Diversity Patterns Of Communities Research Articles

Seasonal variations in soil microbial community co-occurrence network complexity respond differently to field-simulated warming experiments in a northern subtropical forest

Global warming may reshape seasonal changes in microbial community diversity and co-occurrence network patterns, with significant implications for terrestrial ecosystem function. We conducted a 2-year in situ field simulation of the effects of warming on the seasonal dynamics of soil microbial communities in a northern subtropical Quercus acutissima forest. Our study revealed that warming had no significant effect on the richness or diversity of soil bacteria or fungi in the growing season, whereas different warming gradients had different effects on their diversity in the nongrowing season. Warming also changed the microbial community structure, increasing the abundance of some thermophilic microbial species and decreasing the abundance of some symbiotrophic microorganisms. The co-occurrence network analysis of the microbial community showed that warming decreased the complexity of the intradomain network in the soil bacterial community in the growing and nongrowing seasons but increased it in the fungal community. Moreover, increasing warming temperatures increased the complexity of the interdomain network between bacteria and fungi in the growing season but decreased it in the nongrowing season, and the keystone species in the interdomain network changed with warming. Warming also reduced the proportion of positive microbial community interactions, indicating that warming reduced the mutualism, commensalism, and neutralism of microorganisms as they adapted to soil environmental stress. The factors affecting the fungal community varied considerably across warming gradients, with the bacterial community being significantly affected by soil temperature, MBC, NO3−-N and NH4+-N, moreover, SOC and TN significantly affected fungal communities in the 4 °C warming treatment.. These results suggest that warming increases seasonal differences in the diversity and complexity of soil microbial communities in the northern subtropical region, significantly influencing soil dynamic processes regulating forest ecosystems under global warming.

Unveiling soil animal community dynamics beneath dominant shrub species in natural desert environment: Implications for ecosystem management and conservation

The Taklimakan Desert, known for extreme aridity and unique ecological challenges, maintains a delicate life balance beneath its harsh surface. This study investigates intricate dynamics of soil animal communities within this desert ecosystem, with a particular focus on vertical profile variations beneath four dominant shrub species (AS-Alhagi sparsifolia, KC-Karelinia caspia, TR- Tamarix ramosissima, CC- Calligonum caput-medusae). Utilizing comprehensive soil sampling and metagenomics techniques, we reveal the diversity and distribution patterns of soil animal communities from the soil surface down to deeper layers (0–100 cm). Our research outcomes have unveiled that Nematoda and Arthropoda emerge as the most predominant classes of soil animals across all studied shrubs. Specifically, Nematoda exhibited notably high abundance in the KC area, while Arthropoda thrived predominantly in the TR region. We also observed a linear decrease in Nematoda populations as soil depth increased, consistent among all shrub species. Moreover, the highest Shannon diversity within soil animal communities was recorded in the KC area, underscoring a trend of declining alpha diversity in the AS region and an increase in other shrub areas as soil depth increased. Notably, the zones dominated by CC and TR displayed the highest levels of beta diversity. Our correlation analysis of soil animals and environmental factors has pinpointed soil water content, available phosphorus, and available potassium as the most influential drivers of variations in the top-classified soil animal communities. This study provides insights into soil animals in deserts, supporting future research to preserve these fragile deserts and enhance our understanding of life below the surface in challenging ecosystems.

Symbiont community dynamics in the turbid reef specialist, Turbinaria reniformis, along a latitudinal and environmental gradient in Western Australia

AbstractThermal stress triggers the breakdown of the obligate symbiosis between the cnidarian coral host and its autotrophic dinoflagellates of the family Symbiodiniaceae. This diverse family exhibits pronounced functional variation that has large implications for the survival of their coral host. In this study, we explored patterns of symbiont community composition and diversity in the coral Turbinaria reniformis, a turbid reef specialist, along a latitudinal and environmental gradient in Western Australia. Using metabarcoding of the internal transcribed spacer region 2, we explored symbiont community patterns, their environmental drivers, and potential associations with host genetic structure. Our findings reveal a predominance of Cladocopium across our study area, with distinct regional composition influenced primarily by sea surface temperature. Geographical distance and host genetic data did not align with symbiont community divergence, suggesting a complex interplay of environmental and genetic factors t shaping the community structure. This study underscores Cladocopium stability in Western Australia across large distances and strong environmental gradients. It also highlights the highly diversified lineage community that may explain T. reniformis ability to thrive in a wide range of environmental conditions.

Regional diversity and spatial patterns of epibenthic communities in the Laurentian Channel Marine Protected Area

Megafauna, such as cold-water corals, can promote diversity through various processes, such as predation, bioturbation, competition, and facilitation as habitat engineers. Further investigation into their ecology and role in epifaunal community structure in the deep sea is needed. Diversity, abundance, and spatial patterns of epibenthic megafauna (≥ 2 cm) were quantified at regional-scales (100s m – 100s km) using high-resolution imagery from 15 stations in the Laurentian Channel Marine Protected Area, Canada. A patchy community structure was significantly associated with station and benthoscape class, which in turn was based on geological factors. Three types of assemblages included: (1) dominated by corals Pennatula sp. 2 and/or Hexacorallia (SC.) spp. in shallow eastern benthoscape classes with high abundance and low diversity; (2) a diverse mix of taxa (e.g. sea pens Anthoptilum spp. and Kophobelemnon spp., anemones/cerianthids, etc.) in deeper (> 400 m) western benthoscapes, with low abundance and high diversity; and (3) a unique community dominated by sponges. Overall, eight taxa contributed to most dissimilarities between stations, and communities were similar within 10 km but could differ at greater distances. Benthoscape classes captured environmental factors (e.g. depth and substrate) that may be responsible for changes in diversity and abundance, and are used as a proxy for different habitats. Our study advanced the understanding of regional spatial patterns in the abundance, composition, and diversity of epibenthic communities, by identifying spatial patterns particularly in the Laurentian Channel where data were limited, adding to interpretations of spatial ecology in a previous fine-scale study. Additionally, these spatial patterns reflect various underlying ecological processes that are mostly unknown. Our community analysis and observed changes in abundance and diversity have implications that can help inform future monitoring designs to promote representative and meaningful spatial assessments.

Tidal restriction does not always supplant local conditions shaping estuarine plant communities

Salt marshes are a common feature of temperate estuaries and represent the world's most abundant wetland type. They also harbour very productive plant communities and provide numerous ecosystem services. In an anthropized setting, we aimed at describing the effect of tidal restriction on the diversity patterns of vegetation communities, and to link them to the physical and chemical parameters of the estuary's oligohaline marshes.The tidal marshes of the Seine Estuary in northern France display long-lasting human activities that have shaped the ecological processes of the river Seine and its associated marshes. One of the estuary's distinctive features is a dyke on the north shore, isolating the wetlands behind it from direct tidal regimes. These areas are submitted to flooding through water gates, but tidal restriction is known to alter ecosystem processes and to possibly modify vegetation communities. Over the course of three years, we have surveyed the vegetation communities and soil parameters of three levels along the topographical gradients of two sites under tidal restriction and one site under tidal influence, with cases of mowing and grazing.Overall species richness increased along the elevation gradient, as abiotic constraints are lifted. Decomposition of species turnover (beta diversity) revealed different replacement dynamics, with tidal restriction being associated with species replacement rather than abundance difference. Tidal restriction was also associated with higher temporal stability. Canonical Correspondence Analysis between vegetation and soil surveys revealed that topography, soil pH, conductivity and soil organic carbon explained most of the differences between vegetation communities. Higher elevation vegetation plots converged, regardless of tidal restriction or land-use, while lower elevation plots diverged between study sites.We found that tidal restriction attenuated the abiotic constraints on one site, while creating new constraints linked to freshwater retention on the other site. In addition, tidal restriction was associated with longer elevational gradients compared to the connected site. Tidal restriction might therefore be a valuable management tool for estuarine marshes, as well for restoration purposes as for the mitigation of future effects related to climate change induced sea level rise.

Effects of lactic acid bacteria on rearing water bacterial community in Eriocheir sinensis culture.

The Chinese mitten crab (CMC, Eriocheir sinensi) culture in ponds is a unique aquaculture system. Probiotics are commonly used in the maintenance of the health of pond-cultured CMCs. However, the effects of probiotics on the bacterial community of CMC-culturing water remain unclear. This study utilized 16S rRNA gene amplicon sequencing to assess changes in the bacterial community composition, diversity, assembly, and co-occurrence patterns in CMC-culturing water following probiotic application. The results indicate that the α-diversity of the bacterial community in CMC-culturing water varied with time following probiotic application. The addition of probiotics to the water resulted in an increase in the occurrence of new OTUs. The bacterial community assembly in the CMC-culturing water was shaped by a balance between deterministic and stochastic processes, while commercial probiotics enhanced the proportion of heterogeneous selection. In addition, including OTU2953 (Burkholderiaceae) and OTU3005 (Lactobacillaceae), from the commercial probiotics served as keystone species in the bacterial network of CMC-culturing water. Overall, probiotic application had a significant impact on the bacterial ecology of CMC-culturing water.

Macroecological patterns of functional and phylogenetic diversity vary between ground and arboreal assemblages in Neotropical savanna ants

Macroscale environmental gradients can have contrasting effects on organisms that occupy different vertical niches, but we have little understanding of how this might result in different macroscale diversity patterns in ground and arboreal communities. We also have little understanding of how different dimensions of diversity, such as functional and phylogenetic diversity, vary along macroscale environmental gradients. Here we examine latitudinal and elevational patterns of different dimensions of diversity for both ground and arboreal assemblages in Neotropical savanna ants. The study was based on ant species occurring at 32 sites covering a 22° range of latitude and > 1000 m range in elevation in Brazil. Functional and phylogenetic richness were positively correlated with species richness, all increasing with latitude. However, the greater phylogenetic richness on the ground than in trees did not simply reflect differences in species richness. The mean functional and phylogenetic divergence among species was also greater on the ground than in trees, indicating a stronger role of competition. Both mean functional and phylogenetic divergence showed negative correlations with elevation in trees but not on the ground. In trees, the standardized effect size (taking into account differences in species richness) of mean functional divergence was negatively related to elevation and mean phylogenetic divergence was negatively related to both latitude and elevation. These findings suggest that as temperature decreases the relative importance of environmental filtering in arboreal but not ground communities increases (and that of competition and niche partitioning decreases). Overall, we show that the macroecological patterns of ant species richness that have previously been reported for Brazilian savannas do not adequately represent other dimensions of diversity, and that the representativeness differs between vertical strata. Macroecological patterns of functional and phylogenetic divergence indicate that the relative importance of competition and environmental filtering also differs between vertical strata.

Patterns and processes underlying understory songbird communities in southern China

AbstractUnderstory bird communities, especially those comprising insectivores, are highly sensitive to forest loss and fragmentation. Currently, there is little knowledge regarding the large‐scale diversity patterns of understory bird communities, particularly in Eastern Asia. Consequently, we aimed to identify the distribution patterns of understory birds in southern China and the factors underlying these patterns. We analysed the diversity distribution patterns of taxonomic and functional α and β diversity for understory Passeriformes birds in southern China utilising cluster and ordination analyses. Subsequently, we analysed the effects of geographic distance, annual mean temperature, annual temperature range, annual mean precipitation, and annual precipitation range on diversity distribution patterns. In total, 9282 individuals belonging to 11 orders, 48 families, and 297 species were captured over 98,544 net hours, with Alcippeidae being the most abundant family in southern China. The understory bird communities of the 25 sites were categorised into six sub‐regions of the Oriental Realm (Indo‐Malayan Realm). The pattern in the distribution of taxonomic and functional β‐diversity of understory birds in southern China was consistent with zoogeographical regionalisation. Three distinct geographical groups were identified: Group 1 was located in the Min‐Guang Coast and Hainan sub‐regions; Group 2 was located in the East Hilly Plain, Southwest Mountains, and Western Mountains and Plateaus sub‐regions; and Group 3 was located in the Southern Yunnan Mountain subregion. The most critical factors related to the distribution patterns of β‐diversity were geographical distance, annual mean temperature, and annual temperature range. Our results showed that the understory bird communities of the Southwest Mountain, East Hilly Plain, and Western Mountains, and Plateaus sub‐regions were similar, as were those of the Min‐Guang Coast and Hainan sub‐regions. Our results underscore the joint roles of distance, temperature, and historical evolution in understory bird communities.

Biogeography and diversity patterns of abundant and rare bacterial communities in paddy soils along middle and lower Yangtze River.

The middle and lower reaches of the Yangtze River serve as principal rice production bases in China, yet the biodiversity and ecological processes of bacterial communities in paddy soils are not well understood. This study explores the diversity, composition, ecological function, and assembly processes of abundant and rare bacterial communities in paddy soils. A total of 129 paddy soil samples from 43 sites along the middle and lower reaches of the Yangtze River were collected and analyzed using NovaSeq sequencing. The results showed that the dominant phylum for both abundant and rare taxa was Proteobacteria, with a greater relative abundance of the abundant taxa. The diversity of the abundant community was lower than that of the rare community. Soil properties and geographic variables explained more of the variation in the abundant community than in the rare community. The rare community exhibited a significant distance-decay relationship. The assembly of the abundant community was more influenced by stochastic processes, although both the abundant and rare communities were governed by stochastic processes. It is concluded that both abundant and rare bacterial communities exhibit differing biogeographic patterns, yet they undergo similar ecological processes in the paddy soils along the middle and lower reaches of the Yangtze River. These observations offer a theoretical framework for a deeper comprehension of the function of both abundant and rare bacteria, as well as the development and preservation of soil bacterial diversity within agricultural ecosystems.

Intraspecific plant-soil feedback in four tropical tree species is inconsistent in a field experiment.

Soil microbes can influence patterns of diversity in plant communities via plant-soil feedbacks. Intraspecific plant-soil feedbacks occur when plant genotype leads to variations in soil microbial composition, resulting in differences in the performance of seedlings growing near their maternal plants versus seedlings growing near nonmaternal conspecific plants. How consistently such intraspecific plant-soil feedbacks occur in natural plant communities is unclear, especially in variable field conditions. In an in situ experiment with four native tree species on Barro Colorado Island (BCI), Panama, seedlings of each species were transplanted beneath their maternal tree or another conspecific tree in the BCI forest. Mortality and growth were assessed at the end of the wet season (~4 months post-transplant) and at the end of the experiment (~7 months post-transplant). Differences in seedling performance among field treatments were inconsistent among species and eroded over time. Effects of field environment were detected at the end of the wet season in two of the four species: Virola surinamensis seedlings had higher survival beneath their maternal tree than other conspecific trees, while seedling survival of Ormosia macrocalyx was higher under other conspecific trees. However, these differences were gone by the end of the experiment. Our results suggest that intraspecific plant-soil feedbacks may not be consistent in the field for tropical tree species and may have a limited role in determining seedling performance in tropical tree communities. Future studies are needed to elucidate the environmental and genetic factors that determine the incidence and direction of intraspecific plant-soil feedbacks in plant communities.

Elevation differentially shapes functional diversity patterns in understorey forest communities when considering intraspecific and interspecific trait variability

AbstractQuestionsWhat is the relative importance of interspecific and intraspecific trait variation and their covariation in the herb layer of European temperate beech forests, and how do they vary with elevation? Is there evidence of interspecific trait convergence at higher elevations, as postulated by the habitat‐filtering hypothesis, and is this convergence enhanced or counteracted by intraspecific variation?LocationNational Park “Foreste Casentinesi, Monte Falterona and Campigna”, Italy.MethodsWe measured four functional traits – plant height, specific leaf area (SLA), leaf dry matter content (LDMC) and leaf area – across 775 individuals from 60 herb‐layer species in 28 forest plots (10 m × 10 m) spanning an 800 m elevation gradient. For each trait in each plot, we computed community‐weighted means (CWMs) and the standardized effect size of functional diversity (SES‐FD). We decomposed total trait variation into its interspecific and intraspecific components, and their covariation. We run linear regression models to assess the impact of elevation on these three components of functional variation. Lastly, we investigated whether higher elevation communities exhibited lower SES‐FD, indicating functional convergence that could hint to a stronger habitat filtering.ResultsInterspecific trait variation was more important than the intraspecific counterpart both for CWMs and SES‐FD. Only CWMs calculated for plant height and LDMC showed a significant relationship with elevation. Low‐elevation communities featured taller, more‐conservative species, whereas shorter, faster‐growing species were more common at higher elevations. SES‐FD remained consistently negative for species turnover and total variation, suggesting stable functional convergence across the gradient.ConclusionsOur findings suggest that interspecific and intraspecific trait variability can be decoupled along an elevation gradient, stressing the importance of individually considering each component of trait variation when studying community composition. Elevation significantly influenced various components of plant community trait variation, with habitat filtering playing a substantial role in selecting plants with specific traits across elevations.

Patterns of forest community diversity, regeneration potential and carbon storages along an altitudinal gradient in Eastern Himalaya, India

This study showed changing patterns in the plant species composition, diversity, and carbon storage potential of different forests along altitudinal gradients (i.e. 100 – 1900 m) in Eastern Himalayan India. Different tree, shrub and herb species were sampled along the altitudinal gradients ranging from tropical to temperate forests through Nested Plot design. In each forest, vegetation sampling was made by establishing a permanent plot of 250 m × 250 m as per ISRO-GBP/NCP-VCP protocol. Individuals of trees ≥10 cm girth at breast height (GBH), shrubs and herbs were recorded in 4, 8 and 16 subplots of 31.62 m × 31.62 m, 5 m × 5 m and 1 m × 1 m, respectively. Community attributes such as species richness, density, basal area, diversity indices and biomass and carbon storages were computed for each study site. A total of 5 forest communities (2 each from tropical and subtropical and one from temperate forest) were identified. The woody species diversity was highest in the subtropical forest followed by tropical and temperate forest. Altitude played an important role in the Eastern Himalayan Mountains in the establishment and distribution of forest community. Forest community composition changes with elevation, for instance, the dominant communities like Dipterocarpus retusus–Phoebe goalparensis–Schima wallichii (D-P-S), Gmelina arborea–Schima wallichii-Duabanga grandiflora (G-S-D), Schima wallichii–Duabanga grandiflora–Alstonia scholaris (S-D-A), Alstonia scholaris–Terminalia myriocarpa–Bischofia javanica (A-T-B) and Acer thomsonii–Rhodendron arboreum–Quercus lamellose (A-R-Q) were present at elevational ranges of 100–300 m, 300–700 m, 700–1100 m, 1100–1500 m and 1500–1900 m, respectively. The study showed that about 41–57% of the tree species exhibited good regeneration followed by 23–30% as fair, 6–16% as poor, and 6–21% species did not show regeneration along the altitudinal gradient. The total biomass carbon (Mg C ha−1) varied from 84.74 to 163.56 in tropical, 103.12 – 156.41 in subtropical and 133.05 in temperate forest. In conclusion, community composition, regeneration pattern and biomass carbon storage changes along altitude because of altered biophysical characteristics. However, despite variations in elevation, factors for forest disturbance at different altitudes significantly contributed to the community attributes and overall accumulation of biomass carbon. Hence, the traditional management practices carried out by local communities also play a crucial role in shaping the structure, composition, and carbon dynamics of forest ecosystems. Understanding the impacts of these practices is essential for promoting sustainable forest management by conserving forests and preserving carbon stocks for mitigating climate change in future. This study emphasizes the importance of long-term forest monitoring to promote biodiversity conservation and formulate conservation strategies that support sustainable forest management policies to which ensure continuous provision of ecosystem services in the region.

Influences of the Integrated Rice-Crayfish Farming System with Different Stocking Densities on the Paddy Soil Microbiomes.

Integrated rice-fish farming has emerged as a novel agricultural production pattern to address global food security challenges. Aiming to determine the optimal, scientifically sound, and sustainable stocking density of red claw crayfish (Cherax quadricarinatus) in an integrated rice-crayfish farming system, we employed Illumina high-throughput 16S rRNA gene sequencing to evaluate the impact of different stocking densities of red claw crayfish on the composition, diversity, function, and co-occurrence network patterns of soil bacterial communities. The high stocking density of red claw crayfish reduced the diversity and evenness of the soil bacterial community during the mid-culture stage. Proteobacteria, Actinobacteria, and Chloroflexi emerged as the most prevalent phyla throughout the experimental period. Low stocking densities initially boosted the relative abundance of Actinobacteria in the paddy soil, while high densities did so during the middle and final stages. There were 90 distinct functional groups identified across all the paddy soil samples, with chemoheterotrophy and aerobic chemoheterotrophy being the most abundant. Low stocking densities initially favored these functional groups, whereas high densities enhanced their relative abundances in the later stages of cultivation. Medium stocking density of red claw crayfish led to a more complex bacterial community during the mid- and final culture stages. The experimental period showed significant correlations with soil bacterial communities, with total nitrogen (TN) and total phosphorus (TP) concentrations emerging as primary factors contributing to the alterations in soil bacterial communities. In summary, our findings demonstrated that integrated rice-crayfish farming significantly impacted the soil microbiomes and environmental factors at varying stocking densities. Our study contributed to theoretical insights into the profound impact of integrated rice-crayfish farming with various stocking densities on bacterial communities in paddy soils.

Impacts of cadmium accumulation on the diversity, assembly processes, and co-occurrence patterns of archaeal communities in marine sediments

There is limited understanding regarding the changes in the ecological processes and the mechanisms of archaeal community in response to heavy metal contamination in the marine sediments. In this study, sediment samples were collected from 46 locations near harbors, and the concentration of heavy metals and the diversity of archaeal communities were investigated to understand the impact of Cd on archaeal communities. The results demonstrated a significant correlation between the diversity of archaeal community and Cd concentration, particularly showing a linear decrease in the species richness with rising Cd concentration. ANME-1b was identified as a significantly enriched archaeal taxon in the higher Cd environment. Null model and neutral community model indicated that the ecological assembly of archaeal communities in marine sediments was primarily governed by the stochastic processes, with dispersal limitation being the primary factor. The contribution of deterministic process to the assembly of archaeal communities in higher Cd environments increased clearly, accompanied by a notable reduction in species migration rates and widths of ecological niche of archaeal populations. Co-occurrence network analysis revealed an obvious increase in species interactions in higher Cd environments, with an apparent rise in the proportion of competitive relationships and an increase in the number of keystone species. Moreover, archaeal species formed a more complex and stable community to cope with Cd stress. This study provides new insights into the impacts of heavy metals on the ecological processes of marine microorganisms and the underlying mechanisms.

Rehydration under extreme drought conditions affected rhizosphere microorganisms more than bulk soil in broomcorn millet farmland

Rehydration is a primary adaptation strategy for alleviating the detrimental effects of drought on crop growth. However, the effects of rehydration on microbial communities in various compartments under drought conditions remain poorly understood. Herein, we explored the response patterns of bacterial and fungal community composition, diversity, ecological network, and assembly process in the bulk soil and rhizosphere of broomcorn millet farmland at 5, 10, 20, and 30 days after rehydration during drought conditions. Compared to drought, rehydration significantly decreased the organic matter (OM), total nitrogen (TN), available potassium (AK), available phosphorus (AP), nitrate nitrogen (NO3--N), and ammonium nitrogen (NH4+-N) contents in rhizosphere, but had no obvious influences on the OM and TN contents in bulk soil on the four sampling days. In the rhizosphere of broomcorn millet field, Firmicutes and Actinobacteria were enriched in drought condition, but Proteobacteria and Bacteroidetes were enriched in rehydration regime. Compared to drought, the relative abundances of Eurotiomycetes, Dothideomycetes, Mortierellomycetes, and Leotiomycetes were enhanced, but Sordariomycetes was reduced on the 5th and 10th days after rehydration. Rehydration increased the bacterial and fungal observed ASVs and Shannon index in the rhizosphere to varying degrees, but had little effect on the bulk soil. Null-model analysis indicated that rehydration deceased the stochastic process of fungal communities in the bulk soil, whereas had no influence on deterministic process of bacterial community in the bulk soil and rhizosphere. More importantly, rhizosphere properties had a greater impact on the bacterial and fungal community composition, diversity, and assembly process than bulk soil. Network analysis revealed that rehydration improved the interconnected taxa in the rhizosphere bacterial network, but reduced microbial interactions in the rhizosphere fungal network compared to drought. This work provides a theoretical foundation for elucidating the role of rehydration regime in governing the ecological services of microbiome of broomcorn millet farmland under drought conditions.

Response of functional diversity of fish communities to habitat alterations in small lowland rivers

AbstractFunctional diversity has proven to be more responsive than traditional taxonomic diversity to alterations for a wide set of communities, especially in aquatic ecosystems. Habitat alterations are among the most relevant causes of biodiversity loss in freshwater ecosystems, nevertheless their effect on functional diversity has been scarcely investigated so far. In this study, functional diversity of fish communities in the River Po basin, north Italy, were related to habitat quality at different spatial scales. Land use and riparian vegetation were identified as the most influent factors on freshwater fish functional diversity. On the other hand, habitat descriptors at smaller scale did not influence functional diversity of fish. The evidenced responses were driven by the contribution of exotic species, which maximized ecological niche occupancy, either by exploiting increased habitat heterogeneity or by interaction with native species. Moreover, traits filtering, disadvantaging large predators such as salmonids, was also observed in the studied communities, but likely this effect was related to other factors than habitat alterations. Overall, this study confirms that land use changes can be considered as valid proxies for anthropogenic alterations. Moreover, possible effects at ecosystem level, also related to the spread of exotic species, could be hypothesized, giving that traits mostly influencing the observed patterns of diversity in communities were related to trophic niche, a factor that has been associated with crucial processes like nutrient cycling or energy transfer.

Plant spectral diversity from high‐resolution multispectral imagery detects functional diversity patterns in coastal dune communities

AbstractQuestionRemote sensing is a fundamental tool to monitor biodiversity and spectral diversity may represent a proxy for different biodiversity facets such as taxonomic (TD) and functional diversity (FD). We used fine‐resolution multispectral imagery to explore spectral diversity (SD) patterns across spatial scales (i.e., plot, transect, area), and assess SD relationships with TD and FD along an environmental gradient.LocationCoastal sand dune, Viareggio, Italy (“Migliarino–San Rossore–Massaciuccoli” Regional Park, 43°83′ N, 10°25′ E).MethodsWe measured TD as species richness, while SD and FD were computed using probability density functions based on pixel and species position in multivariate spaces. We compared SD and FD patterns in space occupation, and we tested whether these patterns are coordinated along the sea–inland gradient. We also assessed univariate relationships between SD and biodiversity facets, and we tested how these facets were partitioned across scales.ResultsWe found a strong correspondence between functional and spectral patterns in space occupation and along the environmental gradient, with a lack of significance when considering TD. However, TD and SD showed higher variation at broader scale while most FD variation occurred at plot level.ConclusionBy measuring FD and SD with a common methodological framework, we demonstrate that SD approximates functional patterns in plant communities. Moreover, we show that SD retrieved using high‐resolution images can capture different aspects of FD, and that the occupation of the spectral space is analogous to the occupation of the functional space.

Responses of multi-faceted benthic macroinvertebrates alpha and beta diversity to flooding in a highland floodplain

Flooding is an important process in natural fluvial floodplains. How the flood shapes aquatic community diversity in highland floodplains is still poorly understood. The aim of this study was to unravel the multi-faceted responses of benthic macroinvertebrate diversity to flooding and habitat environments in the Baihe River Basin from a taxonomic, phylogenetic, and functional perspective. We examined the alpha and beta diversity patterns of benthic macroinvertebrate communities in the mainstream, tributaries, and oxbow lakes during the normal water and flood periods. The results showed that the traditional alpha taxonomic diversity (TD) varied across habitats, despite minor changes after flood pulse. Alpha phylogenetic diversity (PD) decreased and alpha functional diversity (FD) markedly increased after flooding, with functional traits transiting toward risk avoidance. While all the three facets of beta diversity significantly responded to habitat differences, beta TD and PD shifted in response to flooding. Species turnover prominently increased in beta TD and PD after flood pulse, which contrasted with a weaker response of this process in FD. The explanatory power of significant environmental factors on both alpha and beta diversity was reduced by flooding. Compared with traditional TD, cooperating multi-faceted diversity could better depict the responses of benthic macroinvertebrate communities to flooding. The assessment and conservation of aquatic biodiversity in highland floodplains should take into account the three facets of alpha and beta diversity.

Diversity and distribution patterns of soil macroarthropod communities in the Nianchu River Basin, Tibet, China

IntroductionThe study of how soil fauna interact with soil ecosystems is an important research field. At present, there has been little research on the diversity and distribution patterns of soil macroarthropods and on the relationship between soil fauna and environmental factors in Tibet.MethodsThe data collection for soil macroarthropods and soil samples was conducted using the plum blossom five-point sampling method. Subsequently, the gathered data were meticulously organized and analyzed through a blend of ecological and statistical approaches.ResultsIn total, 2880 soil macroarthropods were captured from 19 plots in the Nianchu River Basin, and the soil macroarthropod Hill numbers was at its lowest in spring. Sea buckthorn forest habitats had the highest Hill numbers. We found that Carabidae, Lycosidae, and Formicidae were always dominant species during seasonal changes in the Nianchu River Basin. Among the four different habitat types studied, Carabidae always appeared across the four studied habitat types and was one of the most significant taxa. The niche range of soil macroarthropods was wetland habitat > farmland habitat > sea buckthorn forest habitat > grassland habitat, and their community within sea buckthorn forest habitats was stable. The niche breadth of soil macroarthropods was the largest in summer, and the community was stable. Soil temperature and soil water content were the most important factors affecting the alpha diversity of soil macroarthropods, while altitude and soil temperature were the most important factors affecting their beta diversity.DiscussionIn summary, the results provide a comprehensive overview of the seasonal and habitat dynamics of soil macroarthropods in the Nianchu River Basin; it is strongly believed that the research carried out in this paper can contribute valuable information toward further research on the soil fauna diversity and ecological functions in this area and provide a strong scientific basis for the protection and sustainable development of the Nianchu River Basin ecosystem.

Cerrado bat community assembly is determined by both present‐day and historical factors

AbstractAimTo investigate the influence of ecological factors, geologic and climatic history on current diversity patterns of bat communities. We predicted that (i) our three different biodiversity dimensions (species richness, functional and phylogenetic diversity) will have a positive relationship with habitat heterogeneity; (ii) variation in phylogenetic diversity will be positively influenced by elevation; (iii) biodiversity dimensions will be influenced by climatic stability, with less diversity in regions with higher climatic instability.LocationNeotropical Savannah (Cerrado).MethodsWe calculated nine metrics: species richness, functional diversity, phylogenetic diversity, mean paired functional distance (MFD) and phylogenetic distances (MPD), richness‐corrected functional diversity (SES‐FD), richness‐corrected phylogenetic diversity (SES‐PD) and richness‐corrected mean functional and phylogenetic distances (SES.MFD and SES.MPD) using distribution records for 111 bat species. Habitat heterogeneity, climatic variables, elevation, floristic and climatic stability were used as independent variables. We used hierarchical Bayesian models to spatialise biodiversity dimensions based on the best predictors.ResultsCerrado habitat heterogeneity is important for phylogenetic diversity and mean functional and paired phylogenetic distances. Precipitation, temperature, elevation, habitat heterogeneity, and climatic stability were the most important predictors of Cerrado bat biodiversity. Species richness is inversely related to climatic instability, which is the best predictor of this metric. There is a decline in species richness in regions where the floristic composition has been more altered during the last 30,000 years, mainly in southern Cerrado.Main ConclusionsPresent‐day and historical factors simultaneously explain the biodiversity dimensions of bat communities in the Cerrado. Habitat heterogeneity is a major driver of phylogenetic diversity of Cerrado bats, and species of closely related lineages share habitats with homogeneous vegetation. Cerrado climatic changes and geologic history influenced the observed diversity metrics (PD and FD) and the ones corrected for species richness (SES‐PD and SES‐FD) in opposite ways. Species richness corrected metrics (SES‐PD and SES‐FD) indicate that species filtered by adaptive traits mainly occupied regions of climatic instability.