scholarly journals High dispersal levels and lake warming are emergent drivers of cyanobacterial community assembly over the Anthropocene in peri-Alpine lakes

2018 ◽  
Author(s):  
Marie-Eve Monchamp ◽  
Piet Spaak ◽  
Francesco Pomati
Keyword(s):  
Stochastic Processes ◽  
Climate Warming ◽  
Community Assembly ◽  
Sequence Data ◽  
Environmental Gradients ◽  
Spatial Scales ◽  
Alpine Lakes ◽  
Cyanobacterial Community ◽  
Water Column Stability ◽  
High Dispersal

Disentangling the relative importance of deterministic and stochastic processes in shaping natural communities is central to ecology. Studies on community assembly over broad temporal and spatial scales in aquatic microorganisms are scarce. Here, we used 16S rDNA sequence data from lake sediments to test for community assembly patterns in cyanobacterial phylogenies across ten European peri-Alpine lakes and over a century of eutrophication and climate warming. We studied phylogenetic similarity in cyanobacterial assemblages over spatial and temporal distance, and environmental gradients, comparing detected patterns with theoretical expectations from deterministic and stochastic processes. We found limited evidence for deviation of lake communities from a random assembly model and no significant effects of geographic distance on phylogenetic similarity, suggesting no dispersal limitation and high levels of stochastic assembly. We did not detect a significant effect of phosphorus and nitrogen levels on deviation of community phylogenies from random. We found however a significant decay of phylogenetic similarity for non-random communities over a gradient of air temperature and water column stability. We show how phylogenetic data from sedimentary archives can improve our understanding of microbial community assembly processes, and support previous evidence that climate warming has been the strongest environmental driver of cyanobacterial community assembly over the Anthropocene.

scholarly journals Phylogeography of two Andean frogs: Test of vicariance versus elevational gradient models of diversification

2019 ◽  
Author(s):  
Daria Koscinski ◽  
Paul Handford ◽  
Pablo L. Tubaro ◽  
Peiwen Li ◽  
Stephen C. Lougheed
Keyword(s):  
Sequence Data ◽  
Environmental Gradients ◽  
Spatial Scales ◽  
Elevational Gradient ◽  
Northwestern Argentina ◽  
Dna Sequence Data ◽  
The Andes ◽  
Common Causes ◽  
History Of ◽  
Historical Range

ABSTRACTThe tropical and subtropical Andes have among the highest levels of biodiversity in the world. Understanding the forces that underlie speciation and diversification in the Andes is a major focus of research. Here we tested two hypotheses of species origins in the Andes: 1. Vicariance mediated by orogenesis or shifting habitat distribution. 2. Parapatric diversification along elevational environmental gradients. We also sought insights on the factors that impacted the phylogeography of co-distributed taxa, and the influences of divergent species ecology on population genetic structure. We used phylogeographic and coalescent analyses of nuclear and mitochondrial DNA sequence data to compare genetic diversity and evolutionary history of two frog species: Pleurodema borellii (Family: Leiuperidae, 130 individuals; 20 sites), and Hypsiboas riojanus (Family: Hyllidae, 258 individuals; 23 sites) across their shared range in northwestern Argentina. The two showed concordant phylogeographic structuring, and our analyses support the vicariance model over the elevational gradient model. However, Pleurodema borellii exhibited markedly deeper temporal divergence (≥4 Ma) than H. riojanus (1-2 Ma). The three main mtDNA lineages of P. borellii were nearly allopatric and diverged between 4-10 Ma. At similar spatial scales, differentiation was less in the putatively more habitat-specialized H. riojanus than in the more generalist P. borellii. Similar allopatric distributions of major lineages for both species implies common causes of historical range fragmentation and vicariance. However, different divergence times among clades presumably reflect different demographic histories, permeability of different historical barriers at different times, and/or difference in life history attributes and sensitivities to historical environmental change. Our research enriches our understanding of the phylogeography of the Andes in northwestern Argentina.

scholarly journals Spatial patterns of functional diversity and composition in marine benthic ciliates along the coast of China

2019 ◽  
Vol 627 ◽  
pp. 49-60 ◽  
Author(s):  
Y Xu ◽  
J Soininen
Keyword(s):  
Functional Diversity ◽  
Large Scale ◽  
Environmental Gradients ◽  
Spatial Scales ◽  
Habitat Type ◽  
Latitudinal Gradients ◽  
Dispersal Ability ◽  
Ciliated Protozoa ◽  
High Dispersal ◽  
Benthic Ciliates

Large-scale patterns of community composition and diversity along environmental gradients have been well studied for macroorganisms. However, the biogeography of microorganisms, especially ciliated protozoa, remains understudied. Here, we analyzed a comprehensive database of marine benthic ciliates found along the coast of China from 1991 to 2018 to examine the geographical patterns in species and trait composition and functional diversity. According to redundancy analysis conducted at large spatial scales, environmental variables, i.e. habitat type and salinity, explained more variance in species composition than latitude. In contrast, trait composition was better explained by spatial and climatic variables. At small spatial scales, both species and trait composition were probably influenced by mass effects due to the high dispersal ability of ciliates at such small scales, resulting in spatially homogenized communities. Several traits, including body size, feeding type and mobility, exhibited significant positive or negative latitudinal gradients. Functional diversity showed a significant positive correlation with latitude between 20 and 40° N, which may be caused by certain groups of ciliates possessing particular traits related to temperature. Our study is the first comprehensive evaluation of how trait composition and functional diversity of marine ciliated protozoa vary at large scales and can thus make a major contribution to the study of microbial biogeography.

scholarly journals A novel framework for modeling the evolution of cross-scale ecological assembly

2020 ◽  
Author(s):  
Amanda S. Gallinat ◽  
William D. Pearse
Keyword(s):  
Community Assembly ◽  
Evolutionary Dynamics ◽  
Environmental Gradients ◽  
Spatial Scales ◽  
Regional Scale ◽  
Species Traits ◽  
Temporal And Spatial ◽  
Environmental Responses ◽  
Conceptual Overview ◽  
Species Assembly

AbstractCommunity assembly can be driven by species’ responses to environmental gradients, and interactions within (e.g., competition) and across (e.g., herbivory) clades. These ecological dynamics are mediated by species’ traits, which are in turn shaped by past evolution. As such, identifying the drivers of species assembly is made difficult by the differing temporal and spatial scales of ecological and evolutionary dynamics. Two recent advances have emerged to address the cross-scale challenge of modeling species assembly: phylogenetic generalized linear mixed modeling (PGLMM) and earth observation networks (EONs). PGLMM integrates through time by modeling the evolution of trait-based community assembly, while EONs synthesize across space by placing standardized site-level species occurrence data within their regional context. Here we describe a framework for combining these tools to investigate the drivers of species assembly, and so address three outstanding questions: (1) Does evolution adapt or constrain regional-scale environmental responses? (2) Do evolved responses to past competition minimize or enhance present-day competition? (3) Are species’ cross-clade associations evolutionarily constrained? We provide a conceptual overview of how PGLMM and EONs can be synthesized to answer these questions, and provide exemplar Bayesian PGLMM code. Finally, we describe the capacity of these tools to aid in conservation and natural resource management, including predicting future colonization by rare and invasive species, vulnerable mutualisms, and pest and pathogen outbreaks.

scholarly journals Stochastic processes dominate community assembly in cichlid communities in Lake Tanganyika

2016 ◽  
Author(s):  
Thijs Janzen ◽  
Adriana Alzate ◽  
Moritz Muschick ◽  
Fons van der Plas ◽  
Rampal S. Etienne
Keyword(s):  
Stochastic Processes ◽  
Community Assembly ◽  
Environmental Conditions ◽  
Lake Tanganyika ◽  
Environmental Gradients ◽  
Cichlid Fish ◽  
Species Traits ◽  
Ecological Processes ◽  
African Great Lakes ◽  
Community Dissimilarity

ABSTRACTThe African Great Lakes are characterized by an extraordinary diversity of endemic cichlid fish species. The cause of this diversity is still largely unknown. Most studies have tried to solve this question by focusing on macro-evolutionary processes, such as speciation. However, the ecological processes determining local cichlid diversity have so far been understudied, even though knowledge on these might be crucial for understanding larger scale biodiversity patterns.Using trait, environmental and abundance data of cichlid fishes along 36 transects, we have studied how differences in local environmental conditions influence cichlid community assembly in the littoral of Lake Tanganyika, Zambia. We investigated changes in average trait values and in trait-based community assembly processes along three key environmental gradients.Species diversity and local abundance decreased with increasing sand cover and diet-associated traits changed with depth. Analyses on within-community trait diversity patterns indicated that cichlid community assembly was mainly driven by stochastic processes, to a smaller extent by processes that limit the similarity among co-existing species and least by filtering processes that limit the range of species traits occurring in an environment. Despite, the low impact of habitat filtering processes, we find community dissimilarity to increase with increasing environmental difference.Our results suggest that local environmental conditions determine cichlid abundance, while the predominance of stochastic community assembly across all environments explains why the communities with the highest abundances contain most species.

scholarly journals Community assembly and metaphylogeography of soil biodiversity: insights from haplotype-level community DNA metabarcoding within an oceanic island

2022 ◽  
Author(s):  
Carmelo Andujar ◽  
Paula Arribas ◽  
Heriberto López ◽  
Yurena Arjona ◽  
Antonio Pérez-Delgado ◽  
...  
Keyword(s):  
Community Assembly ◽  
Sequence Data ◽  
Spatial Scales ◽  
Oceanic Island ◽  
Soil Mesofauna ◽  
Soil Biodiversity ◽  
Dna Sequence Data ◽  
Dna Metabarcoding ◽  
Patterns And Processes

Most of our understanding of island diversity comes from the study of aboveground systems, while the patterns and processes of diversification and community assembly for belowground biotas remain poorly understood. Here we take advantage of a relatively young and dynamic oceanic island to advance our understanding of eco-evolutionary processes driving community assembly within soil mesofauna. Using whole organism community DNA (wocDNA) metabarcoding and the recently developed metaMATE pipeline, we have generated spatially explicit and reliable haplotype-level DNA sequence data for soil mesofaunal assemblages sampled across the four main habitats within the island of Tenerife. Community ecological and metaphylogeographic analyses have been performed at multiple levels of genetic similarity, from haplotypes to species and supraspecific groupings. Broadly consistent patterns of local-scale species richness across different insular habitats have been found, whereas local insular richness is lower than in continental settings. Our results reveal an important role for niche conservatism as a driver of insular community assembly of soil mesofauna, with only limited evidence for habitat shifts promoting diversification. Furthermore, support is found for a fundamental role of habitat in the assembly of soil mesofauna, where habitat specialism is mainly due to colonisation and the establishment of preadapted species. Hierarchical patterns of distance decay at the community level and metaphylogeographical analyses support a pattern of geographic structuring over limited spatial scales, from the level of haplotypes through to species and lineages, as expected for taxa with strong dispersal limitations. Our results demonstrate the potential for wocDNA metabarcoding to advance our understanding of biodiversity.

scholarly journals Combined Effects of Summer Water Temperature and Current Velocity on the Distribution of a Cold-Water-Adapted Sculpin (Cottus nozawae)

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 975
Author(s):  
Kaiji Suzuki ◽  
Nobuo Ishiyama ◽  
Itsuro Koizumi ◽  
Futoshi Nakamura
Keyword(s):  
Water Temperature ◽  
Climate Warming ◽  
Current Velocity ◽  
Cold Water ◽  
Environmental Gradients ◽  
Combined Effect ◽  
Influential Factor ◽  
Combined Effects ◽  
River Catchment ◽  
Water Abstraction

Clarifying the combined effects of water temperature and other environmental factors on the species distributions of cold-water fishes is the first step toward obtaining a better understanding of the complex impacts of climate warming on these species. In the present study, we examined the abundance and occurrence of the fluvial sculpin, Cottus nozawae, in response to water temperature along environmental gradients in northern Japan. The abundance survey was conducted in the Sorachi River catchment with two-pass electrofishing with a backpack electrofisher. For the occurrence survey, we carried out one-pass electrofishing in the Sorachi, Chitose, and Tokachi River catchments. Fish sampling was conducted once from July to August 2018 in the Sorachi River catchment, from May to June 2011 in the Chitose River catchment, and from July to September 2012 in the Tokachi River catchment. Generalized linear mixed models (GLMMs) and generalized linear models (GLMs) were used for the abundance and occurrence analyses, respectively. We found that the mean summer water temperature was the most influential factor on the distribution of C. nozawae; the abundance and occurrence were both negatively affected by increased water temperatures. In the occurrence model, occurrence probabilities of 0.9 and 0.5 for C. nozawae corresponded to mean summer temperatures of 12.0 and 16.1 °C, respectively. Furthermore, we identified a combined effect of water temperature and current velocity on the abundance of C. nozawae. The increased mean summer water temperature had a stronger negative effect on C. nozawae abundance under gentle flow conditions. While the precise mechanisms of this combined effect could not be determined in this study, stressors associated with low current velocities may increase their vulnerability to higher water temperatures. Our findings indicate that flow disturbances caused by human activities such as excessive water abstraction may exacerbate the negative impacts of climate warming on populations of C. nozawae in the future.

scholarly journals Phylogenetic and Functional Traits Verify the Combined Effect of Deterministic and Stochastic Processes in the Community Assembly of Temperate Forests along an Elevational Gradient

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 591
Author(s):  
Wensong Zhou ◽  
Yuxin Zhang ◽  
Shuang Zhang ◽  
Basil N. Yakimov ◽  
Keming Ma
Keyword(s):  
Stochastic Processes ◽  
Functional Traits ◽  
Community Assembly ◽  
Woody Plants ◽  
Elevational Gradient ◽  
Combined Effect ◽  
Abiotic Environment ◽  
Spatial Factors ◽  
Assembly Mechanism ◽  
Deterministic Processes

Explaining community assembly mechanisms along elevational gradients dominated by deterministic processes or stochastic processes is a pressing challenge. Many studies suggest that phylogenetic and functional diversity are significant indicators of the process. In this study, we analyzed the structure and beta diversity of phylogenetic and functional traits along an elevational gradient and discussed the effects of environmental and spatial factors. We found that the phylogenetic and functional traits showed inconsistent changes, and their variations were closely related to the abiotic environment. The results suggested that the community assembly of woody plants was obviously affected by the combined effect of deterministic processes and the stochastic hypothesis (primarily by the latter). Phylogenetic and functional traits had a certain relationship but changed according to different rules. These results enhance our understanding of the assembly mechanism of forest communities by considering both phylogenetic and functional traits.

scholarly journals Epipelic cyanobacterial diversity in Pinang River basin, Malaysia, revealed by 16S-based metagenomic approach

Algologia ◽  
2021 ◽  
Vol 31 (1) ◽  
pp. 93-113
Author(s):  
A.R. Nur Fadzliana ◽  
◽  
W.O. Wan Maznah ◽  
S.A.M. Nor ◽  
Choon Pin Foong ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
River Basin ◽  
Sequence Data ◽  
Diversity Index ◽  
Saline Water ◽  
Illumina Miseq ◽  
Rrna Gene ◽  
Cyanobacterial Community ◽  
Upstream Station

Cyanobacteria are the most widespread group of photosynthetic prokaryotes. They are primary producers in a wide variety of habitats and are able to thrive in harsh environments, including polluted waters; therefore, this study was conducted to explore the cyanobacterial populations inhabiting river tributaries with different levels of pollution. Sediment samples (epipelon) were collected from selected tributaries of the Pinang River basin. Air Terjun (T1) and Air Itam rivers (T2) represent the upper streams of Pinang River basin, while Dondang (T3) and Jelutong rivers (T4) are located at in the middle of the river basin. The Pinang River (T5) is located near the estuary and is subjected to saline water intrusion during high tides. Cyanobacterial community was determined by identifying the taxa via 16S rRNA gene amplicon sequence data. 16S rRNA gene amplicons generated from collected samples were sequenced using illumina Miseq, with the targeted V3 and V4 regions yielding approximately 1 mln reads per sample. Synechococcus, Phormidium, Arthronema and Leptolyngbya were found in all samples. Shannon-Weiner diversity index was highest (H’ = 1.867) at the clean upstream station (T1), while the moderately polluted stream (T3) recorded the lowest diversity (H’ = 0.399), and relatively polluted stations (T4 and T5) recorded fairly high values of H’. This study provides insights into the cyanobacterial community structure in Pinang River basin via cultivation-independent techniques using 16S rRNA gene amplicon sequence. Occurrence of some morphospecies at specific locations showed that the cyanobacterial communities are quite distinct and have specific ecological demands. Some species which were ubiquitous might be able to tolerate varied environmental conditions.

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