Spatial and local environmental factors outweigh geo‐climatic gradients in structuring taxonomically and trait‐based β ‐diversity of benthic algae

2021 ◽  
Author(s):  
Naicheng Wu ◽  
Shuchan Zhou ◽  
Min Zhang ◽  
Wenqi Peng ◽  
Kun Guo ◽  
...  
2017 ◽  
Vol 68 (11) ◽  
pp. 2115 ◽  
Author(s):  
Leonardo F. B. Moreira ◽  
Tainá F. Dorado-Rodrigues ◽  
Vanda L. Ferreira ◽  
Christine Strüssmann

Species composition in floodplains is often affected by different structuring factors. Although floods play a key ecological role, habitat selection in the dry periods may blur patterns of biodiversity distribution. Here, we employed a partitioning framework to investigate the contribution of turnover and nestedness to β-diversity patterns in non-arboreal amphibians from southern Pantanal ecoregion. We investigated whether components of β-diversity change by spatial and environmental factors. We sampled grasslands and dense arboreal savannas distributed in 12 sampling sites across rainy and dry seasons, and analysed species dissimilarities using quantitative data. In the savannas, both turnover and nestedness contributed similarly to β diversity. However, we found that β diversity is driven essentially by turnover, in the grasslands. In the rainy season, balanced variation in abundance was more related to altitude and factors that induce spatial patterns, whereas dissimilarities were not related to any explanatory variable during dry season. In the Pantanal ecoregion, amphibian assemblages are influenced by a variety of seasonal constraints on terrestrial movements and biotic interactions. Our findings highlighted the role of guild-specific patterns and indicated that mass effects are important mechanisms creating amphibian community structure in the Pantanal.


2018 ◽  
Vol 69 (2) ◽  
pp. 243 ◽  
Author(s):  
N. L. Benone ◽  
R. Ligeiro ◽  
L. Juen ◽  
L. F. A. Montag

Considering the increasing importance of analysing spatial structure in ecological studies, the aims of the present study were to test whether fluvial distances and environmental factors are important drivers of the β-diversity of stream fish assemblages, and whether β-diversity is different in distinct hydrological periods. Specimens were sampled at 33 stream sites in the eastern Amazon. Eight environmental variables were measured at each site and fluvial distances between pairs of stream sites were determined. Environmental variables were the main factors structuring fish assemblages in both periods. However, fluvial distances were important only during the flood period. This can be related to the formation of extensive flood plains in this period, which increases connectivity between streams, breaking habitat isolation and increasing the regional signal for fish species. The higher correlation of β-diversity with environmental variables during the flood period may be related to decreased dispersal limitations and intermediate dispersal. Finally, β-diversity was higher during the flood period, highlighting the importance of the heterogeneity of the flood plain to stream biota. The results of the present study indicate that spatial and environmental factors play complementary roles in structuring fish assemblages in Amazon streams, and that β-diversity was affected by changes in the habitat connectivity experienced in different hydrological periods.


Forests ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1036
Author(s):  
Yang Cao ◽  
Yosihiro Natuhara

Anthropogenic disturbances pose significant threats to biodiversity. However, limited information has been acquired regarding the degree of impact human disturbance has on the β-diversity of plant assemblages, especially in threatened ecosystems (e.g., floodplains). In the present study, the effects of anthropogenic disturbance on plant communities of floodplain areas (the Miya River, Mie Prefecture, Japan) were analyzed. The taxonomic and functional β-diversity among different degradation levels were compared, and the differences were assessed by tests for homogeneity in multivariate dispersions. In addition, the effects of non-native species and environmental factors on β-diversity were analyzed. As revealed from the results, anthropogenic disturbance led to taxonomic homogenization at a regional scale. The increase in non-native invasions tended to improve homogenization, whereas at a low degradation level, the occurrence of non-natives species was usually related to taxonomic differentiation. Furthermore, though the increase in non-natives and environmental parameters significantly affected the β-diversity of the floodplain area, environmental factors may be of more crucial importance than biotic interactions in shaping species assemblages in this study. The previously mentioned result is likely to be dependent on the research scale and the extent to which floodplains are disturbed. Given the significant importance of floodplains, the significance of looking at floodplains in the different levels of degradation was highlighted, and both invasion of non-native species and environmental factors should be considered to gain insights into the response of ecosystems to anthropogenic disturbance. The findings of this study suggested that conservation programs in floodplain areas should place more emphasis on the preservation of natural processes and forest resources.


2014 ◽  
Vol 57 (2) ◽  
Author(s):  
Ahmed A. Issa ◽  
Awatief F. Hifney ◽  
Khayria M. Abdel-Gawad ◽  
Mohamed Gomaa

2019 ◽  
Vol 77 (1) ◽  
pp. 30-39
Author(s):  
Guogui Chen ◽  
Wenqing Wang ◽  
Yi Liu ◽  
Yamian Zhang ◽  
Wei Ma ◽  
...  

Abstract Determining the relative importance of ecological processes regulating the biogeographic patterns of marine species, especially with respect to α- and β-diversity in multi-habitat communities, is a central goal in marine ecology. We explored the relative contribution of spatial (stochastic processes) and environmental factors (deterministic processes) to the biogeographic patterns of the α- and β-diversity of mangrove mollusks. A total of 16 mangrove areas were sampled in southeast coast China from 18°N to 28°N latitude. The highest mean α-diversity was found at 20°N and that of β-diversity was at 21°N. Both spatial and environmental factors had significant effects on the α- and β-diversity patterns. The environments had greater effects than the spaces on shaping the α-diversity pattern, while the spaces were relatively more important in governing the β-diversity patterns than the environments. Our results suggest that the α-diversity pattern was mainly controlled by deterministic processes (environmental filtering), while β-diversity was primarily shaped by stochastic processes (dispersal-related), although both processes had significant impacts on α- and β-diversity patterns. Identifying the ecological variables and mechanisms that drive variations in α- and β-diversity may help guide the conservation for biodiversity in endangered mangrove ecosystems under anthropogenic and global changes.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Edilaine Andrade Melo ◽  
Jorge Luiz Waechter

Abstract: In recent years there has been increasing attention in patterns of β-diversity and mechanisms related to variations in species composition. In this study, we evaluated beta diversity patterns of bromeliads growing on cliffs immersed in Atlantic Forest. We hypothesized that the species composition varies according to the spatial scale, inferring that there is a replacement of species influenced mainly by environmental factors. The study was carried out on sandstone cliffs included in contiguous but distinct vegetation formations: Evergreen and Seasonal forests. Twenty-four vertical rocky outcrops were sampled. The spatial variation in species composition was evaluated by two β-diversity components, turnover and nestedness. Multivariate analysis and variation partitioning were performed to distinguish niche and stochastic processes. We recorded 26 bromeliad species and a significantly higher contribution of turnover explaining beta diversity. Environmental factors affect β-diversity patterns of Bromeliaceae. However, individually, the environmental predictors do not explain the data variation. Environmental variations spatially structured, and spatial variables determinate the dissimilarity in the composition of bromeliads on cliffs. Thus, our results revealed that both environmental and spatial effects can act together to define the floristic composition of rock-dwelling bromeliad communities.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245249
Author(s):  
Lamei Jiang ◽  
Guanghui Lv ◽  
Yanming Gong ◽  
Yan Li ◽  
Hengfang Wang ◽  
...  

Species dissimilarity (beta diversity) primarily reflects the spatio–temporal changes in the species composition of a plant community. The correlations between β diversity and environmental factors and spatial distance can be used to explain the magnitudes of environmental filtering and dispersal. However, little is known about the relative roles and importance of neutral and niche-related factors in the assemblage of plant communities with different life forms in deserts. We found that in desert ecosystems, the β diversity of herbaceous plants was the highest, followed by that of shrubs and trees. The changes in the β diversity of herbs and shrubs had stronger correlations with the environment, indicating that community aggregation was strongly affected by niche processes. The soil water content and salt content were the key environmental factors affecting species distributions of the herb and shrub layers, respectively. Spatial distance explained a larger amount of the variation in tree composition, indicating that dispersal limitation was the main factor affecting the construction of the tree layer community. The results suggest that different life forms may determine the association between organisms and the environment. These findings suggest that the spatial patterns of plant community species in the Ebinur Lake desert ecosystem are the result of the combined effects of environmental filtering and dispersal limitation.


2021 ◽  
Vol 19 (3) ◽  
Author(s):  
Gabriel L. Brejão ◽  
David J. Hoeinghaus ◽  
Camilo A. Roa-Fuentes ◽  
María Angélica Pérez-Mayorga ◽  
Silvio F. B. Ferraz ◽  
...  

Abstract High rates of deforestation, either in the past or the present, affect many of the ecological processes in streams. Integrating deforestation history and the current landscape structure enhances the evaluation of ecological effects of land-use change. This is especially true when contemporary landscape conditions are similar but the temporal path to those conditions differs. One approach that has shown promise for evaluating biodiversity responses over time and space is the β-diversity partitioning, which combines taxonomic and functional trait-based approaches. We tested hypotheses related to stream fish assemblages’ turnover in watersheds with different environmental conditions and deforestation histories. We sampled fish from 75 watersheds in the Machado River basin, Brazil, and environmental factors were quantified at multiple scales. Taxonomic turnover was higher than expected by chance, whereas functional turnover was lower than expected by the observed taxonomic turnover, indicating that deterministic processes are structuring these assemblages. The turnover, and the environmental factors differed among watersheds with different deforestation histories. Besides being scale-dependent, turnover patterns are also likely dependent on land use dynamics and involve time-lags.


2019 ◽  
Vol 42 ◽  
Author(s):  
Nicole M. Baran

AbstractReductionist thinking in neuroscience is manifest in the widespread use of animal models of neuropsychiatric disorders. Broader investigations of diverse behaviors in non-model organisms and longer-term study of the mechanisms of plasticity will yield fundamental insights into the neurobiological, developmental, genetic, and environmental factors contributing to the “massively multifactorial system networks” which go awry in mental disorders.


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