Aim: Biodiversity monitoring and conservation are extremely complex, and surrogate taxa may represent proxies to test methods and solutions. However, cross-taxon correlations in species diversity ...(i.e., cross-taxon congruence) may vary widely with spatial scale. Our goal is to assess how cross-taxon congruence varies with spatial scale in European temperate forests. We expect that congruence in species diversity increases when shifting from fine to coarse spatial scales. with differences between species richness and composition, and across pairs of taxonomic groups. Location: European temperate forests. Time period: Present. Major taxa studied: Vascular plants, bryophytes, birds, epiphytic lichens, saproxylic beetles and wood-inhabiting fungi. Methods: We used field data (354 plots across 23 sites) encompassing Italy, France and Hungary, with species information for six taxonomic groups. We accounted separately for spatial grain (the size of elementary sampling unit) and extent (the geographical area included in the survey) and evaluated the relationships within all the possible pairs of taxa. Results: Although no pair of taxa had its species richness consistently correlated across scales, we found no changes in the direction of correlations when analysing species composition. However, when increasing grain and extent, we did find a general increase in the magnitude of correlations in species composition and partial changes in significance, with plants having the highest number of significant correlations. Main conclusions: Species richness congruence among taxa is strongly scale dependent owing to differences in the relative contribution of large- and small-scale processes across taxa. Cross-taxon congruence in species composition is scale dependent only for its magnitude, because life-history traits of individual species make responses to environmental factors similar across scales. Forest monitoring should consider multi-taxon sampling and limit the use of surrogates at specific spatial scales, especially for species richness. Sampling plant species composition in scattered plots across different sites may effectively summarize the whole community composition.
While provision of in-stream habitat complexity remains common practice in efforts to restore streams, the evidence of positive effects on in-stream communities is inconsistent. In streams of urban ...catchments, where both reach-scale habitat manipulation and catchment-scale actions to ameliorate the disturbance regime of urban stormwater runoff are common management responses, clearer understanding of the effects of habitat complexity under different degrees of urban impact are needed. We experimentally assessed the effect of increased surface complexity in wood, the dominant hard substrate in our 18 study reaches on 14 small streams, on in-stream macroinvertebrate assemblages across a range of urban impact. Increased surface complexity increased abundance of most taxa, but this effect was less pronounced in urban streams, partly because of the reduced species pool tolerant of urban stormwater impacts, and partly because of a lesser response of some species to increased complexity in more urban streams. Collectively these taxon-specific effects resulted in small, uncertain increases in taxon richness with increased complexity in rural streams, and no change in richness of the less diverse assemblages of urban streams. Increased abundances suggest increased availability of refugia or resources with increased surface complexity, while the reduced effect of complexity in urban streams suggests that any refuge or resource provided by greater surface complexity is less effective in more disturbed environments receiving urban stormwater runoff. The reduced abundance of sensitive taxa in more urban streams, and the resultant reduced richness, confirms that urban stormwater runoff acts as a strong environmental filter, limiting the species pool available for community assembly. Restoration of habitat complexity in streams without catchment-scale drivers of degradation is likely to have positive benefits to in-stream biotic assemblages, but the efficacy of such approaches in catchments subject to urban stormwater runoff will be greatly diminished. In such cases, restoration activities should first be aimed at controlling the larger-scale problem.
•Forest management strongly affected the presence of specialist species.•Accounting only for species richness may provide biased information for conservation.•Functional approach is promising for ...better-informed conservation planning.•Lists of conservation-relevant species are effective for understudied groups.•A multi-taxon framework is needed for guiding conservation action.
We investigated the consistency between richness and trait-based diversity metrics in capturing the effects of management-related habitat factors on biodiversity. The choice of biodiversity metrics can substantially affect the evaluation of conservation tools. However, the relative sensitivity of different metrics is not well investigated, especially in a multi-taxon framework.
European beech forests in Denmark.
We studied 20 beech stands comprising four management types (from intensively managed to long unmanaged stands). We analyzed how management-related environmental variables were reflected in the measure of: (i) species richness, (ii) number of conservation-relevant species (red-listed species and old-growth forest indicators) and (iii) functional diversity targeting five organism groups with different habitat requirements, i.e. vascular plants, epiphytic lichens and bryophytes, saproxylic fungi and breeding birds.
Plain species richness at stand level was generally misleading, as it did not capture changes in the number of conservation relevant species with changes in management-related environmental variables. The interpretation of functional responses was most informative for the better known vascular plants, while responses were more fragmented for the other organism groups. Overall, however, functional responses were consistent with a loss of specialization and progressive simplification of species assemblages from long-unmanaged to intensively managed stands.
Our findings suggest that the occurrence of conservation-relevant species is a sound and relevant metric for planning and evaluating conservation actions, especially for less studied organism groups (e.g., saproxylic fungi and epiphytes). The functional approach is promising, but presupposes the availability of databases of relevant traits.
Human activities in the Anthropocene have led to the conversion of a significant area of the Earth's surface to agroecosystems, including tree plantations such as eucalyptus. Brazil, as the largest ...producer of eucalyptus timber, faces the challenge of preserving its rich biodiversity, particularly in the Atlantic Forest biome, which is one of the world's most threatened and diverse. This study aimed to assess the impact of eucalyptus plantation on soil invertebrate communities compared to that of native forest remnants. We sampled ants, beetles, springtails, and spiders as model groups to evaluate the alpha diversity and composition of soil invertebrates in these forests. We also examined trophic interactions between springtails and their potential natural enemies (spiders, ants, and beetles) in both environments. Our results revealed that the abundance and richness of ants and beetles were higher in native forests than in eucalyptus plantations, whereas springtails exhibited a negative response to eucalyptus plantation in terms of abundance, and spiders showed higher richness in eucalyptus plantations. Furthermore, the composition of soil invertebrate communities, with the exception of springtails, was significantly different between eucalyptus plantations and native forests.The correlations between the abundance of springtails and their potential predators (spiders and beetles) were significantly reduced in eucalyptus plantations compared with native forests. Our findings highlight the negative impact of eucalyptus plantation on soil invertebrate diversity and community composition, potentially disrupting predator-prey relationships and emphasizing the importance of preserving native forests to safeguard invertebrate biodiversity and ecological processes.
•We aimed the impact of eucalyptus monoculture on soil invertebrate compared to native forest.•Invertebrates diversity were greater in the forest than eucalyptus, with the exception of spiders.•Composition invertebrate differ between environments, with the exception of springtails.•Abundance correlations of springtails and their predators were reduced in eucalyptus.
Land-use change has caused degradation, loss and fragmentation of semi-natural habitats, especially in grassland ecosystems. Today, the remaining habitats are often situated in a matrix of ...intensively used agricultural land and are therefore more or less isolated from each other. Connectivity, area and quality of habitat patches have been identified as the most important drivers for the persistence of grassland specialists living in metapopulations. However, the relative importance of these factors is still under debate. We used a large-scale, multi-taxon approach to obtain a general pattern which would facilitate conservationists to promote many, instead of one, species. We studied the patch occupancy of 13 grassland specialists belonging to three different insect orders within a Central European landscape with 89 fragments of calcareous grasslands. To disentangle the relative importance of the three metapopulation parameters, generalized linear models (GLM) and variation-partitioning techniques were used. Our study revealed that habitat quality was the most important factor determining the occurrence of specialized species, followed by habitat area. In comparison to habitat connectivity, the variance explained by habitat quality was significantly higher across the studied species. Nevertheless, the persistence of at least six model organisms depended on the degree of habitat connectivity. We conclude that maintaining a high habitat quality on large patches should be the first choice for the conservation of habitat specialist insects in fragmented landscapes. As a secondary measure, conservationists should concentrate on the restoration of relict sites. This increases not only the habitat area, but also contributes to better habitat connectivity.
•Large-scale, multi-taxon metapopulation study in fragmented landscapes•First study that quantifies the relative importance of the key factors determining patch occupancy of specialist insects•Variation-partition techniques were used to disentangle the effects of different metapopulation parameters•Habitat quality and area were more important for specialists than connectivity•Large patches with high quality should be obtained highest conservation priority
Aims: Climate change can substantially alter ecological communities. However, we hypothesized that, even if novel communities emerge, those communities may not be novel in terms of functional ...composition. To infer the processes associated with rising temperatures, we evaluated elevational taxonomic/functional turnover of plant and invertebrate communities. Because climate change interacts synergistically with other environmental factors, and therefore is not the sole driver of change in ecological communities, we also considered how the taxonomic/functional composition of the communities would be affected by mammalian overgrazing/browsing, which has become prominent in the study region. Location: Shiretoko National Park, Shiretoko Peninsular, Hokkaido, Japan. Methods: We investigated the diversity of eight groups of organisms (taxa) in forests of northern Japan, and calculated the distance decay of taxonomic/functional similarity (Sørensen's β-diversity) along an elevational gradient. A null model was used to separate functional turnover from taxonomic turnover. We then simulated ow taxonomic/functional turnover along the gradient would be changed after non-random loss of species sensitive to mammalian herbivory. Results: We found that each group showed elevational decay in taxonomic similarity. Along an elevational gradient, species groups structured by stronger dispersal limitation showed faster species turnover. This suggested differences in the process of climate-induced species reassembly among the groups. We also found that elevational turnover of communities based on functional traits tended to be lower than that based on taxonomic identity for the majority of the groups, supporting our hypothesis of functional redundancy across the elevational gradient. We thus speculated that climate-induced emergence of taxonomically novel communities may have limited influence on critical ecosystem processes supported by functional diversity. Furthermore, while random species loss did not change functional turnover, non-random loss of species attributable to mammalian herbivory substantially accelerated elevational functional turnover of the taxa. This suggested a possible loss of the functional redundancy of communities. Main conclusions: Future communities may be novel not simply because climates are changing at unprecedented rates but also because of the synergetic influences of other environmental changes. Thus ecological processes may be more seriously affected in the future than is generally anticipated based onexisting climate-change scenarios, with possible consequences for ecosystem functioning.
Species diversity is the variable most commonly studied in recent ecological research. Ecological processes, however, are driven by individuals and affected by their abundances. Understanding the ...variation in animal abundances along climatic gradients is important for predicting changes in ecosystem processes under global warming. High abundances make arthropods, despite their small body sizes, important actors in food webs, yet abundance distributions of major arthropod taxa along climatic gradients remain poorly documented. We sampled arthropod assemblages in disturbed and undisturbed vegetation types along an elevational gradient of 860–4550 m asl on the southern slopes of Mt. Kilimanjaro, Tanzania. In our analysis, we focused on 13 taxa of arthropods that represented three major functional groups: predators, herbivores, and decomposers. Abundance patterns were unimodal for most of the taxa and functional groups, including decomposer arthropods, and most of them peaked at low elevations in lower montane forest. When we assigned beetles to functional groups, however, decomposer beetle abundances declined almost linearly, and abundances of predator beetles (ca. 2400 m asl) and herbivore beetles (ca. 3000 m asl, undisturbed vegetation) peaked at higher elevations and exhibited unimodal patterns. Temperature, not primary productivity, was the best predictor of abundance for most of the taxa and groups. Disturbance was only of minor importance. Our results revealed different trends in the response of arthropod abundance along the elevational gradient that depended on the level of taxonomic and functional resolution. This highlights the need for more comparisons of different taxa along the same climatic gradients.
The Humboldt’s enigma has continued for many centuries, A multitude of studies have delved into various potential reasons for this richness—from topography and climate to community succession—yet a ...singular, all-encompassing theory for species richness across multiple taxa in mountain ecosystems remains elusive. In this research, we explored the causes of species richness in mountain multiple-taxa in terms of spatial attributes of protected areas, human disturbance and environmental factors. Initiating our study, we compiled a comprehensive database of all national nature reserves (NNRs) situated in the karst regions of Guizhou province. This was achieved through an extensive multidisciplinary field survey in recent years, resulting in a collection of 40,570 species records. Subsequently, we discerned a complex interplay between species richness, spatial attributes, human disturbance, and environmental factors, which collectively account for over 80 % of the observed variations in mountain biodiversity. Our findings revealed several intricate relationships: Shape index and fragmentation positively influenced the richness of insect, animal, and seed plant species. Conversely, anthropogenic alterations and nighttime light negatively impacted the diversity of amphibians, reptiles, and mammals. Interestingly, we discovered a significant positive association between the richness of fungi, mosses, and ferns and the variables of soil texture and soil water, demonstrating the importance of soils in karst for maintaining biodiversity. To conclude, we evaluated conservation strategies in mountainous regions. It is imperative that the spatial configuration of protected areas be refined to alleviate the detrimental effects of human disturbance. Furthermore, conservation efforts should be customized to the unique climatic and geographic conditions found locally.
Monitoring programs aimed at assessing ecological restoration have often relied on the response of a single taxon owing to the difficulty of sampling multiple taxonomic groups simultaneously. Using ...passive acoustic monitoring, we examined the impacts of ecological restoration on all vocalizing fauna simultaneously as well as a single indicator taxon, birds. In our study, acoustic recorders were programmed to collect data along a gradient of forest regeneration consisting of actively restored (AR), naturally regenerating (NR), and mature benchmark (BM) sites in a tropical biodiversity hotspot, the Western Ghats of southern India. For all vocalizing fauna, we calculated acoustic space use, a measure that reflects the amount and pattern of sounds within each frequency bin for a given time period. AR and NR sites were not significantly different from each other, and visual examination of the acoustic space showed a lack of sounds between 12 kHz to 24 kHz for AR and NR sites, suggesting limited insect activity. When we considered the response of birds alone (from manually annotated acoustic data), we found significant differences in the proportion of detections of rainforest bird species compared to open-country bird species across all treatment types, with the highest proportion reported in BM sites (mean ± SD: 0.97 ± 0.04), followed by AR sites (0.81 ± 0.12) and NR sites (0.71 ± 0.17). Considering the varied response of different taxa to habitat recovery over two decades, we highlight the need to take a multi-taxon approach while assessing restoration programs. We show that it is now possible to do so in tropical forests using passive acoustic monitoring.
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•Acoustic data can be used to assess the multi-faunal response to ecological restoration.•Rainforest birds are returning to actively restored sites.•Limited insect vocalizations were detected in actively restored and naturally regenerating sites.
Reliable estimates of wildlife mortality due to wildlife-vehicle collisions are key to understanding its impact on wildlife populations and developing strategies to prevent or reduce collisions. ...Standardised approaches for monitoring roadkill are needed to derive robust and unbiased estimates of mortality that are comparable across different study systems and ecological contexts. When designing surveys, there is a trade-off between survey frequency (and hence logistical effort and financial cost) and carcass detection. In this regard, carcass persistence (the period a carcass remains detectable before being removed by decomposition or scavengers) is important; the longer a carcass persists, the greater the likelihood it will be detected with lower survey effort by conducting more infrequent surveys. Using multi-taxon carcass data collected over a month of repeated driven surveys, combined with five covariates (species functional group, body weight, carcass position on road, carcass condition either flattened or not after impact, and rainfall prior to each survey), we explored the drivers of carcass persistence with the overall aim of providing information to optimise the design of carcass surveys along linear infrastructure. Our methodological approach included a survival analysis to determine carcass persistence, linear regressions to test the effect of covariates, a subsampling analysis (using field data and a simulation exercise) to assess how the proportion of carcasses detected changes according to survey frequency, and an analysis to compare the costs of surveys based on study duration, transect length and survey frequency. Mean overall carcass persistence was 2.7 days and was significantly correlated with position on road and within-functional group body weight. There was no evidence for a significant effect of rainfall, while the effect of carcass condition was weakly non-significant. The proportion of carcasses detected decreased sharply when survey intervals were longer than three days. However, we showed that survey costs can be reduced by up to 80% by conducting non-daily surveys. Expanding on the call for a standardised methodology for roadkill surveys, we propose that carcass persistence be explicitly considered during survey design. By carefully considering the objectives of the survey and characteristics of the focal taxa, researchers can substantially reduce logistical costs. In addition, we developed an R Shiny web app that can be used by practitioners to compare survey costs across a variety of survey characteristics. This web app will allow practitioners to easily assess the trade-off between carcass detection and logistical effort.
•In roadkill studies there is a trade-off between survey cost and the number of carcasses detected.•Carcass persistence can be used to inform optimal roadkill survey design.•Survey costs can be reduced by 80% by conducting non-daily surveys based on different level of carcass persistence.•We developed an online R Shiny web app to compare costs across different survey scenarios.
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