scholarly journals Hydraulic diversity of El Cien Formation (Baja California Sur, Mexico) and the consequences of functional diversity in paleoclimate estimation using fossil wood

2019 ◽  
Author(s):  
Hugo I. Martínez-Cabrera ◽  
Emilio Estrada-Ruiz
Keyword(s):  
Functional Diversity ◽  
Community Assembly ◽  
Environmental Filtering ◽  
Fossil Wood ◽  
Limiting Similarity ◽  
Environmental Filter ◽  
Climate Gradients ◽  
Wood Trait ◽  
Trait Convergence

ABSTRACTCommunity assembly processes, environmental filtering and limiting similarity, determine functional traits values within communities. Because environment influences the number of viable functional strategies species might take, a strong effect of environmental filter often results in communities having species with similar trait values and narrow functional niches. On the other hand, limiting similarity lead to communities with broader functional spaces. The degree to community assembly processes influence wood trait variation has important implications for paleoclimate estimation using fossil wood since the main tenet of the approach is environmental driven trait convergence, and assumes a central role of environmental filtering. We used functional diversity (FD) to determine how three wood anatomical traits vary in 14 extant communities (272 species) growing under different climate regimes, and inferred the prevalence of environmental filtering/limiting similarity. We also calculated FD metrics for the El Cien Formation fossil woods and discussed the results in light of the current knowledge of the flora. We found lower anatomical diversity in communities growing in dry/cool places (smaller functional spaces and lower abundance of trait combinations), suggesting that strong wood anatomical trait convergence could be the result of stronger habitat filtering in these communities. A lower strength of environmental filter in warm/wet environments, likely results in an amplification of the role of other drivers that promote higher number of hydraulic strategies through niche partition in highly structured communities. More complex ecological structures in mild tropical places likely lead to a higher spread of wood trait values. This asymmetry in the strength of environmental filter along climate gradients, suggest that the imbalances in strength of the trait-climate convergence, should be incorporated in paleoclimate prediction models. FD approach can be used to recognize promising traits with narrow niches along climate gradients, and therefore a constant effect of environmental filter.

scholarly journals Trait-based community assembly of epiphytic diatoms in saline astatic ponds: a test of the stress-dominance hypothesis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Éva Ács ◽  
Angéla Földi ◽  
Csaba Ferenc Vad ◽  
Zsuzsa Trábert ◽  
Keve Tihamér Kiss ◽  
...  
Keyword(s):  
Functional Diversity ◽  
Community Assembly ◽  
Environmental Gradients ◽  
N Uptake ◽  
Environmental Filtering ◽  
Limiting Similarity ◽  
Epiphytic Diatoms ◽  
Assembly Rule ◽  
Trait Convergence ◽  
Diatom Communities

Abstract The stress dominance hypothesis (SDH) postulates that strong environmental gradients drive trait convergence in communities over limiting similarity. Previous studies, conducted mostly with terrestrial plant communities, found controversial evidence for this prediction. We provide here the first test for SDH for epiphytic diatoms. We studied community assembly in diatom communities of astatic ponds. These water bodies serve as a good model system for testing SDH because they exhibit stress gradients of various environmental factors. Functional diversity of diatom communities was assessed based on four traits: (1) combined trait reflecting the trade-off between stress tolerance and competitive dominance, (2) cell size, (3) oxygen requirement and (4) N-uptake strategy. According to our results, salinity, pH and the width of the macrophyte belt appeared as significant predictors of the trait convergence/divergence patterns presumably acting through influencing the availability of carbon dioxide and turbidity. Lower trait diversity was found in turbid, more saline and more alkaline ponds and functional diversity was higher in transparent, less saline and less alkaline ponds. Overall, our results supported the stress dominance hypothesis. In habitats representing increased environmental stress, environmental filtering was the most important community assembly rule, while limiting similarity became dominant under more favourable conditions.

scholarly journals Trait convergence and trait divergence in lake phytoplankton reflect community assembly rules

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Gábor Borics ◽  
Viktória B-Béres ◽  
István Bácsi ◽  
Balázs A. Lukács ◽  
E. T-Krasznai ◽  
...  
Keyword(s):  
Environmental Stress ◽  
Community Assembly ◽  
Environmental Gradients ◽  
Environmental Filtering ◽  
Limiting Similarity ◽  
Relative Importance ◽  
Trait Divergence ◽  
Phytoplankton Communities ◽  
Trait Convergence ◽  
Phytoplankton Traits

Abstract Environmental filtering and limiting similarity are those locally acting processes that influence community structure. These mechanisms acting on the traits of species result in trait convergence or divergence within the communities. The role of these processes might change along environmental gradients, and it has been conceptualised in the stress-dominance hypothesis, which predicts that the relative importance of environmental filtering increases and competition decreases with increasing environmental stress. Analysing trait convergence and divergence in lake phytoplankton assemblages, we studied how the concepts of ‘limiting similarity’ versus ‘environmental filtering’ can be applied to these microscopic aquatic communities, and how they support or contradict the stress-dominance hypothesis. Using a null model approach, we investigated the divergence and convergence of phytoplankton traits along environmental gradients represented by canonical axes of an RDA. We used Rao’s quadratic entropy as a measure of functional diversity and calculated effect size (ES) values for each sample. Negative ES values refer to trait convergence, i.e., to the higher probability of the environmental filtering in community assembly, while positive values indicate trait divergence, stressing the importance of limiting similarity (niche partitioning), that is, the competition between the phytoplankters. Our results revealed that limiting similarity and environmental filtering may operate simultaneously in phytoplankton communities, but these assembly mechanisms influenced the distribution of phytoplankton traits differently, and the effects show considerable changes along with the studied scales. Studying the changes of ES values along with the various scales, our results partly supported the stress-dominance hypothesis, which predicts that the relative importance of environmental filtering increases and competition decreases with increasing environmental stress.

scholarly journals Co-occurrences of tropical trees in eastern South America: disentangling abiotic and biotic forces

Plant Ecology ◽  
2021 ◽  
Author(s):  
Emma-Liina Marjakangas ◽  
Otso Ovaskainen ◽  
Nerea Abrego ◽  
Vidar Grøtan ◽  
Alexandre A. de Oliveira ◽  
...  
Keyword(s):  
South America ◽  
Tree Species ◽  
Large Scale ◽  
Environmental Filtering ◽  
Limiting Similarity ◽  
Phylogenetic Relatedness ◽  
Biogeographical Regions ◽  
Dependent Processes ◽  
Occurrence Of Species

AbstractSpecies co-occurrences in local communities can arise independent or dependent on species’ niches. However, the role of niche-dependent processes has not been thoroughly deciphered when generalized to biogeographical scales, probably due to combined shortcomings of data and methodology. Here, we explored the influence of environmental filtering and limiting similarity, as well as biogeographical processes that relate to the assembly of species’ communities and co-occurrences. We modelled jointly the occurrences and co-occurrences of 1016 tropical tree species with abundance data from inventories of 574 localities in eastern South America. We estimated species co-occurrences as raw and residual associations with models that excluded and included the environmental effects on the species’ co-occurrences, respectively. Raw associations indicate co-occurrence of species, whereas residual associations indicate co-occurrence of species after accounting for shared responses to environment. Generally, the influence of environmental filtering exceeded that of limiting similarity in shaping species’ co-occurrences. The number of raw associations was generally higher than that of the residual associations due to the shared responses of tree species to the environmental covariates. Contrary to what was expected from assuming limiting similarity, phylogenetic relatedness or functional similarity did not limit tree co-occurrences. The proportions of positive and negative residual associations varied greatly across the study area, and we found a significant tendency of some biogeographical regions having higher proportions of negative associations between them, suggesting that large-scale biogeographical processes limit the establishment of trees and consequently their co-occurrences.

scholarly journals Distinguishing the signatures of local environmental filtering and regional trait range limits in the study of trait-environment relationships

2019 ◽  
Author(s):  
Pierre Denelle ◽  
Cyrille Violle ◽  
François Munoz
Keyword(s):  
Community Assembly ◽  
Environmental Gradients ◽  
Boundary Effect ◽  
Extreme Environments ◽  
Environmental Filtering ◽  
Range Limits ◽  
Species Pool ◽  
Statistical Tool ◽  
Leaf Trait ◽  
Trait Convergence

AbstractUnderstanding the imprint of environmental filtering on community assembly along environmental gradients is a key objective of trait-gradient analyses. Depending on local constraints, this filtering generally entails that species departing from an optimum trait value have lower abundances in the community. The Community-Weighted Mean (CWM) and Variance (CWV) of trait values are then expected to depict the optimum and intensity of filtering, respectively. However, the trait distribution within the regional species pool and its limits can also affect local CWM and CWV values apart from the effect of environmental filtering. The regional trait range limits are more likely to be reached in communities at the extremes of environmental gradients. Analogous to the mid-domain effect in biogeography, decreasing CWV values in extreme environments can then represent the influence of regional trait range limits rather than stronger filtering in the local environment. We name this effect the “Trait-Gradient Boundary Effect” (TGBE). First, we use a community assembly framework to build simulated communities along a gradient from a species pool and environmental filtering with either constant or varying intensity while accounting for immigration processes. We demonstrate the significant influence of TGBE, in parallel to environmental filtering, on CWM and CWV at the extremes of the environmental gradient. We provide a statistical tool based on Approximate Bayesian Computation to decipher the respective influence of local environmental filtering and regional trait range limits. Second, as a case study, we reanalyze the functional composition of alpine plant communities distributed along a gradient of snow cover duration. We show that leaf trait convergence found in communities at the extremes of the gradient reflect an influence of trait range limits rather than stronger environmental filtering. These findings challenge correlative trait-environment relationships and call for more explicitly identifying the mechanisms responsible of trait convergence/divergence along environmental gradients.

scholarly journals Environmental Filtering Influences Functional Community Assembly of Epibenthic Communities

2021 ◽  
Vol 8 ◽  
Author(s):  
Lauren Sutton ◽  
Franz J. Mueter ◽  
Bodil A. Bluhm ◽  
Katrin Iken
Keyword(s):  
Community Assembly ◽  
Chukchi Sea ◽  
Environmental Filtering ◽  
Biotic Interactions ◽  
Beaufort Sea ◽  
Functional Trait ◽  
Functional Community ◽  
Trait Convergence ◽  
High Trait ◽  
Epibenthic Communities

Community assembly theory states that species assemble non-randomly as a result of dispersal limitation, biotic interactions, and environmental filtering. Strong environmental filtering likely leads to local assemblages that are similar in their functional trait composition (high trait convergence) while functional trait composition will be less similar (high trait divergence) under weaker environmental filters. We used two Arctic shelves as case studies to examine the relationship between functional community assembly and environmental filtering using the geographically close but functionally and environmentally dissimilar epibenthic communities on the Chukchi and Beaufort Sea shelves. Environmental drivers were compared to functional trait composition and to trait convergence within each shelf. Functional composition in the Chukchi Sea was more strongly correlated with environmental gradients compared to the Beaufort Sea, as shown by a combination of RLQ and fourth corner analyses and community-weighted mean redundancy analyses. In the Chukchi Sea, epibenthic functional composition, particularly body size, reproductive strategy, and several behavioral traits (i.e., feeding habit, living habit, movement), was most strongly related to gradients in percent mud and temperature while body size and larval development were most strongly related to a depth gradient in the Beaufort Sea. The stronger environmental filter in the Chukchi Sea also supported the hypothesized relationship with higher trait convergence, although this relationship was only evident at one end of the observed environmental gradient. Strong environmental filtering generally provides a challenge for biota and can be a barrier for invading species, a growing concern for the Chukchi Sea shelf communities under warming conditions. Weaker environmental filtering, such as on the Beaufort Sea shelf, generally leads to communities that are more structured by biotic interactions, and possibly representing partitioning of resources among species from intermediate disturbance levels. We provide evidence that environmental filtering can structure functional community composition, providing a baseline of how community function could be affected by stressors such as changes in environmental conditions or increased anthropogenic disturbance.

α and β diversity of fishes in relation to a gradient of habitat structural complexity supports the role of environmental filtering in community assembly

2019 ◽  
Vol 81 (2) ◽  
Author(s):  
Eduardo R. Cunha ◽  
Kirk O. Winemiller ◽  
João C. B. da Silva ◽  
Taise M. Lopes ◽  
Luiz C. Gomes ◽  
...  
Keyword(s):  
Community Assembly ◽  
Environmental Filtering ◽  
Structural Complexity ◽  
Β Diversity

scholarly journals Functional diversity of reproductive traits increases across succession in the Atlantic forest

Rodriguésia ◽  
2016 ◽  
Vol 67 (2) ◽  
pp. 321-333 ◽  
Author(s):  
Bianca Warring ◽  
Fernanda Cristina Gil Cardoso ◽  
Marcia C.M. Marques ◽  
Isabela Galarda Varassin
Keyword(s):  
Functional Diversity ◽  
Atlantic Forest ◽  
Forest Succession ◽  
Biotic Interactions ◽  
Reproductive Traits ◽  
Limiting Similarity ◽  
Trait Distribution ◽  
Functional Richness ◽  
Functional Dispersion

Abstract Niche and neutral processes shape community assembly with a possible shift of niche and neutral importance in communities undergoing temporal changes during succession. Functional diversity helps to discriminate assembly processes since trait distribution is dependent on those processes. We evaluated the changes in reproductive traits related to pollination and seed dispersal in a successional gradient in an Atlantic Forest area, Southern Brazil. We surveyed forests undergoing regeneration varying in age from 2 to 80 years after pasture abandonment. We expected an increase in functional diversity of reproductive traits and a greater role of limiting similarity across succession. Abiotic and mixed pollination systems, dioecious sexual system, biotic dispersed, many-seeded and small-seeded species decreased as the forest got older. Conversely, bee-pollinated, bell-shaped, small and androgynous flowers increased across forest succession as well biotic dispersed and large-seeded species. Functional richness and functional dispersion were higher in older forests. Changes in functional diversity were positively related to species richness, indicating that species enrichment in older forests added new sets of reproductive traits. These changes in trait distribution and functional diversity across succession in the Atlantic Forest suggest an increased role of biotic interactions and limiting similarity process structuring plant assemblages of second-growth tropical forests.

scholarly journals Community assembly mechanisms and succession processes significantly differ among treatments during the restoration of Stipa grandis – Leymus chinensis communities

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ke Dong ◽  
Guang Hao ◽  
Nan Yang ◽  
Jian-li Zhang ◽  
Xin-feng Ding ◽  
...  
Keyword(s):  
Community Assembly ◽  
Community Dynamics ◽  
Functional Divergence ◽  
Environmental Filtering ◽  
Leymus Chinensis ◽  
Grassland Restoration ◽  
Limiting Similarity ◽  
Niche Theory ◽  
Functional Richness ◽  
Semi Arid

Abstract Understanding community assembly mechanisms is helpful to predict community dynamics. To explore which community assembly mechanism(s) drive(s) the grassland restoration in semi-arid region, we investigated the relationships between plant trait and species relative abundance (SRA), and estimated community functional diversity indices for each community under different treatments (enclosure, grazing and mowing treatment) in a restoration region of Stipa grandis – Leymus chinensis communities in the northern China from 2010 to 2012. There was a high fraction of significant relationships between trait value and SRA, suggesting that niche theory structured the grassland restoration in this region. The functional richness was higher and the functional divergence was lower in the enclosure community than that in the grazing or mowing community, and significantly positive plant height - SRA relationship was found in the enclosure community. These findings demonstrated that limiting similarity based on niche theory was more important in structuring the enclosure community and that environmental filtering based on niche theory played a more important role in driving the grazing or mowing community. Only the factor of year significantly affected the functional evenness (FEve), and the lowest FEve in 2011 implied that the relatively lower precipitation could enhance the effect of limiting similarity on community assembly in the semi-arid grassland.

scholarly journals Advances, challenges and a developing synthesis of ecological community assembly theory

2011 ◽  
Vol 366 (1576) ◽  
pp. 2403-2413 ◽  
Author(s):  
Evan Weiher ◽  
Deborah Freund ◽  
Tyler Bunton ◽  
Artur Stefanski ◽  
Tali Lee ◽  
...  
Keyword(s):  
Community Assembly ◽  
Common Ground ◽  
Environmental Gradients ◽  
Environmental Filtering ◽  
Relative Importance ◽  
Species Sorting ◽  
Neutral Processes ◽  
Multiple Processes ◽  
Niche Assembly

Ecological approaches to community assembly have emphasized the interplay between neutral processes, niche-based environmental filtering and niche-based species sorting in an interactive milieu. Recently, progress has been made in terms of aligning our vocabulary with conceptual advances, assessing how trait-based community functional parameters differ from neutral expectation and assessing how traits vary along environmental gradients. Experiments have confirmed the influence of these processes on assembly and have addressed the role of dispersal in shaping local assemblages. Community phylogenetics has forged common ground between ecologists and biogeographers, but it is not a proxy for trait-based approaches. Community assembly theory is in need of a comparative synthesis that addresses how the relative importance of niche and neutral processes varies among taxa, along environmental gradients, and across scales. Towards that goal, we suggest a set of traits that probably confer increasing community neutrality and regionality and review the influences of stress, disturbance and scale on the importance of niche assembly. We advocate increasing the complexity of experiments in order to assess the relative importance of multiple processes. As an example, we provide evidence that dispersal, niche processes and trait interdependencies have about equal influence on trait-based assembly in an experimental grassland.

Sign in / Sign up

Export Citation Format

Share Document