scholarly journals Exploring Multiple Aspects of Taxonomic and Functional Diversity in Microphytobenthic Communities: Effects of Environmental Gradients and Temporal Changes

2021 ◽  
Vol 12 ◽  
Author(s):  
Anette Teittinen ◽  
Leena Virta
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Functional Diversity ◽  
Environmental Changes ◽  
Environmental Gradients ◽  
Temporal Variations ◽  
The Face ◽  
Functional Dispersion ◽  
Pool System ◽  
Microbial Groups

Biodiversity has traditionally been quantified using taxonomic information but the importance of also considering its functional characteristics has recently gained an increasing attention among microorganisms. However, studies exploring multiple aspects of taxonomic and functional diversity and their temporal variations are scarce for diatoms, which is one of the most important microbial groups in aquatic ecosystems. Here, our aim was to examine the taxonomic and functional alpha and beta diversities of diatoms in a coastal rock pool system characterized by a naturally high environmental heterogeneity. We also investigated the temporal differences in the diversity patterns and drivers. The relationship between the species richness and functional dispersion was temporally coherent, such that species-poor communities tended to be functionally clustered. The trend between the species richness and taxonomic uniqueness of community composition was temporally inconsistent, changing from negative to non-significant over time. Conductivity or distance to the sea or both were key determinants of species richness, functional dispersion, and uniqueness of community composition. The increase of community dissimilarity with an increasing environmental distance was stronger for the taxonomic than the functional composition. Our results suggest that even minor decreases in the species richness may result in a lowered functional diversity and decreased ecosystem functioning. Species-poor ecosystems may, however, have unique species compositions and high contributions to regional biodiversity. Despite changing the species compositions along the environmental gradients, communities may remain to have a high functional similarity and robustness in the face of environmental changes. Our results highlight the advantage of considering multiple biodiversity metrics and incorporating a temporal component for a deeper understanding of the effects of environmental changes on microbial biodiversity.

scholarly journals Treeline ecotones shape the distribution of avian species richness and functional diversity in south temperate mountains

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tomás A. Altamirano ◽  
Devin R. de Zwaan ◽  
José Tomás Ibarra ◽  
Scott Wilson ◽  
Kathy Martin
Keyword(s):  
Species Richness ◽  
Functional Diversity ◽  
Functional Traits ◽  
Habitat Structure ◽  
Environmental Gradients ◽  
Montane Forest ◽  
Avian Species ◽  
Point Counts ◽  
Mountain Habitats ◽  
Elevational Range

Abstract Mountains produce distinct environmental gradients that may constrain or facilitate both the presence of avian species and/or specific combinations of functional traits. We addressed species richness and functional diversity to understand the relative importance of habitat structure and elevation in shaping avian diversity patterns in the south temperate Andes, Chile. During 2010–2018, we conducted 2202 point-counts in four mountain habitats (successional montane forest, old-growth montane forest, subalpine, and alpine) from 211 to 1,768 m in elevation and assembled trait data associated with resource use for each species to estimate species richness and functional diversity and turnover. We detected 74 species. Alpine specialists included 16 species (22%) occurring only above treeline with a mean elevational range of 298 m, while bird communities below treeline (78%) occupied a mean elevational range of 1,081 m. Treeline was an inflection line, above which species composition changed by 91% and there was a greater turnover in functional traits (2–3 times greater than communities below treeline). Alpine birds were almost exclusively migratory, inhabiting a restricted elevational range, and breeding in rock cavities. We conclude that elevation and habitat heterogeneity structure avian trait distributions and community composition, with a diverse ecotonal sub-alpine and a distinct alpine community.

The environmental niche of soil bacterial, archaeal, fungal and protist communities differ along edaphic and topoclimatic gradients in the Alps

2021 ◽  
Author(s):  
Lucie A Malard ◽  
Heidi K Mod ◽  
Nicolas Guex ◽  
Olivier Broennimann ◽  
Erika Yashiro ◽  
...  
Keyword(s):  
Niche Breadth ◽  
Environmental Changes ◽  
Environmental Gradients ◽  
Community Diversity ◽  
Environmental Niche ◽  
Alpha And Beta Diversity ◽  
Niche Concept ◽  
The Alps ◽  
Microbial Groups ◽  
Taxonomic Groups

Abstract BackgroundThe niche concept describes the range of conditions supporting the establishment and persistence of species in the environment. Although widely used in ecology, it has not been often applied to microbes, for which comparative niche analyses are still lacking. Yet, quantifying the niche of microbial taxa is necessary to forecast how taxa and the communities they compose might respond to environmental changes. In this study, we identified important topoclimatic, edaphic, spatial and biotic drivers of the alpha and beta diversity of bacterial, archaeal, fungal and protist communities. Then, we established a method to calculate the niche breadth and position of each taxon along environmental gradients to determine whether microorganisms have distinct environmental niches. ResultsFor all microbial groups, edaphic properties were identified as the most important drivers of both community diversity and composition. Protists presented the largest niche breadths, followed by bacteria and archaea, with fungi displaying the smallest. Niche breadth generally decreased towards environmental extremes, especially along edaphic gradients, suggesting increased specialisation of all microbial taxa in highly selective environments. ConclusionIn this study, we showed that microorganisms have well defined niches, as do macro-organisms, and that these likely drive part of the observed spatial patterns of community variations, but with notable differences among taxonomic groups. Applying the niche concept more widely to microbial ecology should open many novel perspectives, especially to tackle global change challenges.

scholarly journals Changes in taxonomic and functional diversity of plants in a chronosequence of Eucalyptus grandis plantations

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Pamela E. Pairo ◽  
Estela E. Rodriguez ◽  
M. Isabel Bellocq ◽  
Pablo G. Aceñolaza
Keyword(s):  
Species Richness ◽  
Leaf Litter ◽  
Plant Species ◽  
Functional Diversity ◽  
Soil Ph ◽  
Management Practices ◽  
Environmental Changes ◽  
Canopy Cover ◽  
Environmental Drivers ◽  
Natural Grasslands

AbstractTree plantations have become one of the fastest-growing land uses and their impact on biodiversity was evaluated mainly at the taxonomic level. The aim of this study was to analyze environmental changes after the Eucalyptus plantation in an area originally covered by natural grasslands, taking into account the alpha and beta (taxonomic and functional) diversity of plant communities. We selected nine plantation ages, along a 12 years chronosequence, with three replicates per age and three protected grasslands as the original situation. At each replicate, we established three plots to measure plant species cover, diversity and environmental variables. Results showed that species richness, and all diversity indices, significantly declined with increasing plantation age. Canopy cover, soil pH, and leaf litter were the environmental drivers that drove the decrease in taxonomic and functional diversity of plants through the forest chronosequence. Based on the path analyses results, canopy cover had an indirect effect on plant functional diversity, mediated by leaf litter depth, soil pH, and plant species richness. The high dispersal potential, annual, barochorous, and zoochorous plant species were the functional traits more affected by the eucalypt plantations. We recommend two management practices: reducing forest densities to allow higher light input to the understory and, due to the fact that leaf litter was negatively associated with all diversity facets, we recommend reducing their accumulation or generate heterogeneity in its distribution to enhance biodiversity.

scholarly journals The Selective Effects of Environmental Change on the Functional Diversity of Soil Decomposers

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1650
Author(s):  
Herman A. Verhoef
Keyword(s):  
Species Richness ◽  
Functional Diversity ◽  
Resource Use ◽  
Environmental Changes ◽  
Ecosystem Functions ◽  
Soil Organisms ◽  
Soil Biodiversity ◽  
Complementary Resource ◽  
Low Levels ◽  
Facilitative Interactions

Whether decomposition can be affected by the biodiversity of soil organisms is an important question. Biodiversity is commonly expressed through indices that are based on species richness and abundances. Soil processes tend to saturate at low levels of species richness. A component of biodiversity is functional diversity, and we have shown that the absence of the influence of species richness on decomposition switched into a positive relationship between fauna diversity and decomposition when we expressed biodiversity in terms of interspecific functional dissimilarity. Communities with functionally dissimilar species are characterized by complementary resource use and facilitative interactions among species. It is suggested that the effects of environmental changes on ecosystem functions such as decomposition can be better understood if we have more knowledge about the selective effect of these changes on specific facets of soil biodiversity, such as functional diversity.

scholarly journals Lichen Responses to Disturbance: Clues for Biomonitoring Land-use Effects on Riparian Andean Ecosystems

Diversity ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 73 ◽  
Author(s):  
Leiddy Chuquimarca ◽  
Fernando P. Gaona ◽  
Carlos Iñiguez-Armijos ◽  
Ángel Benítez
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Community Composition ◽  
Functional Traits ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Urban Land Use ◽  
Land Use Intensity ◽  
Riparian Ecosystems ◽  
Natural Ecosystems

The transformation of natural ecosystems due to anthropogenic land use is considered one of the main causes of biodiversity loss. Lichens, due to their poikilohydric nature, are very sensitive to natural and anthropogenic disturbances. Therefore, lichen communities have been widely used as bioindicators of climatic and environmental changes. In this study, we evaluated how the species richness and community composition of epiphytic lichens respond to land-use intensity in riparian ecosystems of the Andes in southern Ecuador. Additionally, we evaluate how the richness of six functional traits (photobiont type, growth form, and reproductive strategy) changed across the different land-use intensity. We selected 10 trees in twelve sites for a total de 120 trees, equally divided into four riparian land-use intensities (forest, forest-pasture, pasture and urban). We recorded a total of 140 lichen species. Species richness was highest in the forest sites and decreased towards more anthropogenic land uses. Lichen community composition responded to land-use intensity, and was explained by microclimate variables (e.g., precipitation, percentage forested area) and distance to the forest. Richness of functional traits of lichens also differed significantly among the four land-use intensity and decreased from forests to urban land-use. Taxonomic diversity and functional traits can be effectively applied as bioindicators to assess and monitor the effects of land-use changes in the riparian ecosystems of tropical montane regions.

scholarly journals Dispersal limitation and climate-related environmental gradients structure microcrustacean composition in freshwater lakes, Ellesmere Island, Canada

2008 ◽  
Vol 65 (9) ◽  
pp. 1905-1918 ◽  
Author(s):  
Angela L. Strecker ◽  
Rebecca Milne ◽  
Shelley E. Arnott
Keyword(s):  
Species Richness ◽  
Environmental Change ◽  
Community Composition ◽  
Environmental Gradients ◽  
Negative Relationship ◽  
Ellesmere Island ◽  
Arctic Lakes ◽  
The Arctic ◽  
Arctic Ecosystems ◽  
Daphnia Middendorffiana

Dramatic environmental change is expected in the Arctic, yet little is known about the occurrence and community composition of microcrustaceans in Arctic lakes and how this will be influenced by future environmental change. We sampled and calculated relative abundances of microcrustacean species in 54 lakes on Ellesmere Island, Canada. New species records on Ellesmere Island included Daphnia umbra , Tachidius discipes , and Artemeopsis stefanssoni . Daphnia middendorffiana/tenebrosa was the most common taxon and often dominated microcrustacean assemblages, likely a result of its pigmentation, which offers resistance to ultraviolet radiation. Species richness was positively associated with nutrients, dissolved organic carbon (DOC), temperature, calcium, and conductivity and negatively affected by elevation. In contrast to most findings in temperate systems, we detected a negative relationship between species richness and surface area. Community composition was influenced by DOC, nutrients, and elevation but was also related to spatial variables, suggesting that spatial gradients in environmental conditions and dispersal are important drivers of differences among sites. Arctic ecosystems are expected to change rapidly in the coming years because of climate change and ozone thinning, and we expect that associated changes in DOC, temperature, and nutrients will affect microcrustacean species richness and distribution throughout the landscape.

Modern pollen distributions and their relationship with environmental gradient in Southern Morocco

2021 ◽  
Author(s):  
Sokaina Tadoumant ◽  
Ilham Bouimetarhan ◽  
Martin Koelling ◽  
Asmae Baqloul ◽  
Lhoussaine Bouchaou
Keyword(s):  
Marine Sediment ◽  
Environmental Changes ◽  
Environmental Gradients ◽  
Sediment Cores ◽  
Temporal Variations ◽  
The South ◽  
Aeolian Transport ◽  
Trade Winds ◽  
Modern Pollen ◽  
Pollen And Spores

<p>      Terrestrial signals in marine sediment archives are frequently used for paleoclimate reconstructions. A little is known about the origin of terrestrial components such as pollen and spores, organic and inorganic elements in the sedimentary archives. The aims of this study is to investigate the geographic distribution pattern of pollen and spores in southern Morocco in relation to environmental gradients, and different transport mechanisms in order to link temporal variations in marine sediment cores to environmental changes in southern Morocco. Pollen taxa of Argania spinosa, Cichorioideae, Poaceae and Cyperaceae exhibit high percentages and concentrations in the semi-arid Souss Massa basin and the relatively humid Tensift basin accompanied with higher values of Fe/Ca and Ti/Al. Moreover, the simulation between distribution of Olea/Phillyrea and Ti/Al ratio suggests that Olea/Phillyrea are mainly dispersed by wind transport. However, Artemisia and Quercus distributions are limited to the south of High Atlas and the northern Anti Atlas. Chenopodiaceae, Caryophyllaceae , and Amaranthaceae (CCA) show a maximum percentages in littoral sites especially of Souss and Draa basins according to the important production of pollen quantities, the  high values of CCA from north to south of study area are indicated the starts of Saharan-type climate with increasing values of Acacia, Ziziphus, Asphodelus and Tamarix taxa may indicate plants adaptation to droughts, and/or a dominant aeolian transport. The South of Morocco which is known by higher wind inflows and low rainfall during the year occurring as occasional events during the winter, we conclude that pollen are primarily transported by the NE trade winds and occasionally with rivers in the basins.</p>

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