Search

Wildlife trade is a major driver of biodiversity loss, yet whilst the impacts of trade in some species are relatively well-known, some taxa, such as many invertebrates are often overlooked. Here we explore global patterns of trade in the arachnids, and detected 1,264 species from 66 families and 371 genera in trade. Trade in these groups exceeds millions of individuals, with 67% coming directly from the wild, and up to 99% of individuals in some genera. For popular taxa, such as tarantulas up to 50% are in trade, including 25% of species described since 2000. CITES only covers 30 (2%) of the species potentially traded. We mapped the percentage and number of species native to each country in trade. To enable sustainable trade, better data on species distributions and better conservation status assessments are needed. The disparity between trade data sources highlights the need to expand monitoring if impacts on wild populations are to be accurately gauged and the impacts of trade minimised. Trade in arachnids includes millions of individuals and over 1264 species, with over 70% of individuals coming from the wild. [ABSTRACT FROM AUTHOR]

Understanding the causes behind species richness and endemicity is fundamental to explain biodiversity and assist conservation management, especially in biodiversity hotspots like the Mediterranean Basin. Here we investigate the patterns in Iberian forest spider communities and the processes behind their assembly, by testing hypotheses about the effects of climate and habitat on species richness, endemicity and structure of communities at different spatial scales, and about how microhabitat and dispersal affect the level of endemicity of species. We studied 16 spider communities in Iberian Quercus forests from different climatic zones, applying a standardised sampling protocol. We examined the contribution of habitat, climate, and geography to the differences in the composition of spider communities across spatial scales using distance-based redundancy analysis models (dbRDA) and principal coordinates of neighbour matrices (PCNM). We assessed the effects of the same variables on the endemicity of communities (measured by a weighted index), and tested the correlation between the microhabitat and the ballooning frequency (obtained from bibliography), and the endemicity of species through generalised linear models. Spider communities formed two groups—one southern and one northern—based on similarity in species composition. Precipitation and temperature were inversely related with the number of species while geography and forest type explained the compositional similarities between communities at different spatial scales. Endemicity of communities increased with temperature and decreased with precipitation, whereas species endemicity decreased with ballooning frequency. Our findings illustrate how niche-related processes may drive spider diversity while dispersal determines species distribution and identity and, ultimately, community composition. From a conservation viewpoint, when maximising species richness is incompatible with prioritising endemicity, the criteria to follow may depend on the geographic scale at which decisions are made. [ABSTRACT FROM AUTHOR]

Oceanic islands host a high proportion of the world's endemic species. Many such species are at risk of extinction owing to habitat degradation and loss, biological invasions and other threats, but little is known about the effects of climate change on island native biodiversity. The Azorean archipelago provides a unique opportunity to study species-climate-change relationships. We used ensemble forecasting to evaluate the current and future distribution of well-studied endemic and native bryophytes (19 species), endemic vascular plants (59 species) and endemic arthropods (128 species), for two of the largest Azorean Islands, Terceira and São Miguel. Using a Regional Climate Model (CIELO), and assuming the extreme scenario RCP8.5, we examined changes in the potential distributions of the species and possible loss of climate space for them. Models projected that 23 species (11 %) could lose all adequate climate on either one or both islands. Five additional species were projected to lose ≥90 % of climate space. In total, 90 % of the species were projected to lose climate space: 79 % of bryophytes, 93 % of vascular plants and 91 % of arthropods. We also found for vascular plants and arthropods a tendency for upward shift in altitude in their suitable climate space, while for bryophytes the shift was towards the coastal areas. Our results have profound implications for future conservation priorities on islands, such as for the redrawing of conservation borders of current protected areas. [ABSTRACT FROM AUTHOR]

The Iberian Peninsula is recognized for its high levels of species richness, rarity and endemicity. Our main aim was to study biogeographic patterns of spiders in coastal dunes along a gradient of mediterraneity. Distance-decay of similarity, nestedness and co-occurrence metrics were used to explore spider' distribution patterns. A similarity analysis was performed in order to obtain a hierarchical classification of sites. Indicator species analysis was conducted to identify indicator species for the various clustering levels of the site typology. The differentiation among assemblages was further explored by non-metric multidimensional scaling (NMDS) and analysis of similarities (ANOSIM). Assemblages' similarity among sites decreased with climatic/geographic distance. The observed values of nestedness metrics (T and NODF) were not significant, while the co-occurrence metrics (C-score and Checkerboard units) were higher than expected by chance. Cluster analysis showed that spider' assemblages were structured along a gradient from North to South, forming four geographically distinct clusters. ANOSIM tests and NMDS supported the biogeographic patterns identified by cluster analysis. Several indicator species were found for the different levels of the hierarchic site typology. Spider assemblages revealed a high degree of biogeographical structure along the Atlantic coast of the Iberian Peninsula. The coast is a 'biogeographic crossroad', encompassing faunistic elements of different origins. The hierarchic typology of sites is generally consistent with the major biogeographic regions and the thermoclimatic belts recognized for the region. Our results indicate that the climatic gradient and historic factors played a key role in the current spiders' biogeographic patterns. [ABSTRACT FROM AUTHOR]