Determinants of beta diversity of spiders in coastal dunes along a gradient of mediterraneity (original) (raw)
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Acta Botanica Brasilica
Patterns of species diversity are essential to understand community structure. We aimed to determine species diversity and patterns of beta diversity in different spatial scales. We sampled three thousand individuals between the coordinates 22°10'S to 22°16'S and 47°47'W to 48°00'W to assess species diversity in three spatial scales (maximum distances of 80 m, 1,400 m, and 12,000 m), using the point-centered-quarter method. We partitioned gamma diversity into alpha and beta components. Beta diversity was partitioned into dissimilarities produced by spatial species turnover and nestedness. The contribution of beta diversity to gamma diversity was greater than that of alpha diversity in all scales, although the patterns of species diversity were similar for the evaluated scales, and was similar to that described for larger spatial scales. The sampled fragments presented means of 15 exclusive species and 47.5 species per fragment, and dissimilarities [β(SØR)=0.7] almost completely explained (94 %) by spatial species turnover. The results indicate that the remnant fragments are residual patches of an originally heterogeneous vegetation. The fragmentation processes could have progressed differently in each portion of the original vegetation, producing the current heterogeneous vegetation. Thus, there is a potential of high local species extinctions if the remnant fragments are deforested.
Biodiversity and Conservation, 2019
To understand patterns of alpha, beta and gamma diversities in fragmented landscapes we need to explore the three scale components in relation to potential drivers in a scaledependent manner. Often, the drivers themselves can be partitioned to alpha, beta and gamma diversities. Thus, one can hypothesize that the scale-components of species diversity and drivers' diversity match, i.e., that species alpha diversity is mainly explained by drivers' alpha diversity, beta by beta and gamma by gamma. Here, we explore this 'scalematching' hypothesis for spiders in two fragmented agricultural landscapes. In each landscape, we sampled spiders and their potential prey in 12 patches. Then, we sub-sampled pseudo-landscapes in which we calculated spider alpha, beta and gamma diversities using multiplicative diversity-partitioning. Next, we used variance partitioning analysis to explore the relative contribution of eleven explanatory variables from five thematic groups (sampling intensity, area, connectivity, habitat diversity and prey diversity), while further partitioning the habitat and prey diversities to their corresponding alpha, beta and gamma diversities. We found considerable evidence for scale-matching, with spiders' alpha and beta diversities explained mostly by the corresponding alpha and beta diversities (respectively) of prey and/or habitat. We further found a strong effect of connectivity on spider beta diversity, but not on alpha and gamma diversities. For spiders gamma diversity, a cross-scale effect was observed. Our results suggest that multiple drivers from multiple scales interact in structuring patterns of spider alpha, beta and gamma diversities in agroecosystems, yet the strongest effects are of those drivers that match in scale.
Distinguishing the roles of dispersal in diversity maintenance and in diversity limitation
Folia Geobotanica, 2005
Considerable recent research effort has gone into studying how dispersal might affect the diversity of local communities. While this general topic has received attention from theoretical and empirical ecologists alike, the research focus has differed between the two groups; theoretical ecologists have explored the role of dispersal in the maintenance of diversity within local communities, whereas empirical ecologists have sought to quantify the role of dispersal in limiting local diversity.
The spatial scaling of beta diversity
Global Ecology and Biogeography, 2013
Beta diversity is an important concept used to describe turnover in species composition across a wide range of spatial and temporal scales, and it underpins much of conservation theory and practice. Although substantial progress has been made in the mathematical and terminological treatment of different measures of beta diversity, there has been little conceptual synthesis of potential scale-dependence of beta diversity with increasing spatial grain and geographic extent of sampling. Here, we evaluate different conceptual approaches to the spatial scaling of beta diversity, interpreted from 'fixed' and 'varying' perspectives of spatial grain and extent. We argue that a 'sliding window' perspective, in which spatial grain and extent covary, is an informative way to conceptualise community differentiation across scales. This concept more realistically reflects the varying empirical approaches that researchers adopt in field sampling and the varying scales of landscape perception by different organisms. Scale-dependence in beta diversity has broad implications for emerging fields in ecology and biogeography, such as the integration of fineresolution eco-genomic data with large-scale macroecological studies, as well as for guiding appropriate management responses to threats to biodiversity operating at different spatial scales.
Mechanisms of community assembly explaining beta‐diversity patterns across biogeographic regions
2021
This is an open access article under the terms of the Creative Commons AttributionNonCommercialNoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is noncommercial and no modifications or adaptations are made. © 2021 The Authors. Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Associationfor Vegetation Science. 1Department of Ecology and Natural Resource Management, Norwegian University of Life Sciences (NMBU), Ås, Norway 2Center for Conservation and Sustainable Development, Missouri Botanical Garden, St. Louis, Missouri, USA 3Departamento de Biología, Área de Botánica, Universidad Autónoma de Madrid, Madrid, Spain 4Centro de Investigación en Biodiversidad y Cambio Global (CIBCUAM), Universidad Autónoma de Madrid, Madrid, Spain 5Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA 6Tyson Research Center, Washington University in St. Louis, ...
Arthropod beta-diversity is spatially and temporally structured by latitude
Research Square (Research Square), 2022
Aim: Global gradients in species biodiversity may or may not be associated with greater species replacement closer to the equator. Yet, empirical validation of these patterns has so far focused on less diverse taxa, with comparable assessments of mega-diverse groups historically constrained by the taxonomic impediment. Location: Global Time period: 2010-2017 Major taxa studied: Terrestrial arthropods Methods: Here we assess the temporal and spatial dynamics of arthropod communities using a beta-diversity framework, drawing on samples across 129 globally distributed monitoring sites. Overall, we encountered more than 150,000 unique barcode index numbers (BINs) (i.e. species proxies). We assessed between site differences in community diversity using betadiversity and the partitioned beta-diversity components of species replacement (i.e. turnover) and richness difference (i.e. a measure of nestedness). Results: We show that global differences in community compositional change are linked to latitudinal, spatial, and temporal gradients. General global beta-diversity trends remained consistent across biogeographic regions, with beta-diversity (dissimilarity) increasing with decreasing latitude, greater spatial distance and greater temporal distance. By contrast, species replacement and richness difference patterns varied across biogeographic regions, suggesting different underlying processes are shaping regional biodiversity patterns. Latitudinal effects on species replacement or richness difference were significant for 3 out of 5 regions. Comparably we found significant spatial distance relationships with species replacement or richness difference for 3 out of 5 regions. Temporal distance was significantly associated with species replacement or richness difference for all 5 regions. Main conclusion: The general expectations of the latitudinal diversity gradient (LDG) are supported using a large, extensive global sampling effort. Our findings generally support the global LDG expectations, however, partitioned assessment of beta-diversity indicates the underlying processes driving the general global pattern, here species replacement and richness 2 difference, may be regionally linked to differences in seasonality effects or variation in spatial distribution of environmental factors.
Effect of landscape structure on species diversity
The effects of habitat fragmentation and their implications for biodiversity is a central issue in conservation biology which still lacks an overall comprehension. There is not yet a clear consensus on how to quantify fragmentation even though it is quite common to couple the effects of habitat loss with habitat fragmentation on biodiversity. Here we address the spatial patterns of species distribution in fragmented landscapes, assuming a neutral community model. To build up the fragmented landscapes, we employ the fractional Brownian motion approach, which in turn permits us to tune the amount of habitat loss and degree of clumping of the landscape independently. The coupling between the neutral community model, here simulated by means of the coalescent method, and fractal neutral landscape models enables us to address how the species-area relationship changes as the spatial patterns of a landscape is varied. The species-area relationship is one of the most fundamental laws in ecology, considered as a central tool in conservation biology, and is used to predict species loss following habitat disturbances. Our simulation results indicate that the level of clumping has a major role in shaping the species-area relationship. For instance, more compact landscapes are more sensitive to the effects of habitat loss and speciation rate. Besides, the level of clumping determines the existence and extension of the power-law regime which is expected to hold at intermediate scales. The distributions of species abundance are strongly influenced by the degree of fragmentation. We also show that the first and second commonest species have approximately self-similar spatial distributions across scales, with the fractal dimensions of the support of the first and second commonest species being very robust to changes in the spatial patterns of the landscape. Citation: Campos PRA, Rosas A, de Oliveira VM, Gomes MAF (2013) Effect of Landscape Structure on Species Diversity. PLoS ONE 8(6): e66495.