scholarly journals Dispersal, environmental niches and oceanic-scale turnover in deep-sea bivalves

2011 ◽  
Vol 279 (1735) ◽  
pp. 1993-2002 ◽  
Author(s):  
Craig R. McClain ◽  
James C. Stegen ◽  
Allen H. Hurlbert
Keyword(s):  
Deep Sea ◽  
Environmental Filtering ◽  
Dispersal Limitation ◽  
Environmental Variable ◽  
Distance Decay ◽  
Spatial Distance ◽  
Explanatory Variables ◽  
Faunal Turnover ◽  
Theoretical Predictions ◽  
Rates Of Decay

Patterns of beta-diversity or distance decay at oceanic scales are completely unknown for deep-sea communities. Even when appropriate data exist, methodological problems have made it difficult to discern the relative roles of environmental filtering and dispersal limitation for generating faunal turnover patterns. Here, we combine a spatially extensive dataset on deep-sea bivalves with a model incorporating ecological dynamics and shared evolutionary history to quantify the effects of environmental filtering and dispersal limitation. Both the model and empirical data are used to relate functional, taxonomic and phylogenetic similarity between communities to environmental and spatial distances separating them for 270 sites across the Atlantic Ocean. This study represents the first ocean-wide analysis examining distance decay as a function of a broad suite of explanatory variables. We find that both strong environmental filtering and dispersal limitation drive turnover in taxonomic, functional and phylogenetic composition in deep-sea bivalves, explaining 26 per cent, 34 per cent and 9 per cent of the variation, respectively. This contrasts with previous suggestions that dispersal is not limiting in broad-scale biogeographic and biodiversity patterning in marine systems. However, rates of decay in similarity with environmental distance were eightfold to 44-fold steeper than with spatial distance. Energy availability is the most influential environmental variable evaluated, accounting for 3.9 per cent, 9.4 per cent and 22.3 per cent of the variation in functional, phylogenetic and taxonomic similarity, respectively. Comparing empirical patterns with process-based theoretical predictions provided quantitative estimates of dispersal limitation and niche breadth, indicating that 95 per cent of deep-sea bivalve propagules will be able to persist in environments that deviate from their optimum by up to 2.1 g m −2 yr −1 and typically disperse 749 km from their natal site.

scholarly journals Vertical stratification of microbial communities in woody plants

2021 ◽  
Author(s):  
Mohammad Bahram ◽  
Kati Kings ◽  
Mari Pent ◽  
Sergei Polme ◽  
Daniyal Gohar ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Community Assembly ◽  
Boreal Forests ◽  
Fungal Endophytes ◽  
Environmental Filtering ◽  
Dispersal Limitation ◽  
Distribution Patterns ◽  
Fungal Communities ◽  
Spatial Distance ◽  
Related Factors

Bacterial and fungal endophytes form diverse communities and contribute to the performance and health of their host plants. Recent evidence suggests that both host related factors and environmental conditions determine the community structure of plant endophytes. Yet, we know little about their distribution patterns, and underlying community assembly mechanisms across plant compartments. Here we analysed the structure of bacterial and fungal communities associated with tree compartments as well as their underlying soils across 12 tree individuals in boreal forests. We found that the structure of bacterial and fungal communities depends more strongly on the vertical location of tree compartments rather than the locality, species, and individuals of host trees. Microbial communities showed much stronger host specificity in aboveground than belowground compartments. While having lower compartment community variability compared to fungi, bacterial communities were markedly more distinct between below- and aboveground components but not between hosts, reflecting the greater importance of environmental filtering rather than dispersal limitation and host identity in their community assembly. Our data suggest that spatial distance from soil as a major microbiome source contributes to the formation of microbiomes in plants, and that bacterial and fungal communities may follow contrasting assembly processes.

scholarly journals Dormancy dampens the microbial distance-decay relationship

2019 ◽  
Author(s):  
KJ Locey ◽  
ME Muscarella ◽  
ML Larsen ◽  
SR Bray ◽  
SE Jones ◽  
...  
Keyword(s):  
Environmental Filtering ◽  
Distance Decay ◽  
Regional Survey ◽  
Geographical Patterns ◽  
Local Diversity ◽  
Theoretical Predictions ◽  
Active Portion ◽  
Total Community ◽  
Total Dna ◽  
New Habitats

ABSTRACTMuch of Earth’s biodiversity has the capacity to engage in dormancy whereby individuals enter a reversible state of reduced metabolic activity. By increasing resilience to unfavorable conditions, dormancy leads to the accumulation of “seed banks” that should diminish the influence of environmental filtering, while allowing passive dispersers to colonize new habitats. Although prevalent among single-celled organisms, evidence that dormancy influences patterns of microbial biodiversity and biogeography is lacking. We constructed geographical and environmental distance-decay relationships (DDRs) using 16S rRNA sequencing to characterize the total (DNA) and the active (RNA) bacterial communities in a regional survey of 49 forested ponds. As expected, the total community harbored greater diversity and exhibited weaker DDRs than the active portion of the community. These empirical observations were robust to different measures of community similarity and random resampling tests. Furthermore, findings from the field survey were reproduced by models that included aspects of dormancy along with the geographical coordinates and environmental characteristics of our study system. In addition to maintaining local diversity, our results support recent theoretical predictions that dormancy shapes geographical patterns of biodiversity.

scholarly journals Characteristics and driving mechanisms of species beta diversity in desert plant communities

PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0245249
Author(s):  
Lamei Jiang ◽  
Guanghui Lv ◽  
Yanming Gong ◽  
Yan Li ◽  
Hengfang Wang ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Plant Community ◽  
Plant Communities ◽  
Beta Diversity ◽  
Environmental Filtering ◽  
Dispersal Limitation ◽  
Life Forms ◽  
Desert Ecosystem ◽  
Spatial Distance ◽  
Β Diversity

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.

scholarly journals Dormancy dampens the microbial distance–decay relationship

2020 ◽  
Vol 375 (1798) ◽  
pp. 20190243 ◽  
Author(s):  
K. J. Locey ◽  
M. E. Muscarella ◽  
M. L. Larsen ◽  
S. R. Bray ◽  
S. E. Jones ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Regional Scale ◽  
Environmental Filtering ◽  
Model Performance ◽  
Seed Banks ◽  
Distance Decay ◽  
Biogeographic Patterns ◽  
Microbial Community Ecology ◽  
Theoretical Predictions ◽  
Total Dna

Much of Earth's biodiversity has the capacity to engage in dormancy, a reversible state of reduced metabolic activity. By increasing resilience to unfavourable conditions, dormancy leads to the accumulation of ‘seed banks’. These reservoirs of genetic and phenotypic diversity should diminish the strength of environmental filtering and increase rates of dispersal. Although prevalent among single-celled organisms, evidence that dormancy influences patterns of microbial biogeography is lacking. We constructed geographical and environmental distance–decay relationships (DDRs) for the total (DNA) and active (RNA) portions of bacterial communities in a regional-scale 16S rRNA survey of forested ponds in Indiana, USA. As predicted, total communities harboured greater diversity and exhibited weaker DDRs than active communities. These observations were robust to random resampling and different community metrics. To evaluate the processes underlying the biogeographic patterns, we developed a platform of mechanistic models that used the geographical coordinates and environmental characteristics of our study system. Based on more than 10 6 simulations, our models approximated the empirical DDRs when there was strong environmental filtering along with the presence of long-lived seed banks. By contrast, the inclusion of dispersal generally decreased model performance. Together, our findings support recent theoretical predictions that seed banks can influence the biogeographic patterns of microbial communities. This article is part of the theme issue ‘Conceptual challenges in microbial community ecology’.

scholarly journals Local-scale determinants of arboreal spider beta diversity in a temperate forest: roles of tree architecture, spatial distance, and dispersal capacity

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5596 ◽  
Author(s):  
Qiongdao Zhang ◽  
Dong He ◽  
Hua Wu ◽  
Wei Shi ◽  
Cong Chen
Keyword(s):  
Beta Diversity ◽  
Environmental Gradient ◽  
Dispersal Limitation ◽  
Local Scale ◽  
Tree Architecture ◽  
Habitat Specialization ◽  
Spatial Distance ◽  
Species Variation ◽  
Dispersal Capacity ◽  
Canopy Volume

Spiders are a functionally important taxon in forest ecosystems, but the determinants of arboreal spider beta diversity are poorly understood at the local scale. We examined spider assemblages in 324 European beech (Fagus sylvatica) trees of varying sizes across three forest stands in Würzburg (Germany) to disentangle the roles of tree architecture, spatial distance, and dispersal capacity on spider turnover across individual trees. A large proportion of tree pairs (66%) showed higher compositional dissimilarity in spider assemblages than expected by chance, suggesting prominent roles of habitat specialization and/or dispersal limitation. Trees with higher dissimilarity in DBH and canopy volume, and to a lesser extent in foliage cover, supported more dissimilar spider assemblages, suggesting that tree architecture comprised a relevant environmental gradient of sorting spider species. Variation partitioning revealed that 28.4% of the variation in beta diversity was jointly explained by tree architecture, spatial distance (measured by principal coordinates of neighbor matrices) and dispersal capacity (quantified by ballooning propensity). Among these, dispersal capacity accounted for a comparable proportion as spatial distance did (6.8% vs. 5.9%). Beta diversity did not significantly differ between high- and low-vagility groups, but beta diversity in species with high vagility was more strongly determined by spatially structured environmental variation. Altogether, both niche specialization, along the environmental gradient defined by tree architecture, and dispersal limitation are responsible for structuring arboreal spider assemblages. High dispersal capacity of spiders appears to reinforce the role of niche-related processes.

scholarly journals Assembly processes of gastropod community change with horizontal and vertical zonation in ancient Lake Ohrid: a metacommunity speciation perspective

2016 ◽  
Vol 13 (10) ◽  
pp. 2901-2911 ◽  
Author(s):  
Torsten Hauffe ◽  
Christian Albrecht ◽  
Thomas Wilke
Keyword(s):  
Community Composition ◽  
Community Assembly ◽  
Environmental Filtering ◽  
Dispersal Limitation ◽  
Species Interaction ◽  
Relative Importance ◽  
Lake Depth ◽  
Ancient Lake ◽  
Lake Ohrid ◽  
Speciation Model

Abstract. The Balkan Lake Ohrid is the oldest and most diverse freshwater lacustrine system in Europe. However, it remains unclear whether species community composition, as well as the diversification of its endemic taxa, is mainly driven by dispersal limitation, environmental filtering, or species interaction. This calls for a holistic perspective involving both evolutionary processes and ecological dynamics, as provided by the unifying framework of the “metacommunity speciation model”.The current study used the species-rich model taxon Gastropoda to assess how extant communities in Lake Ohrid are structured by performing process-based metacommunity analyses. Specifically, the study aimed (1) to identifying the relative importance of the three community assembly processes and (2) to test whether the importance of these individual processes changes gradually with lake depth or discontinuously with eco-zone shifts.Based on automated eco-zone detection and process-specific simulation steps, we demonstrated that dispersal limitation had the strongest influence on gastropod community composition. However, it was not the exclusive assembly process, but acted together with the other two processes – environmental filtering and species interaction. The relative importance of the community assembly processes varied both with lake depth and eco-zones, though the processes were better predicted by the latter.This suggests that environmental characteristics have a pronounced effect on shaping gastropod communities via assembly processes. Moreover, the study corroborated the high importance of dispersal limitation for both maintaining species richness in Lake Ohrid (through its impact on community composition) and generating endemic biodiversity (via its influence on diversification processes). However, according to the metacommunity speciation model, the inferred importance of environmental filtering and biotic interaction also suggests a small but significant influence of ecological speciation. These findings contribute to the main goal of the Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOPSCO) deep drilling initiative – inferring the drivers of biotic evolution – and might provide an integrative perspective on biological and limnological dynamics in ancient Lake Ohrid.

scholarly journals The roles of environmental variation and spatial distance in explaining diversity and biogeography of soil denitrifying communities in remote Tibetan wetlands

2020 ◽  
Vol 96 (5) ◽  
Author(s):  
Xiaoliang Jiang ◽  
Wenzhi Liu ◽  
Lunguang Yao ◽  
Guihua Liu ◽  
Yuyi Yang
Keyword(s):  
Electrical Conductivity ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Community Composition ◽  
Environmental Filtering ◽  
Operational Taxonomic Unit ◽  
Amplicon Sequencing ◽  
Spatial Distance ◽  
Wetland Type ◽  
Α Diversity

ABSTRACT The relative importance of local environments and dispersal limitation in shaping denitrifier community structure remains elusive. Here, we collected soils from 36 riverine, lacustrine and palustrine wetland sites on the remote Tibetan Plateau and characterized the soil denitrifier communities using high-throughput amplicon sequencing of the nirS and nirK genes. Results showed that the richness of nirS-type denitrifiers in riverine wetlands was significantly higher than that in lacustrine wetlands but not significantly different from that in palustrine wetlands. There was no clear distinction in nir community composition among the three kinds of wetlands. Irrespective of wetland type, the soil denitrification rate was positively related to the abundance, but not the α-diversity, of denitrifying communities. Soil moisture, carbon availability and soil temperature were the main determinants of diversity [operational taxonomic unit (OTU) number] and abundance of thenirS-type denitrifier community, while water total organic carbon, soil NO3– and soil moisture were important in controlling nirK-type denitrifier diversity and abundance. The nirS community composition was influenced by water electrical conductivity, soil temperature and water depth, while the nirK community composition was affected by soil electrical conductivity. Spatial distance explained more variation in the nirS community composition than in the nirK community composition. Our findings highlight the importance of both environmental filtering and spatial distance in explaining diversity and biogeography of soil nir communities in remote and relatively undisturbed wetlands.

scholarly journals Distance-Decay Relationships Partially Determine Diversity Patterns of Phyllosphere Bacteria on Tamrix Trees across the Sonoran Desert

2012 ◽  
Vol 78 (17) ◽  
pp. 6187-6193 ◽  
Author(s):  
Omri M. Finkel ◽  
Adrien Y. Burch ◽  
Tal Elad ◽  
Susan M. Huse ◽  
Steven E. Lindow ◽  
...  
Keyword(s):  
Sonoran Desert ◽  
Dispersal Limitation ◽  
Climatic Conditions ◽  
Distance Decay ◽  
Rrna Gene ◽  
Content Type ◽  
Leaf Surfaces ◽  
16S Rrna Gene Pyrosequencing ◽  
Community Dissimilarity ◽  
Significant Distance

ABSTRACTDispersal limitation in phyllosphere communities was measured on the leaf surfaces of salt-excretingTamarixtrees, which offer unique, discrete habitats for microbial assemblages. We employed 16S rRNA gene pyrosequencing to measure bacterial community dissimilarity on leaves of spatially dispersedTamarixspecimens in sites with uniform climatic conditions across the Sonoran Desert in the Southwestern United States. Our analyses revealed diverse bacterial communities with four dominant phyla that exhibited differential effects of environmental and geographic variables. Geographical distance was the most important parameter that affected community composition, particularly that of betaproteobacteria, which displayed a statistically significant, distance-decay relationship.

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