Guild Composition Research Articles

Canopy plant composition and structure of Cape subtropical dune thicket are predicted by the levels of fire exposure.

The subtropical dune thicket (hereafter "dune thicket") of the Cape Floristic Region experiences a wide range of fire exposure throughout the landscape, unlike other dry rainforest formations that rarely experience fire. We sought to determine how fire exposure influences species composition and the architectural composition of dune thicket. We used multivariate analysis and diversity indices based on cover abundance of species to describe the species composition, architectural guild composition and structure of dune thicket sites subject to different levels of fire exposure, namely low (fire return interval of >100 years), moderate (fire return interval of 50-100 years), and high (fire return interval of 10-50 years). The diversity, cover abundance and architectural guild cover abundance of dune thicket canopy species were strongly influenced by the level of fire exposure such that each level was associated with a well-circumscribed vegetation unit. Dune thickets subject to low fire exposure comprises a floristically distinct, low forest characterized by shrubs with one-to-few upright stems (ca. 4-8 m tall) and a relatively small canopy spread (vertical growers). Of the 25 species in this unit, 40% were restricted to it. Dune thickets subject to moderate fire exposure had the highest abundance of lateral spreaders, which are multi-stemmed (ca. 3-6 m tall) species with a large canopy spread and lower stature than vertical growers. None of the 17 species found in this unit was restricted to it. Dune thickets subject to high fire exposure had the highest abundance of hedge-forming shrubs, these being low shrubs (ca. 0.6-1.4 m tall), with numerous shoots arising from an extensive system of below-ground stems. Of the 20 species in this unit, 40% were restricted to it. Multivariate analysis identified three floristic units corresponding to the three fire exposure regimes. Compositional structure, in terms of species and architectural guilds, was most distinctive for dune thickets subject to high and low fire exposure, while the dune thicket subject to moderate fire exposure showed greatest compositional overlap with the other units. Fire exposure profoundly influenced the composition and structure of dune thicket canopy species in the Cape Floristic Region. In the prolonged absence of fire, the thicket is invaded by vertical-growing species that overtop and outcompete the multi-stemmed, laterally-spreading shrubs that dominate this community. Regular exposure to fire selects for traits that enable thicket species to rapidly compete for canopy cover post-fire via the prolific production of resprouts from basal buds below- and above-ground. The trade-off is that plant height is constrained, as proportionately more resources are allocated to below-ground biomass.

Effect of enviromental factors at multiple landscape scales on bird community in riparian ecosystem at Mun-Chi River confluence, Thailand

Abstract. Chaleekarn W, Duengkae P, Pongcharoen C, Sutummawong N, Nakmuenwai P, Siripin S, Chirachitmichi C, Kummoo W, Paansri P, Suksavate W. 2022. Effect of environmental factors at multiple landscape scales on bird community in riparian ecosystem at Mun-Chi River confluence, Thailand. Biodiversitas 23: 5194-5204. Wetland and riparian ecosystem is an important migratory stopover for land and water birds in the East Asian - Australasian Flyway. Understanding relationship patterns between bird communities and environmental factors at multi-spatial scales within a landscape context could contribute to the conservation and management of bird biodiversity in wetland ecosystems. The landscape metrics index is critical in revealing the relationship between the composition of bird communities and habitats at both local and landscape scales. This study aims to determine the effect of the environmental factors at different designated spatial scales on the composition of local bird communities in terms of species and feeding guilds. Our study conducted a bird survey using 227-point transects along 40 tracks across different land cover types surrounding the Mun-Chi River confluence. Canonical correspondence analysis (CCA) was used to quantify the association between bird communities, represented by species and feeding guilds, and environmental factors with the integration of multilevel habitat metrics. From the results, the CCA showed patterns of the community-environmental association at multiple scales of patch, class, and landscape characteristics with the proportional explanation of 54% and 61.82% for the composition of species and feeding guilds, respectively. The results indicated the premise that the majority of bird species respond to the habitat at the local scale. Large forest patches can maintain migratory and resident bird species. Moreover, most avian groups were arranged primarily in a large forest core area, forest area, and Shrubland PA. The results confirmed existing information on feeding guilds. The prediction map of the principal component of avian species composition was created from the association with the drivers of land use, including crops, perennial farmland, and water body on the edge of forests. Therefore, wetland management must be done at both local and landscape scales to preserve suitable avian habitats.

Fossilized diatoms as indirect indicators of the origin of carbon stored in intertidal flats

Coastal systems store enormous carbon quantities in their sediment, which originates from various autochthonous and allochthonous sources. Carbon fluxes in coastal ecosystems have a strong effect on the recipient food-webs and carbon emission offsets. Yet, the relative importance of autochthonous vs. allochthonous C inputs to coastal carbon budget is still challenging to identify. Here, we combine diatoms preserved in the sediment with geochemical analyses to identify the sources of carbon stored in Africa’s largest intertidal seagrass beds at Banc d’Arguin, Mauritania. The area lies between an active ocean upwelling and the ‘Sahara-dust hotspot’ systems. The extensive seagrass beds of the area are thus expected to receive C from these neighboring systems in addition to producing C in-situ. Three sediment cores (50 cm) were collected at three intertidal sites with different hydrodynamic regimes, and analyzed for diatom composition, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), and carbon isotopic signatures (δ13C). Diatom taxa are grouped into three guilds: (1) benthic (epiphyte, epipelon, and epipsammon), (2) planktonic, and (3) freshwater. Benthic diatoms are considered to be autochthonous, while typical oceanic and freshwater diatoms are considered to be allochthonous. Benthic diatoms are the most diverse and abundant group, while allochthonous freshwater (i.e., dust imported) and typical upwelling (i.e., tidal imported) taxa ranked last in both abundance and species’ richness. Structure equation modelling shows that variation in the stored carbon is best explained by the total abundance of diatoms and guild composition. We conclude that the C stored in the intertidal seagrass beds of Banc d’Arguin is predominantly autochthonous. Our method provides an effective way to identify historical carbon sources in coastal systems.

Climate-driven animal mass mortality events: is there a role for scavengers?

SummaryAnimal mass mortality events (MMEs) will increase with weather and climate extremes. MMEs can add significant stress to ecosystems through extraordinary nutrient pulses or contribute to potential disease transmission risks. Given their efficient removal of carrion biomass from landscapes, we argue here for the potential of scavenger guilds to be a key nature-based solution to mitigating MME effects. However, we caution that scavenger guilds alone will not be a silver bullet. It is critical for further research to identify how the composition of scavenger guilds and the magnitude of MMEs will determine when scavengers will buffer the impacts of such events on ecosystems and when intervention might be required. Some MMEs are too large for scavengers to remove efficiently, and there is a risk of MMEs subsidizing pest species, altering nutrient cycling or leading to disease spread. Prioritizing native scavenger taxa in conservation management policies may help to boost ecosystem resilience through preserving their key ecological services. This should be part of a multi-pronged approach to MME mitigation that combines scavenger conservation with practices such as carcass dispersal or removal when exceeding a threshold quantity. Policymakers are urged to identify such thresholds and to recognize both the insects and the vertebrate scavengers that could act as allies for mitigating the emerging problem of climate-driven MMEs.

View from the Top: Insights into the Diversity and Community Assembly of Ectomycorrhizal and Saprotrophic Fungi along an Altitudinal Gradient in Chinese Boreal Larix gmelinii-Dominated Forests.

The altitudinal patterns of soil fungi have attracted considerable attention; however, few studies have investigated the diversity and community assembly of fungal functional guilds along an altitudinal gradient. Here, we explored ectomycorrhizal (EcM) and saprotrophic (SAP) fungal diversity and community assembly along a 470 m vertical gradient (ranging from 830 to 1300 m) on Oakley Mountain, sampling bulk soils in the 0–10 cm and 10–20 cm soil layers of Larix gmelinii-dominated forests. Illumina MiSeq sequencing of the ITS genes was employed to explore the fungal community composition and diversity. The relative abundance of EcM and SAP fungi showed a divergent pattern along an altitudinal gradient, while we observed a consistent altitudinal tendency for EcM and SAP fungal diversity and community assembly. The diversity of both fungal guilds increased with increasing altitude. Altitude and soil moisture were the key factors affecting the community composition of both fungal guilds. In addition, the plant community composition significantly affected the EcM fungal community composition, whereas the dissolved organic nitrogen and ammonium nitrogen contents were the driving factors of SAP fungal community. Despite the effects of vegetation and soil factors, EcM and SAP fungal communities were mainly governed by stochastic processes (especially drift) at different altitudes and soil depths. These results shed new light on the ecology of different fungal functional guilds along an altitudinal gradient, which will provide a deeper understanding of the biogeography of soil fungi.

Invasive Species Appearance and Climate Change Correspond with Dramatic Regime Shift in Thermal Guild Composition of Lake Huron Beach Fish Assemblages

Lake Huron has undergone dramatic and well-documented lake-wide food web changes as a result of non-native species introductions. Coastal beaches, which serve as nursery habitats for native and introduced species, are, however, relatively poorly studied. Our objective was to assess fish assemblages of beach habitats in western Lake Huron and compare species composition pre- (1993) and post-invasion (2012) of dreissenid mussels and round goby (Neogobius melanostomus). Nearshore beach fish assemblages were sampled by nighttime beach seining during spring and summer in 1993 and 2012 in the western basin of Lake Huron along the Michigan shoreline. Catch rates were considerably higher, but there were fewer species present in 2012 than in 1993. The composition of species changed dramatically from a cold- and cool-water species assemblage in 1993 (dominated by alewife (Alosa pseudoharengus), spottail shiner (Notropis hudsonius), and lake whitefish (Coregonus clupeaformis), as well as Chinook salmon (Oncorhynchus tshawytscha) and rainbow smelt (Osmerus mordax)) to a cool- and warm-water species assemblage in 2012 (dominated by cyprinids, round goby (Nogobius melanstomus), and yellow perch (Perca flavescens)). The observed rise in catch rate and shift in species composition appears related to the introduction of invasive species as well as an on-going warming pattern in nearshore waters.

Impact of Transgenic Cry1Ab/2Aj Maize on Abundance of Non-Target Arthropods in the Field.

Transgenic Bacillus thuringiensis (Bt) maize has broad prospects for application in China. Before commercialization, it is necessary to assess possible ecological impacts, including impacts on non-target arthropods (NTAs) in the field. In the present study, transgenic Bt maize expressing cry1Ab/2Aj and its corresponding non-transformed near isoline were planted under the same environmental and agricultural conditions, and arthropods in the field were collected during the three main growth stages of maize. In a one year trial, the results showed the composition of NTA communities in the transgenic and control maize fields were similar. There were no significant differences for community-level parameters of species richness (S), Shannon–Wiener diversity index (H′), evenness index (J) and Simpson’s dominant concentration (C) between the two types of maize fields. Likewise, a Bray–Curtis dissimilarity and distance analysis showed that Cry1Ab/2Aj toxin exposure did not increase community dissimilarities between Bt and non-Bt maize plots and that the structure of the NTAs community was similar on the two maize varieties. Furthermore, planting of the transgenic cry1Ab/2Aj maize did not affect the density or composition of non-target decomposers, herbivores, predators, parasitoids and pollinator guilds. In summary, our results showed that planting of Bt maize producing Cry1Ab/Cry2Aj proteins do not adversely affect population dynamics and diversity of NTAs.

Diversity and Functional Relevance of Canopy Arthropods in Central Europe

Although much is known about the ecology and functional importance of canopy arthropods in temperate forests, few studies have tried to assess the overall diversity and investigate the composition and dynamics of tree-specific communities. This has impeded a deeper understanding of the functioning of forests, and of how to maintain system services. Here, we present the first comprehensive data of whole arthropod communities, collected by insecticidal knockdown (fogging) from 1159 trees in 18 study areas in Central Europe during the last 25 years. The data includes 3,253,591 arthropods from 32 taxa (order, suborder, family) collected on 24 tree species from 18 genera. Fogging collects free-living, ectophytic arthropods in approximately the same number as they occur in the trees. To our knowledge, these are the most comprehensive data available today on the taxonomic composition of arboreal fauna. Assigning all arthropods to their feeding guild provided a proxy of their functional importance. The data showed that the canopy communities were regularly structured, with a clear dominance hierarchy comprised of eight ‘major taxa’ that represented 87% of all arthropods. Despite significant differences in the proportions of taxa on deciduous and coniferous trees, the composition of the guilds was very similar. The individual tree genera, on the other hand, showed significant differences in guild composition, especially when different study areas and years were compared, whereas tree-specific traits, such as tree height, girth in breast height or leaf cover, explained little of the overall variance. On the ordinal level, guild composition also differed significantly between managed and primary forests, with a simultaneous low within-group variability, indicating that management is a key factor determining the distribution of biodiversity and guild composition.

Compartment and Plant Identity Shape Tree Mycobiome in a Subtropical Forest.

ABSTRACTDeciphering the relationships between microbes and their host plants is critical for a better understanding of microbial diversity maintenance and community stability. Here, we investigated fungal diversity and community assembly in the phyllosphere and rhizosphere of 13 tree species in a subtropical common-garden experiment. The results showed that fungal community structures significantly differed across compartments (leaf, root, and soil) and different tree species. Higher α-diversity was observed in the phyllosphere than in the roots and rhizospheric soil. Fungal community composition (β-diversity) was significantly affected by both compartment and species identity. The fungal community compositions were significantly correlated with soil pH in the roots and the soils as well as with soil nitrate and leaf total phosphorus in the leaves. We found that fungal community assemblies were mainly driven by deterministic processes, regardless of compartments. Moreover, host preference analyses indicated that stronger plant/fungus preferences occurred in leaves than in roots and soils. Our results highlight the differences in tree mycobiome between aboveground and belowground compartments and have important implications for the promotion of biodiversity conservation and management sustainability for the subtropical forest.IMPORTANCE Subtropical mountain forests are widely distributed in Southern China and are characterized by high biodiversity. The interactions between plants and fungi play pivotal roles in biodiversity maintenance and community stability. Nevertheless, knowledge of fungal diversity and of the community assembly patterns of woody plants is scarce. Here, we investigated fungal diversity and community assembly in the phyllosphere and rhizosphere of 13 tree species in a common-garden experiment. We found that both compartment and plant identity influenced fungal diversity, community, and guild compositions, while deterministic processes mainly governed the fungal community assembly, especially in the rhizospheric fungal communities. Our results demonstrate that tree leaves represent stronger host/fungi preferences than do roots and soils. Together, our findings enhance the understanding of the roles of compartment and plant identity in structuring fungal communities as well as promote fungal diversity maintenance in subtropical mountain forest ecosystems.

Influence of urbanization characteristics on ant (Hymenoptera: Formicidae) and spider (Arachnida: Araneae) diversity

Demographic characteristics and length of land use occupation time are important factors in the evaluation of the influence of urbanization on biodiversity. Thus, the aim of this study was to evaluate how population density and human occupation history influence taxonomic and guild spider (Arachnida: Araneae) and ant (Hymenoptera: Formicidae) diversities in four distinct Administrative Regions (ARs) of the municipality of Salvador (Bahia, Brazil). The ants and spiders in the ARs were collected in different types of green areas: forest fragments, vacant lots, and gardens/backyards, using three capture techniques (Winkler trap, entomological umbrella, and manual collection). We tested for eventual differences in myrmecofauna and araneofauna richness and composition, in addition to guilds (FGs) according to population density level (high vs. low) and urbanization time (old vs. recent). A total of 148 ant species were collected and classified into 15 guilds. Whereas a total of 97 spider species were captured and classified into 10 guilds. Spider richness varied significantly between the ARs, instead of to ant richness. There were also significant differences between ARs for the taxonomic composition of spiders, but not for ants. Those of the guild compositions of ants and spiders were not significant. Finally, our results indicate the importance of how historical processes of neighborhood occupation influence the distribution of spiders, demonstrating increased richness in areas with lower population densities, while other factors related to urban landscapes may be related to the distribution of ant and spider species.

A quick evaluation of ecological restoration based on arthropod communities and trophic guilds in an urban ecological preserve in Mexico City

BackgroundRestoration practices usually emphasize on the structural part of the biodiversity; also, most studies have focused on plants and very few have been conducted on arthropods and its function after restoration. The Pedregal de San Angel Ecological Reserve (PSAER) is a protected area immersed in Mexico City and it has been drastically affected by different anthropogenic disturbances. The aim of this study was to compare the relative diversity, richness, and abundance of species level identification, but also the composition through an analysis of ordination of taxonomic (species, family, and order level) and functional (trophic guild) traits of arthropods in three sites subjected to ecological restoration within the PSAER. Restored sites were also compared to conserved and disturbed sites, to evaluate whether restoration efforts are effective at the reserve.MethodsArthropods were sampled using pan traps during September 2013 in 11 sites (three restored, four conserved and four disturbed) inside the PSAER. All sampled species were taxonomically identified at species of morphospecies (inside a family) and assigned to a trophic guild. Differences in diversity, richness and abundance were evaluated through effective number of species, comparisons of Chao’s1 estimated richness and a non-parametric Kruskal–Wallis test, respectively. Both taxonomic and trophic guild composition were evaluated using a multivariate analysis and a post hoc test.ResultsWe found some differences in richness, abundance, and diversity between sites, but not a clear pattern of differentiation between restored to disturbed sites. The NMDS showed differences at species and order level, and with trophic guilds, among site types. Families were not useful to differentiate types of sites. Regarding guilds, predators were more abundant in conserved sites, while phytophagous insects were more abundant in disturbed sites.ConclusionsSpecies and order level were useful to identify differences in communities of arthropods in sites with different management. The trophic guild approach provides information about the functional state of the restored sites. Nevertheless, our quick evaluation shows that restoration efforts at PSAER have not been successful in differentiate restored to disturbed sites yet.

The Evolution of Microbial Facilitation: Sociogenesis, Symbiogenesis, and Transition in Individuality

Metabolic cooperation is widespread, and it seems to be a ubiquitous and easily evolvable interaction in the microbial domain. Mutual metabolic cooperation, like syntrophy, is thought to have a crucial role in stabilizing interactions and communities, for example biofilms. Furthermore, cooperation is expected to feed back positively to the community under higher-level selection. In certain cases, cooperation can lead to a transition in individuality, when freely reproducing, unrelated entities (genes, microbes, etc.) irreversibly integrate to form a new evolutionary unit. The textbook example is endosymbiosis, prevalent among eukaryotes but virtually lacking among prokaryotes. Concerning the ubiquity of syntrophic microbial communities, it is intriguing why evolution has not lead to more transitions in individuality in the microbial domain. We set out to distinguish syntrophy-specific aspects of major transitions, to investigate why a transition in individuality within a syntrophic pair or community is so rare. We review the field of metabolic communities to identify potential evolutionary trajectories that may lead to a transition. Community properties, like joint metabolic capacity, functional profile, guild composition, assembly and interaction patterns are important concepts that may not only persist stably but according to thought-provoking theories, may provide the heritable information at a higher level of selection. We explore these ideas, relating to concepts of multilevel selection and of informational replication, to assess their relevance in the debate whether microbial communities may inherit community-level information or not.

Fungal Community Development in Decomposing Fine Deadwood Is Largely Affected by Microclimate.

Fine woody debris (FWD) represents the majority of the deadwood stock in managed forests and serves as an important biodiversity hotspot and refuge for many organisms, including deadwood fungi. Wood decomposition in forests, representing an important input of nutrients into forest soils, is mainly driven by fungal communities that undergo continuous changes during deadwood decomposition. However, while the assembly processes of fungal communities in long-lasting coarse woody debris have been repeatedly explored, similar information for the more ephemeral habitat of fine deadwood is missing. Here, we followed the fate of FWD of Fagus sylvatica and Abies alba in a Central European forest to describe the assembly and diversity patterns of fungal communities over 6 years. Importantly, the effect of microclimate on deadwood properties and fungal communities was addressed by comparing FWD decomposition in closed forests and under open canopies because the large surface-to-volume ratio of FWD makes it highly sensitive to temperature and moisture fluctuations. Indeed, fungal biomass increases and pH decreases were significantly higher in FWD under closed canopy in the initial stages of decomposition indicating higher fungal activity and hence decay processes. The assembly patterns of the fungal community were strongly affected by both tree species and microclimatic conditions. The communities in the open/closed canopies and in each tree species were different throughout the whole succession with only limited convergence in time in terms of both species and ecological guild composition. Decomposition under the open canopy was characterized by high sample-to-sample variability, showing the diversification of fungal resources. Tree species-specific fungi were detected among the abundant species mostly during the initial decomposition, whereas fungi associated with certain canopy cover treatments were present evenly during decomposition. The species diversity of forest stands and the variability in microclimatic conditions both promote the diversity of fine woody debris fungi in a forest.

A nonanalog Pliocene ungulate community at Laetoli with implications for the paleoecology of Australopithecus afarensis

The dietary guild structure of ungulate communities is a useful paleoecological tool for understanding the context of hominin paleobiology and evolution. Ungulates are well represented in the fossil record, and their dietary preferences reflect those of major habitat types. However, paleoecology relies on modern ecological patterns as analogs for recreating ecologies of the past. It has previously been suggested that for much of the Pliocene, no such modern analogs exist for the herbivore communities associated with hominins in eastern Africa. This study aims to determine whether the ungulate community associated with A. afarensis at the Pliocene site of Laetoli, Tanzania, shares similarities with extant communities or whether it lacks a modern analog. Our multiproxy approach using mesowear, hypsodonty, and stable carbon isotopes of tooth enamel to infer the diets of ungulates in the Upper Laetolil Beds shows that this community is dominated by browsers and mixed feeders and has a very low prevalence of grazers and frugivores. This dietary guild composition distinguishes the Upper Laetolil Beds from modern African communities and suggests either that the Upper Laetolil Beds had a unique vegetation structure which was able to support a higher diversity of browsing ungulates than that exists in African ecosystems today or that it retained an ungulate community that was resilient to environmental change. The Upper Laetolil Beds ungulate community is also unique relative to other mid-Pliocene communities in eastern Africa, some of which are similar to extant communities, while others, such as Laetoli, lack modern counterparts. This suggests that A. afarensis was a eurytopic species that inhabited a variety of ecosystems, including those with and without modern analogs. The co-occurrence of both analog and nonanalog communities in the Pliocene suggests that the transformation toward ungulate communities of modern aspect occurred asynchronously in eastern Africa.

Avian diversity and abundance across years: consistent patterns in forests but not grasslands on Viti Levu, Fiji

Context Habitat loss is a global problem and in Fiji >50% of the land area once covered by forests has been converted to grasslands and agricultural land. About 99% of Fiji’s endemic biodiversity and 80% of the land bird species have been identified as forest species. Aims In this study, we compare forest and grassland sites and test for consistency in avian diversity, abundance, foraging guild, and distribution status (endemic, native, introduced to Fiji) over a 5-year period (2016–2020). Methods We surveyed bird communities using the point count method with a 100 m radius and 7-min observation period per site. Key results A one-way analysis of similarities (ANOSIM) analysis showed significant differences in species composition and bird abundance between the forested habitats and grassland habitats. A general linear model test showed significant differences in foraging guild composition and distribution status between forested and grassland habitats. There were no significant differences between the three forested sites (primary montane forest, secondary old-growth forest, old-growth mahogany plantations with regenerating native species), while grassland sites had stronger annual change in species composition. Implications Forest cover, irrespective of whether these forests are of primary or secondary nature, therefore plays an important role in maintaining the native and endemic land bird species and other biodiversity in oceanic island ecosystems such as Viti Levu Island, Fiji.

Drivers of fish trophic guild composition in lakes of the Upper Paraná River floodplain

Drivers of fish trophic guild composition in lakes of the Upper Paraná River floodplain

The Impact of the Neophyte Tree Fraxinus pennsylvanica [Marshall] on Beetle Diversity under Climate Change

We studied the impact of the neophyte tree Fraxinus pennsylvanica on the diversity of beetles in floodplain forests along the river Elbe in Germany in 2016, 2017 and in 2020, where 80% of all Fraxinus excelsior trees had died following severe droughts. Beetles were collected by insecticidal knock-down from 121 trees (64 F. excelsior and 57 F. pennsylvanica) and identified to 547 species in 15,214 specimens. The trees sampled in 2016 and 2017 showed no signs of drought stress or ash dieback and serve as a reference for the comparison with the 2020 fauna. The data proved that F. excelsior harbours the most diverse beetle community, which differed also significantly in guild composition from F. pennsylvanica. Triggered by extremely dry and long summer seasons, the 2020 ash dieback had profound and forest-wide impacts. Several endangered, red-listed beetle species of Saxonia Anhalt had increased in numbers and became secondary pests on F. excelsior. Diversity decreased whilst numbers of xylobionts increased on all trees, reaching 78% on F. excelsior. Proportions of xylobionts remained constant on F. pennsylvanica. Phytophages were almost absent from all trees, but mycetophages increased on F. pennsylvanica. Our data suggest that as a result of the dieback of F. excelsior the neophyte F. pennsylvanica might become a rescue species for the European Ash fauna, as it provides the second-best habitat. We show how difficult it is to assess the dynamics and the ecological impact of neophytes, especially under conditions similar to those projected by climate change models. The diversity and abundance of canopy arthropods demonstrates their importance in understanding forest functions and maintenance of ecosystem services, illustrating that their consideration is essential for forest adaptation to climate change.

The effect of body size on co‐occurrence patterns within an African carnivore guild

Intraguild interactions among mammalian carnivores are important in shaping carnivore guild composition. Competing species may inhabit different areas and/or being active during different times to reduce the risk of aggressive interactions, but the role of body size in intraguild interactions within carnivore guilds remains largely unknown. We determined spatial and temporal co‐occurrence of small, medium‐sized and large carnivores of the carnivore guild in central Tuli, Botswana: lion Panthera leo, leopard Panthera pardus, spotted hyena Crocuta crocuta, brown hyena Parahyaena brunnea, black‐backed jackal Canis mesomelas, bat‐eared fox Otocyon megalotis, African wildcat Felis sylvestris lybica, African civet Civettictis civetta, honey badger Mellivora capensis and small‐spotted genet Genetta genetta. We used camera trap data over a two‐year period and quantified the degree of temporal and spatial overlap by comparing activity patterns and calculating Pianka's index respectively. Our results showed that temporal overlap in activity between all carnivore species was high, but complete overlap was possibly reduced by differences in peak activity periods. In addition, low to moderate levels of spatial overlap were found between the different carnivore species, supporting the idea that small carnivore species inhabit different areas than large species to reduce the risk of interference competition. Due to the possible strong competition amongst sympatric carnivores there is a need for more knowledge on co‐existence patterns for successful management and conservation of carnivore species, for example when carnivore species are (re)introduced in an area.

Effects of microtopography on soil fungal community diversity, composition, and assembly in a subtropical monsoon evergreen broadleaf forest of Southwest China

Topography is a critical factor that determines the patterns and assemblages of species diversity in forest communities. Small-scale topography changes are defined as microtopography. Our understanding of the effects of microtopography on soil fungal communities is limited. The objective of this study was to explore the impact of microtopography on soil fungal community diversity, community composition, functional guild, and community assembly. The diversity, composition, and relative abundance of functional guilds were measured using Illumina high-throughput sequencing techniques in five microtopography types (steep slope, less-steep slope, valley, high plateau, and ridge). OTU and Chao1 indexes were the highest in the high plateau and were the lowest in the ridge. The Shannon index was the lowest in the valley, and the highest in the ridge. In the valley, soil fungal networks were more interconnected than they were in any of the other microtopography unit. At the class level, the relative abundance of Agaricomycetes, Eurotionmycetes, and Leotiomycetes were higher in the ridge unit. The relative abundance of ectomycorrhiza, the dominant functional guild, in the ecosystem was as follows: less-steep slope (71.31%), ridge (66.55%), valley (65.83%), steep slope (63.91%), and high plateau (60.09%). Microtopography influenced fungal community diversity and composition more than any other factor and had, varying degrees of influence on the different functional guilds. In every microtopography type, dispersal limitations and drift shaped fungal communities more than other ecological processes. Our findings suggest that microtopography affects soil fungal community diversity and composition, functional guilds, and the relative contributions of ecological processes to soil fungal communities in subtropical monsoon evergreen broadleaf forests.

Ground-dwelling Spider Communities Respond to Changes in Riparian Vegetation Widths.

Spiders play a key role in the ecological dynamics in riparian habitats. However, most studies on the effects of changes in riparian habitats on spider communities have focused on the conversion of riparian forest to other land uses rather than on a gradient of forest widths. We assessed the community structure of ground-dwelling spiders in riparian vegetation fragments with varying widths in Southern Brazil. We selected four fragments with different riparian vegetation widths (> 40 m; < 30 m; < 15 m; < 5 m). In each fragment, spiders were seasonally collected using pitfall traps. We tested the effects of riparian vegetation widths and environmental variables (litter height, litter cover and canopy openness) on the taxonomic and guild composition of spider communities. The taxonomic and guild composition of ground-dwelling spiders varied among the widest (> 40 and < 30 m) and narrower riparian widths (< 15 m and < 5 m). While hunting spiders were associated with the narrower widths, web-building spiders were associated with the wider widths. Spider composition was influenced by the leaf litter height in the widest widths (> 40 and < 30 m) and by canopy openness in the narrowest width (< 15 m). Reductions in riparian vegetation were associated with significant changes in the community structure of ground-dwelling spiders, likely through top-down mechanisms associated with the higher litter input in wider fragments. In summary, the fragmentation of the riparian forests of Sothern Brazil are negatively associated with web-building spiders.