scholarly journals Climate and geographic distance are more influential than rivers on the beta diversity of passerine birds in Amazonia

Ecography ◽  
2020 ◽  
Vol 43 (6) ◽  
pp. 860-868 ◽  
Author(s):  
Isadora E. Fluck ◽  
Nilton Cáceres ◽  
Carla D. Hendges ◽  
Mariana do Nascimento Brum ◽  
Cristian S. Dambros
Keyword(s):  
Beta Diversity ◽  
Geographic Distance ◽  
Passerine Birds

scholarly journals Geographic distance and vegetation structure rather than river barrier drive ant beta diversity across Central Amazonia

2021 ◽  
Author(s):  
Diego Rodrigues Guilherme ◽  
Pedro Aurélio Costa Lima Pequeno ◽  
Fabrício Beggiato Baccaro ◽  
Elizabeth Franklin ◽  
Cláudio Rabelo dos Santos Neto ◽  
...  
Keyword(s):  
Indirect Effects ◽  
Vegetation Structure ◽  
Beta Diversity ◽  
Amazon Basin ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Effect Of Temperature ◽  
Detectable Effect ◽  
Direct And Indirect Effects ◽  
Central Amazonia

Abstract To understand better the effects of niche and neutral processes is important to disentangle the direct and indirect effects of each process, mainly if the environmental factors are geographically structured neglecting important indirect and synergic effects. We sampled ground-dwelling ant species on 126 plots distributed across eight sampling sites along a broad environmental gradient in Central Amazonia. Structural equation modelling was employed to quantify direct and indirect effects of geographic distance, the Amazon River’s opposite margins, and environmental differences in temperature, precipitation and vegetation structure (Normalized Difference Vegetation Index) on ant beta diversity (Jaccard’s dissimilarity). We found that geographic distance and NDVI differences had major direct effects on ant beta diversity. The major effect of temperature was indirect through NDVI, whereas precipitation had no detectable effect on beta diversity. The Amazon River had a weak influence on the ant composition dissimilarity. Our results challenge the major role often ascribed to riverine barriers in the diversification and distribution of Amazonian biota. Rather, ant compositional dissimilarity seems to be mainly driven by a combination of dispersal limitation and selection imposed by vegetation features and, indirectly, by temperature. We suggest that as NDVI differences decrease with geographic distance in the region, isolation by distance may have favoured phenotypic convergence between ant communities in the northern and southern borders of the Amazon Basin.

Environmental correlates of herpetofaunal diversity in Costa Rica

2010 ◽  
Vol 26 (5) ◽  
pp. 521-531 ◽  
Author(s):  
David Laurencio ◽  
Lee A. Fitzgerald
Keyword(s):  
Costa Rica ◽  
Species Diversity ◽  
Beta Diversity ◽  
Geographic Distance ◽  
Alpha Diversity ◽  
High Elevation ◽  
Diversity Patterns ◽  
Regional Diversity ◽  
Environmental Correlates ◽  
High Elevation Site

Abstract:Disentangling local and historical factors that determine species diversity patterns at multiple spatial scales is fundamental to elucidating processes that govern ecological communities. Here we investigated how environmental correlates may influence diversity at local and regional scales. Primarily utilizing published species lists, amphibian and reptile alpha and beta diversity were assessed at 17 well-surveyed sites distributed among ecoregions throughout Costa Rica. The degree to which regional species diversity patterns were related to environmental variables and geographic distance was determined using Canonical Correspondence Analysis and Mantel tests. Amphibian alpha diversity was highest in lowland Pacific sites (mean = 43.3 species) and lowest at the high elevation site (9 species). Reptile alpha diversity values were high for both lowland Atlantic (mean = 69.5 species) and lowland Pacific (mean = 67 species) sites and lowest for the high elevation site (8 species). We found high species turnover between local sites and ecoregions, demonstrating the importance of beta diversity in the determination of regional diversity. For both amphibians and reptiles, beta diversity was highest between the high-elevation site and all others, and lowest among lowland sites within the same ecoregion. The effect of geographic distance on beta diversity was minor. Ecologically significant climatic variables related to rain, temperature, sunshine and insolation were found to be important determinants of local and regional diversity for both amphibians and reptiles in Costa Rica.

scholarly journals Factors that influence the beta-diversity of spider communities in northwestern Argentinean Grasslands

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1946 ◽  
Author(s):  
Sandra M. Rodriguez-Artigas ◽  
Rodrigo Ballester ◽  
Jose A. Corronca
Keyword(s):  
Beta Diversity ◽  
Environmental Variables ◽  
Regional Scale ◽  
Geographic Distance ◽  
Species Replacement ◽  
Community Similarity ◽  
Dispersal Capacity ◽  
Assembly Structure ◽  
Dispersion Capacity ◽  
Spider Communities

Beta-diversity, defined as spatial replacement in species composition, is crucial to the understanding of how local communities assemble. These changes can be driven by environmental or geographic factors (such as geographic distance), or a combination of the two. Spiders have been shown to be good indicators of environmental quality. Accordingly, spiders are used in this work as model taxa to establish whether there is a decrease in community similarity that corresponds to geographic distance in the grasslands of the Campos & Malezales ecoregion (Corrientes). Furthermore, the influence of climactic factors and local vegetation heterogeneity (environmental factors) on assemblage composition was evaluated. Finally, this study evaluated whether the differential dispersal capacity of spider families is a factor that influences their community structure at a regional scale. Spiders were collected with a G-Vac from vegetation in six grassland sites in the Campos & Malezales ecoregion that were separated by a minimum of 13 km. With this data, the impact of alpha-diversity and different environmental variables on the beta-diversity of spider communities was analysed. Likewise, the importance of species replacement and nesting on beta-diversity and their contribution to the regional diversity of spider families with different dispersion capacities was evaluated. The regional and site-specific inventories obtained were complete. The similarity between spider communities declined as the geographic distance between sites increased. Environmental variables also influenced community composition; stochastic events and abiotic forces were the principal intervening factors in assembly structure. The differential dispersal capacity of spider groups also influenced community structure at a regional scale. The regional beta-diversity, as well as species replacement, was greater in high and intermediate vagility spiders; while nesting was greater in spiders with low dispersion capacity. Geographic distance, among other factors (climate, and active and passive dispersion capacity), explains assembly structure and the decrease spider community similarity between geographically distant sites. Spiders with the highest dispersal capacity showed greater species replacement. This may be due to the discontinuity (both natural and anthropic) of the grasslands in this ecoregion, which limits the dispersal capacity of these spiders, and their close dependence on microhabitats. The dispersal capacity of the least vagile spiders is limited by geographic distance and biotic factors, such as competition, which could explain the nesting observed between their communities.

scholarly journals Contrasting beta diversity and functional composition of aquatic insect communities across local to regional scales in Amazonian streams

2020 ◽  
Author(s):  
Gilberto Nicacio ◽  
Erlane José Cunha ◽  
Neusa Hamada ◽  
Leandro Juen
Keyword(s):  
Beta Diversity ◽  
Geographic Distance ◽  
Aquatic Insect ◽  
Procrustes Analysis ◽  
Functional Composition ◽  
Species Replacement ◽  
Environmental Predictors ◽  
Insect Communities ◽  
Trait Convergence ◽  
Community Dissimilarity

AbstractWe investigated how components of beta diversity (i.e., the turnover and nestedness and functional compositional) aquatic insect assemblages change among sites and are influenced by environmental and spatial drivers. For this, we analyzed beta-diversity and functional composition of Ephemeroptera, Plecoptera, and Trichoptera in 16 streams in two Amazonian basins with distinct environmental conditions (the Carajás and Tapajós regions). We performed Multiple regression on dissimilarity matrices (MRM) and Procrustes analysis to test spatial and environmental influences on the taxonomic and functional composition of communities. Community dissimilarity was most related to variations in geographic distance and topography, which highlighted the environmental distances shaping the communities. Variation in functional composition could be mostly attributed to the replacement of species by those with similar traits, indicating trait convergence among communities. Environmental predictors best-explained species replacement and trait congruence within and between the regions evaluated. In summary, among communities with different taxonomic compositions, the high species replacement observed appears to be leading them to have similar community structure, with species having the same functional composition, even in communities separated by both small and large geographic distances.

Influence of environmental heterogeneity and geographic distance on beta-diversity of woody communities

Plant Ecology ◽  
2020 ◽  
Vol 221 (7) ◽  
pp. 595-614
Author(s):  
Ernesto Vega ◽  
Miguel Martínez-Ramos ◽  
Felipe García-Oliva ◽  
Ken Oyama
Keyword(s):  
Beta Diversity ◽  
Environmental Heterogeneity ◽  
Geographic Distance

scholarly journals Frog species richness, composition and beta-diversity in coastal Brazilian restinga habitats

2008 ◽  
Vol 68 (1) ◽  
pp. 101-107 ◽  
Author(s):  
CFD. Rocha ◽  
FH. Hatano ◽  
D. Vrcibradic ◽  
M. Van Sluys
Keyword(s):  
Species Richness ◽  
Beta Diversity ◽  
Habitat Degradation ◽  
Species Turnover ◽  
Geographic Distance ◽  
Sampling Procedure ◽  
Brazilian Coast ◽  
Historical Factors ◽  
Frog Species ◽  
Diurnal Species

We studied the species richness and composition of frogs in 10 restinga habitats (sand dune environments dominated by herbaceous and shrubby vegetation) along approximately 1500 km of coastal areas of three Brazilian States: Rio de Janeiro (Grumari, Maricá, Massambaba, Jurubatiba and Grussaí), Espírito Santo (Praia das Neves and Setiba) and Bahia (Prado and Trancoso). We estimated beta-diversity and similarity among areas and related these parameters to geographic distance between areas. All areas were surveyed with a similar sampling procedure. We found 28 frog species belonging to the families Hylidae, Microhylidae, Leptodactylidae and Bufonidae. Frogs in restingas were in general nocturnal with no strictly diurnal species. The richest restinga was Praia das Neves (13 species), followed by Grussaí and Trancoso (eight species in each). The commonest species in the restingas was Scinax alter (found in eight restingas), followed by Aparasphenodon brunoi (seven areas). Our data shows that richness and composition of frog communities vary consistently along the eastern Brazilian coast and, in part, the rate of species turnover is affected by the distance among areas. Geographic distance explained approximately 12% of species turnover in restingas and about 9.5% of similarity among frog assemblages. Although geographic distance somewhat affects frog assemblages, other factors (e.g. historical factors, disturbances) seem to be also involved in explaining present frog assemblage composition in each area and species turnover among areas. The frog fauna along restinga habitats was significantly nested (matrix community temperature = 26.13°; p = 0.007). Our data also showed that the most hospitable restinga was Praia das Neves and indicated that this area should be protected as a conservation unit. Frog assemblage of each area seems to partially represent a nested subset of the original assemblage, although we should not ignore the importance of historical factors. This nestedness pattern, in part, probably results from the intensive fragmentation of restinga habitats. Possibly, many frog species may have been lost in some studied areas as a result of the extensive habitat degradation to which restinga habitats are presently exposed.

Species turnover drives the spatial distribution of frog beta diversity in farmland ponds

2019 ◽  
Vol 35 (4) ◽  
pp. 199-202 ◽  
Author(s):  
Henrique Nascimento Tavares ◽  
Fernando Rodrigues da Silva
Keyword(s):  
Spatial Distribution ◽  
Species Composition ◽  
Beta Diversity ◽  
Agricultural Landscape ◽  
Species Turnover ◽  
Land Use Changes ◽  
Geographic Distance ◽  
Forest Fragment ◽  
Inappropriate Use ◽  
Anuran Species

AbstractStudies integrating variation in species composition among sites are useful in understanding the impacts of land-use changes on the spatial distribution of biodiversity. However, the failure to recognize the distinction between beta diversity components, dissimilarity due to species replacement (i.e. turnover) and dissimilarity due to species loss from site to site (i.e. nestedness), can lead to inappropriate use of some indices. Here, we evaluated how the spatial distribution of anuran beta diversity components, turnover and nestedness, is associated with local and landscape descriptors in a tropical agricultural landscape with a recent history of agriculture expansion in south-eastern Brazil. Overall, 27 anuran species were found in the region with average ± SD species richness in each pool of 9.5 ± 3.5 species, ranging from 4 to 15 species. We observed that species turnover was the major component for anuran dissimilarity among pools, indicating that anuran species occurring in species-poor pools are not subsets of anuran species occurring in species-rich pools. Local variables and geographic distance were not important descriptors explaining the variation of anuran beta diversity. In contrast, the distance of the pools to the nearest forest fragment explained 16% of the variance in total beta diversity, 5% of the nestedness component and 2% of spatial turnover. Our results show that pools distributed across farmland landscapes are harbouring different anuran species composition, and together, these pools are contributing to the regional diversity of anurans in this region which is considered one of the most deforested and fragmented within Brazil.

Alpha- and beta- diversity of woody species across environmental gradients in African and Australian tropical savannas

2020 ◽  
Author(s):  
Felix Trotter ◽  
Caroline Lehmann ◽  
Keyword(s):  
Beta Diversity ◽  
Woody Plant ◽  
Environmental Gradients ◽  
Species Turnover ◽  
Geographic Distance ◽  
Alpha Diversity ◽  
Woody Species ◽  
Mean Annual Temperature ◽  
Alpha And Beta Diversity ◽  
Rainfall Seasonality

<p>Patterns of woody plant diversity in the tropical savanna biome has received little research attention but is relevant to understanding the complex vegetation dynamics of a biome that have remained contentious for almost a century. Tropical savannas of Africa and Australia are defined by the co-existence of woody plants and grasses, and the evolution and assembly of the savanna biome trace back 3-10 million years. Here, we explored patterns of local (alpha-) diversity and species turnover (beta-diversity) of woody plant species across African and Australian savannas. We aimed test the relative role of the environmental gradients of rainfall, temperature, fire and soil in shaping the relative abundance of all of woody species, genera, and families. Using generalized additive models (GAMs) and generalised dissimilarity models (GDMs) of field inventory data from vegetation plots across sub-Saharan Africa and Northern Australia we analysed changes in alpha- and beta-diversity. Environmental gradients were characterised as effective rainfall (ER), rainfall seasonality (coefficient of variation of monthly rainfall), mean annual temperature (MAT), temperature seasonality, fire frequency, and cation exchange capacity (CEC) in soils.</p><p>Savannas in Australia are on average drier and hotter than in Africa likely as a product of lower altitude. Crucially, diversity across all taxonomic levels is approximately two to three times greater in Africa compared with Australia. Within each continent, rainfall seasonality was the strongest environmental correlate of both alpha- and beta-diversity. In Africa, there is a strongly negative relationship between alpha-diversity at all taxonomic levels and rainfall seasonality. In contrast, in Australia, the relationship between alpha-diversity and rainfall seasonality while relevant is non-linear. Surprisingly within continents, rainfall, temperature, soils and fire had little bearing in these data on patterns of alpha diversity.</p><p>In terms of beta-diversity, and likely linked to the overall differences in diversity between continents, the geographic distance equalling total species turnover is greater in Australia than in Africa. Effective rainfall was the only additional significant correlate of woody species turnover in Australia, but only in arid regions. In Australia, at higher taxonomic levels the capacity of GDMs to explain variation in the data diminished substantially as a product of low diversity in genera and families. When compared to Australia, species turnover in Africa increases when geographic distance, rainfall seasonality and mean annual temperature are relatively low.</p><p>Our findings highlight that with ongoing climate change specifically with shifts in rainfall distribution that will also affect local drought regimes, rainfall seasonality could substantially alter patterns of diversity, specifically in Africa. There have been persistent attempts to explain ecosystem dynamics in savannas with respect to climate, soils and fire with emphasis often on total rainfall, but our findings suggest that rainfall seasonality can have strong effects on diversity that may interact with other environmental correlates such as fire.</p>

scholarly journals Functional randomness despite high taxonomic turnover across an elevational gradient in a global biodiversity hotspot: A case study of hawkmoths and birds

2019 ◽  
Author(s):  
Mansi Mungee ◽  
Ramana Athreya
Keyword(s):  
Beta Diversity ◽  
Species Turnover ◽  
Geographic Distance ◽  
Elevational Gradient ◽  
Diversity Indices ◽  
Northeast India ◽  
Biodiversity Hotspot ◽  
Global Biodiversity ◽  
Patterns And Processes ◽  
Generalized Dissimilarity Modeling

AbstractAimWe examined the patterns and processes of taxonomic and functional dissimilarities for two disparate organismal groups (ectothermic hawkmoths and endothermic birds) across a broad tropical elevational gradient.LocationEaglenest Wildlife Sanctuary (northeast India), eastern Himalayan global biodiversity hotspot.Taxon4,731 hawkmoths; 15,387 birdsMethodsTurnover and nestedness components for taxonomic and functional dissimilarities were obtained using the methods developed by Baselga (2013) and Leprieur et al., 2012. We used Generalized Dissimilarity Modeling (GDM) with geographic distance, contemporary and historic climatic variables to assess the relative importance of dispersal and environmental processes in determining the beta diversity. Functional redundancy (FRed) was calculated for both organismal groups using the Simpson’s diversity indices. Null modeling was used to determine randomness in species and trait distributions.ResultsTurnover dominated taxonomic and functional dissimilarities, however the contribution of nestedness was considerably higher to the latter. Overall, the rate of dissimilarity with distance, for both facets of diversity, was significantly higher for birds, with stronger contributions of geographic distance and historic climate; whereas the hawkmoth dissimilarities were strongly correlated with only contemporary climate. Taxonomic dissimilarities deviated significantly from null, whereas functional dissimilarities exhibited high redundancy and randomness.Main ConclusionsOverall, our results suggest that while the drivers of beta-diversity exhibit idiosyncrasy and taxon-specificity; for a given taxa, they are consistent across the two facets of dissimilarity. More importantly, regardless of the principal predictor, the net result was that of high taxonomic turnover, which is de-coupled to a high degree from functional turnover in these tropical ecosystems. The large redundancy in trait values, despite high species turnover, indicates functional resilience of these tropical communities. The consistency of this pattern, across two disparate organismal groups, is suggestive of a key mechanism in which tropical communities may retain functionality of ecosystems in a changing environment.

scholarly journals The relative importance of stochastic and deterministic processes on bryophyte community assembly changes with scale

2021 ◽  
Author(s):  
Nagore Medina ◽  
Joaquin Calatayud ◽  
Richard Ladle ◽  
Francisco Lara ◽  
Isabel Draper ◽  
...  
Keyword(s):  
Species Composition ◽  
Beta Diversity ◽  
Environmental Gradients ◽  
Geographic Distance ◽  
Small Scale ◽  
Stochastic Effects ◽  
Network Analyses ◽  
Biogeographic Region ◽  
Deterministic Processes ◽  
The Impact

Studies focused on the drivers of change in species composition often fail to integrate several aspects of beta diversity and scale. Here, we assess the impact of species pool, environmental gradients, geographic distance, and spatial scale on the diversity of epiphytic bryophytes. We identify biogeographic modules of co-occurring species using network analyses. For each biogeographic unit we study the effects of environment, abundance structure of the community and geographic distance on beta diversity. We analyse two aspects of beta diversity related to different scales of analysis: between-forests dissimilarity in species composition and within-forests heterogeneity in species composition. We show that the structuring of the communities is a by-product of niche-related and stochastic processes. The balance of these processes changes with biogeographic region and scale, neutral stochastic effects are more significant in the most favourable regions and for small-scale within-forest heterogeneity

Sign in / Sign up

Export Citation Format

Share Document