigate whether intercropping promotes biological control organisms, Chamaecrista rotundifolia (Pers.) Greene, Indigofera hendecaphylla Jacq. Trifolium repens L. and Vigna sinensis (L.) were separately intercropped with free weeding as control in a tea plantation at Yangli, China. Arthropods were collected by taking sweep-net samples, and treatment effects on assemblages were investigated. The combined species richness of all arthropods and that of parasitoids was significantly increased in intercropped treatments while the species richness of herbivores and predators was only greater in C. rotundifolia and I. hendecaphylla intercropped treatments. Compared with control, the combined abundance of all arthropods, and that of herbivores was lower, while the abundance of parasitoids and its taxa was greater in all intercropped treatments. The abundance of predators and its taxa was greater only in tea plantations intercropped with C. rotundifolia or I. hendecaphylla. Of the herbivores, the abundance of Empoasca onukii Matsuda, Sternorrhyncha, Aleyrodidae, and Pentatomidae was greater in the areas intercropped with C. rotundifolia in comparison with the control, but the abundance of Thysanoptera and Geometridae caterpillars was lower. The recorded increase in the abundance of beneficial arthropods may explain the lower abundance of Thysanoptera or Geometridae caterpillars detected in the intercropped tea plantations. Our results indicate that intercropping has the potential to enhance arthropod biodiversity, and to provide an option for sustainable pest control in tea plantations. [ABSTRACT FROM AUTHOR]

Soil nematodes are ubiquitous in terrestrial ecosystems. Nematodes are one of the most abundant groups of soil invertebrates, and they influence ecosystem processes and functions. Plant litter is a fundamental factor in controlling the structure of belowground communities. The addition of nitrogen (N) can restructure soil nematode communities by affecting the quantity and quality of litter input into soil. However, little is known about how N and litter interact to affect nematode communities. We examined the response of soil nematodes to the addition of N and litter manipulation (i.e. initial litter, removal, addition) in a 6‐year field experiment in grassland, and quantified the effects of additions of N and litter on nematode abundance, diversity and community structure through the plant community and nutrients in soil. There were interactive effects between additions of N and litter on nematode numbers and trophic group abundance, the Shannon–Wiener index (H′) and the maturity index. The addition of litter without that of N increased the total and trophic group abundance, whereas the addition of N and litter decreased nematode H′ and the maturity index. Structural equation modelling (SEM) revealed that the addition of N decreased herbivore abundance through increasing plant N concentration, and directly decreased fungivore abundance and indirectly decreased bacterivore and omnivore predator abundance through fungivores. The positive effects of litter addition on nematodes without the addition of N and its negative effects on treatments with the addition of N suggested that without added N, increased litter accumulation could benefit the soil nematode community. However, under scenarios of N deposition, grassland management that reduced litter accumulation, such as grazing and mowing, could also benefit soil nematode communities. Highlights: There were interactive effects between additions of N and litter on nematode communityN addition decreased nematode abundance and diversity in litter addition treatmentsWithout N addition, litter addition increased nematode abundance and diversityNematodes were affected mainly through decreased fungivore abundance [ABSTRACT FROM AUTHOR]

Investigations on the free-living, pelagic copepod community of the Algerian coasts were performed at the Habibas Islands and in Bou Ismail Bay (Sidi Fredj coast) between 0 and 100 meter depth during various seasons of the year 2012-2013. Seventy-seven taxa at species level have been identified, belonging to 47 genera and 24 families. The distribution of the copepod community revealed seasonal variability; high abundance and species richness (greater than 20 species) characterized winter and spring, while the summer period was characterized by low abundance and species richness. The spatial distribution showed high abundance and species richness on the Sidi Fredj coast (the respective mean abundances along the Sidi Fredj coast and at the Habibas Islands were 253.71 ind.m−3 and 109.77 ind.m−3, respectively). Analysis of the samples showed the presence of seven abundant and frequent species: Centropages typicus, Eucalanus elongatus, Pleuromamma abdominalis, Paracalanus parvus, Paracalanus nanus, Calanus helgolandicus, and Temora stylifera. Multivariate analysis (ascending hierarchical classification and non-metric multidimensional scaling) enabled us to group the stations according to the composition in the copepod species, and the influence of seasonal changes was well observed. A dominance of herbivorous behaviour, followed by an omnivorous feeding strategy, was observed in the two studied areas. A dominance of epipelagic and epi-mesopelagic species was observed during all seasons, reflecting a neritic character of both study areas. [ABSTRACT FROM AUTHOR]

Soil amendment may enhance soil quality as well as reduce plant-parasitic nematode. Despite the many applications already undertaken using castor meal, its efficiency in controlling root-knot nematodes (RKN, Meloidogyne incognita) when applied to melon (Cucumis melo) is still not clear. Three different amounts of castor meal (Ricinus communis) applied were evaluated in microplots planted with melon either with or without RKN. The impact of castor meal on soil free-living nematode communities was also determined. Total nematode genera richness was estimated as 37 for the entire set of microplots sampled across both sampling dates. Rarefaction analysis resulted in 12 collector's curves out of the total of 30 that reached the horizontal asymptote. Univariate ANOVA with two factors yielded differences (p < 0.05) only with regard to the time factor. Simpson, Shannon, Evenness and Equitability indices showed a trend toward moderate increases by the end of the experiment, while the other indices were higher for tomato in pre-transplant sampling compared to harvest. Nematode community and diversity changed during the course of the experiment, although there was substantial confounding heterogeneity within and between the factorial combinations from the beginning. Root knot population was not reduced by the castor meal but increased throughout the period, regardless of treatment. RKN reduced melon yield, number and weight of melon.

A substantial knowledge gap exists on how compost source and rate of application affect nematode community-based soil food web structure, soil health, soil physiochemistry, and crop yield and quality in short- and full-season crops. We tested effects of plant (PC)- and animal (AC)-based compost at 1, 1.5 and 2× the standard nitrogen (N) rate on processing carrot 'Cupar' and fresh market 'Sugarsnax 54' (short-season crop) over 2-3 growing seasons. Low abundance of nematodes and domination of herbivores and bacterivores indicate that the field is biologically stressed. While outcomes of most measured parameters varied by compost source and/or rate, an increase in soil food web structure with time was most consistent. A combination of the variable outcomes and correlation patterns suggest that a multifactor analysis may best quantify compost-driven changes in soil ecosystems as opposed to looking for changes in a single parameter. [ABSTRACT FROM AUTHOR]

Copyright of Ecological Engineering / Inżynieria Ekologiczna is the property of Polish Society of Ecological Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soil biota are responsible for essential ecosystem services such as carbon storage, nutrient cycling and water retention. However, assessment of the condition of soil biota is hampered by an overwhelming level of diversity. With representatives in all trophic levels of the food web, nematode communities can be used as bioindicators. Accurate assessment of nematode assemblages requires insight into the distribution of specimens with distinct food preferences. With the availability of taxon-specific quantitative PCR assays, distribution patterns of multiple nematode groups can be investigated simultaneously. Here, microscale patchiness of 45 nematode taxa was studied on 12 sampling sites (each with four adjacent microplots) located on arable fields or semi-natural grasslands ('system'), and on marine, river clay or sandy soils ('soil type'). From each microplot, five composite samples were collected. Contrary to our expectations, an increase in the number of cores per composite sample did not result in more accurate measurements, and apparently the levels of microscale patchiness of the taxa are low compared to what has been reported for oligophagous plant-parasites. System and soil type did not affect microscale distribution. To investigate the level of patchiness in more detail, detection probability ( DP) and variability of abundances were calculated. Common and widespread bacterivorous and fungivorous taxa had DP ≥ 90%, confirming low level of microscale patchiness. With DPs of 40%-70%, predators and most omnivores showed degrees of local clustering. An overview of mean variabilities of abundances is presented that offers insight into how feeding preferences impact the microscale distribution both between and within trophic groups. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)