Biodiversity and Conservation最新文献

The tight relationship of niche breadth (i.e., environmental tolerance and resource use) with ecomorphological traits and extinction risk makes the study of habitat niche breadth (i.e., habitat heterogeneity; HB) crucial to understanding the species’ ecological niche and macroecological aspects. Additionally, HB has been associated with the species extinction risk (ER) due to human activity. Bats can be ideal for understanding HB’s ecological and conservation relevance due to their diverse diet and other traits, as well as the high number of threatened species. Here, we studied the association between HB, trophic guild (TG), body mass (BoM), and extinction risk (ER) in phyllostomid bat species using a phylogenetic comparative approach. Our results showed that the TG, not BoM, is significantly associated with HB in phyllostomid bats. Omnivorous and sanguinivorous bats have a wider HB than plant-eating and insectivorous bats. Regarding the ER of bats, our results showed that species without risk have wider HB than species at risk. The HB of species without conservation status does not differ from at-risk species, which suggests that at least some species should be considered at risk. In conclusion, our study suggests that diet is a relevant trait that influences the macroecological dynamic of phyllostomid bats due to its relation with HB. Additionally, we provided evidence supporting HB’s use as an ER predictor. Finally, we discussed the necessity of finding alternative and quicker ways to assess the ER of the species.

Plant phenology regulates ecosystem functions at diverse scales but is impacted by micro and macro climatic variations, and climate change. In India, precise estimations of pheno-phase transition dates remain scarce at different spatial and temporal scales, necessitating comprehensive research efforts. This study aims to gather continuous intra-day ground data about vegetation and climate conditions using PhenoCam (optical RGB and IR images) along with meteorological sensors, at Dalma Wildlife Sanctuary (DWS), Jharkhand. To derive phenological metrics, different indices were computed from images captured by PhenoCam sensors and Satellite derived Normalized Difference Vegetation Index (NDVI). Since the PhenoCam covers diverse vegetation species in the frame, the analysis was performed over three specific subset Region of Interests (ROI): Bombax ceiba (Semal) tree, background cluster of vegetation and a sample tree. MODIS NDVI data revealed that most of the area is highly deciduous with major greening in the 1st half of April and senescence during 2nd half of March. The study found that Green Chromatic Coordinate Index (G_CC) and Blue Chromatic Coordinate Index (B_CC) results could reveal greening and senescence phases correctly. The timing of start of leaf flush (SOLF), end of leaf flush (EOLF) and end of leaf maturity (EOLM) estimated based on inflection point method from Pheno-Cam images are: for Semal tree: 5th April, 2nd May, 10th June, 2022; for background vegetation: 15th March, 28th March and 2nd May, 2022; and for sample tree: 15th March, 28th March and 25th April, 2022, respectively. The dates of SOLF differed in 2023 and it occurred twice for Semal and background vegetation: for Semal tree: 20th February and 3rd April 2023, and for background vegetation: 20th January and 8th March, 2023, respectively. The rate of leaf flush and rate of leaf maturity was not similar in different years as the rates were much higher in 2023 than in 2022. The temperature and rainfall during winter and spring played an important role in greening, senescence, and its sustenance. These findings revealed the micro-climatic effect on plant phenology in the Dalma Wildlife Sanctuary, as well as the importance of integrating PhenoCam and satellite data in accurate monitoring of phenological phases.

Effective ecosystem-based management of bottom-contacting fisheries requires understanding of how disturbances from fishing affect seafloor fauna over a wide range of spatial and temporal scales. Spatial predictions of abundance for 67 taxa were developed, using an extensive dataset of faunal abundances collected using a towed camera system and spatially explicit predictor variables including bottom-trawl fishing effort, using a Joint Species Distribution Model (JSDM). The model fit metrics varied by taxon: the mean tenfold cross-validated AUC score was 0.70 ± 0.1 (standard deviation) for presence–absence and an R² of 0.11 ± 0.1 (standard deviation) for abundance models. Spatial predictions of probability of occurrence and abundance (individuals per km²) varied by taxon, but there were key areas of overlap, with highest predicted taxon richness in areas of the continental shelf break and slope. The resulting joint predictions represent significant advances on previous predictions because they are of abundance, allow the exploration of co-occurrence patterns and provide credible estimates of taxon richness (including for rare species that are often not included in more commonly used single-species distribution modelling). Habitat-forming taxa considered to be Vulnerable Marine Ecosystem (VME) indicators (those taxa that are physically or functionally fragile to anthropogenic impacts) were identified in the dataset. Spatial estimates of likely VME distribution (as well as associated estimates of uncertainty) were predicted for the study area. Identifying areas most likely to represent a VME (rather than simply VME indicator taxa) provides much needed quantitative estimates of vulnerable habitats, and facilitates an evidence-based approach to managing potential impacts of bottom-trawling.

Human–elephant conflict (HEC) is a serious social–ecological problem in Sri Lanka’s elephant range regions, as between 200 and 400 elephants have been killed annually over the last years, and more than 1200 people have died from the consequences of elephant encounters within a decade. Crop foraging causes economic damage to farming households. The study aims to understand factors driving vulnerability to HEC among the population. Employing a cross-communal multi-item large-N field survey (N = 651), authors were able to describe living conditions and perceptions of Sri Lankan villagers affected by HEC. By running a multiple regression analysis with correlated variables, the study is able to correlate independent variables to vulnerability, namely socio-economic conditions, environmental change and land-use, and awareness. Furthermore, a vulnerability map has been created, identifying Puttalam, Anuradhapura, Kurunegala, Matale, and Polonnaruwa districts as conflict hotspots. Private electric fences as a widespread protection measure were found to have unintended negative side-effects to non-protected households. The findings suggest the urgent need to upscale public policies mitigating the consequences of HEC on affected populations by reducing overall vulnerability to environmental hazards, including human–wildlife conflict.

With the increase in deforestation associated with the need to reconcile conservation and food production, agricultural mosaics are of great importance in maintaining biodiversity. This study aimed to compare the shade-tolerant plants diversity partition pattern and the conservation value (CV) presented by land-use types found in three vertical strata (upper, middle, and lower) of six agricultural mosaics in the eastern Amazon. Additionally, we hypothesized that agricultural mosaics with lower forest cover, with lower heterogeneity of land-uses, and drier areas have lower shade-tolerant plants diversity, and CV of land-use types. Plant surveys were carried out in family farming mosaics with fixed plots; a matrix of species abundance per plot was set up for each mosaic and stratum. Additive partition and absolute contribution analyze were applied to each matrix; and CV of the land-uses for gamma richness was calculated. Factors were tested using generalized linear models and simple linear regression. Our results indicate that there is a diversity pattern that is repeated in the strata and agricultural mosaics. Beta diversity, especially among land-use types, is the one that most contributes to the diversity. Habitat heterogeneity is very important for the conservation of shade-tolerant species, but it is not the number of different land-use types but what these land-uses are. Land-uses with low CV do not add diversity to the mosaic. Consequently, the quality of the environmental matrix is very important. This information will be useful in providing baseline data on the management of agricultural mosaics in the eastern Amazon.

In the Brazilian Eastern Amazon, an area with high biological endemism, oil palm plantations rapidly expand, presenting ongoing challenges to prevent deforestation and biodiversity loss. This study was developed in the Belém Endemism Area and assessed the impacts of oil palm expansion on biological and social aspects. The biological impact analysis compared biodiversity in seven taxonomic groups between forests and oil palm plantations. It revealed a decline in diversity for aquatic insects (Hemiptera), amphibians, reptiles, birds, and plants, while fish and Odonata insect diversity increased in plantations. On the social front, local communities’ perceptions of socioeconomic and environmental changes due to oil palm expansion were examined. Smallholders and hired workers had a lesser negative perceptions than people with no relation with the oil palm value chain, regarding socioeconomic factors (e.g., contributions to the local economy and job opportunities), as well as environmental aspects (e.g., water availability and air and water quality). Our study highlights biological and social factors in the context of oil palm expansion that should be considered to ensure more sustainable development in this ecologically unique and threatened region. Certified companies are encouraged to achieve zero deforestation rates and implement social programs that integrate all local communities into the value chain, aiming for coexistence between oil palm cultivation and biological conservation in the Amazon.

Small Shallow Lakes and ponds (SSLs) provide numerous ecosystem services and harbour unique biodiversity. They are very vulnerable to human disturbances and play a central role in ecosystem functioning. In this study, we aimed to disentangle the role of environmental variables in the composition and richness of invertebrate communities using datasets collected from 143 French SSLs with minimal impact from human activities. The SSLs were sampled across four climatic ecoregions, encompassing various geologies and elevations. A hierarchical classification revealed a clear separation into two groups: (1) highland waterbodies and (2) lowland waterbodies. The main environmental variables identified by the db-RDA were elevation associated with climate, and the presence of fish, along with interrelated variables such as SSLs morphology. Generalised additive models GAMs that combined diversity and composition indices or taxonomic richness with determinant environmental variables demonstrated that (1) elevation, mesohabitat complexity and the presence of exotic crayfish strongly influenced the structure, richness, and composition of macroinvertebrate communities, and (2) the presence of fish had a significant impact only on community composition (e.g., reducing the relative richness of typical pond-swimmer taxa). Furthermore, even though connectivity with other waterbodies influenced the macroinvertebrate communities, its impact appeared to be less significant than elevation, climate, and local variables such as the presence of predators (fish or crayfish).

Forest fragmentation is one of the main drivers of global biodiversity loss leading to the isolation of wildlife populations. This study focuses on understanding the role of restoration corridors as a strategy promoting resilience and viability of mammal and bird populations in a fragmented landscape in Colombia. We installed 98 camera-trap stations − 8497 camera-trap days - in four different land cover categories: (1) forest fragments, (2) natural corridors, (3) stablished corridors and (4) pastures. We evaluated if restoration corridors do promote connectivity for large vertebrates and recover species richness and functional diversity lost in anthropogenically transformed pastures. We used indices of taxonomic and functional diversity and a non-metric multidimensional scaling to evaluate the influence of land cover over mammal and bird communities. Both, species richness and functional diversity have higher values in forests, followed by natural corridors and corridors and lower values in open pastures. Differences in species composition were greater between forests and pastures, and species composition of restoration corridors begins to resemble that of riparian forests and forest fragments. Our results provide initial evidence on the role of restoration corridors as an efficient strategy aimed to recover biodiversity and functional diversity in pervasively fragmented landscapes.

Across Africa, space for conservation is sometimes limited to formally protected areas that have become progressively more isolated. There is a need for targeted conservation initiatives such as the demarcation of landscape connections, defined as areas that encompass environmental variables that promote the natural movement of individuals between populations, which can facilitate gene flow. Landscape connections can mitigate genetic isolation, genetic drift, and inbreeding, which can occur in isolated populations in protected areas. Promoting gene flow can reduce the risk of extirpation often associated with isolated populations. Here we develop and test models for identifying landscape connections among African savannah elephant (Loxodonta africana) populations by combining habitat suitability modeling with gene flow estimates across a large region including seven countries. We find a pronounced non-linear response to unsuitable habitat, consistent with previous studies showing that non-transformed habitat models are poor predictors of gene flow. We generated a landscape connections map that considers both suitable habitats based on telemetry occurrence data and gene flow estimated as the inverse of individual genetic distance, delineating areas that are important for maintaining elephant population connectivity. Our approach represents a novel framework for developing spatially and genetically informed conservation strategies for elephants and many other taxa distributed across heterogeneous and fragmented landscapes.

Graphical abstract

Human impacts on ecosystems often transcend ecosystem boundaries and environmental realms, complicating ecosystem assessment, conservation, and management. Whether and how different impacts affect ecosystems in distinct but adjacent domains remains untested in many settings, and is rarely tested concurrently at the same spatial scales. In this study, we quantified the effects of coastal urbanisation on the structure of terrestrial coastal vertebrate assemblages (including birds, reptiles and mammals using baited trail cameras) and marine surf zone fish assemblages (using baited underwater videography) at 100 sites along 50 km of beach in eastern Australia. Sites occurred along a gradient of intensities of urban land conversion in the hind dunes. While the effects of urbanisation on the species sampled were pervasive across both ecosystems, the area of urbanised land mattered more for the coastal vertebrates observed, while proximity to urbanised land was more important for the surf zone fish observed. Here, fewer individuals and species of coastal vertebrates were found at sites with a greater extent of urbanised land within 5 km. Conversely, fish assemblages were more diverse in the surf zones abutting urban areas and more abundant at sites approximately 150 m from urbanised land. The spatial properties of these landscapes, including proximity to headlands for coastal vertebrates and reefs for fish, modified the effects of urbanisation. Our findings suggest that urbanisation can have ecologically nuanced effects that are detectable across the land-sea boundary, and stress the importance of landscape context when assessing and conserving animal assemblages in and around coastal cities.