scholarly journals Dominance Structure Plays a Leading Role In Shaping Community Stability In The Northern Tibetan Grasslands

2021 ◽  
Author(s):  
Ge Hou ◽  
Peili Shi ◽  
Ning Zong ◽  
Tiancai Zhou ◽  
Minghua Song ◽  
...  
Keyword(s):  
Ecosystem Functioning ◽  
Dominant Species ◽  
Community Dynamics ◽  
Temporal Stability ◽  
Selection Effect ◽  
Community Stability ◽  
Alpine Grasslands ◽  
Leading Role ◽  
Dominance Structure ◽  
Dominant Structure

Abstract Dominant species may strongly influence biotic conditions and interact with other species, and thus are important drivers of community dynamics and ecosystem functioning, particularly in the stressed environment of alpine grasslands. However, the effects of dominant species and its derived dominance structure on the community stability remain poorly understood. We examined the temporal stability of above-ground productivity (2014-2020 year) and biotic stability mechanisms in the Northern Tibetan grasslands with changing species composition and dominance structure along a precipitation gradient. Our results showed that community stability was significantly higher in the alpine meadow than the other types of grasslands. This difference was mainly attributed to higher compensatory effect and selection effect of dominant species in the mesic meadows. Furthermore, dominant structure strongly affected community stability through increasing dominant species stability and species asynchrony. However, species richness had almost little effect. Our findings demonstrate that dominant species, as foundation species, may play leading roles in shaping community stability in the alpine grasslands, highlighting the importance of conserving dominant species for stable ecosystem functioning in these fragile ecosystems under increasing environmental fluctuations.

scholarly journals The more things change, the more they stay the same? When is trait variability important for stability of ecosystem function in a changing environment

2016 ◽  
Vol 371 (1694) ◽  
pp. 20150272 ◽  
Author(s):  
Justin P. Wright ◽  
Gregory M. Ames ◽  
Rachel M. Mitchell
Keyword(s):  
Local Adaptation ◽  
Ecosystem Functioning ◽  
Community Dynamics ◽  
Temporal Stability ◽  
Sufficient Information ◽  
Changing Environment ◽  
Relative Contribution ◽  
Variable Environments ◽  
Intraspecific Trait Variability ◽  
Trait Variability

The importance of intraspecific trait variability for community dynamics and ecosystem functioning has been underappreciated. There are theoretical reasons for predicting that species that differ in intraspecific trait variability will also differ in their effects on ecosystem functioning, particularly in variable environments. We discuss whether species with greater trait variability are likely to exhibit greater temporal stability in their population dynamics, and under which conditions this might lead to stability in ecosystem functioning. Resolving this requires us to consider several questions. First, are species with high levels of variation for one trait equally variable in others? In particular, is variability in response and effects traits typically correlated? Second, what is the relative contribution of local adaptation and phenotypic plasticity to trait variability? If local adaptation dominates, then stability in function requires one of two conditions: (i) individuals of appropriate phenotypes present in the environment at high enough frequencies to allow for populations to respond rapidly to the changing environment, and (ii) high levels of dispersal and gene flow. While we currently lack sufficient information on the causes and distribution of variability in functional traits, filling in these key data gaps should increase our ability to predict how changing biodiversity will alter ecosystem functioning.

scholarly journals Quantifying Community Dynamics of Nitrifiers in Functionally Stable Reactors

2007 ◽  
Vol 74 (1) ◽  
pp. 286-293 ◽  
Author(s):  
Lieven Wittebolle ◽  
Han Vervaeren ◽  
Willy Verstraete ◽  
Nico Boon
Keyword(s):  
Dominant Species ◽  
Municipal Wastewater ◽  
Community Dynamics ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Batch Reactor ◽  
Dominant Role ◽  
Treatment Plant ◽  
Sampling Period ◽  
Rate Of Change ◽  
Municipal Wastewater Treatment

ABSTRACT A sequential batch reactor (SBR) and a membrane bioreactor (MBR) were inoculated with the same sludge from a municipal wastewater treatment plant, supplemented with ammonium, and operated in parallel for 84 days. It was investigated whether the functional stability of the nitrification process corresponded with a static ammonia-oxidizing bacterial (AOB) community. The SBR provided complete nitrification during nearly the whole experimental run, whereas the MBR showed a buildup of 0 to 2 mg nitrite-N liter−1 from day 45 until day 84. Based on the denaturing gradient gel electrophoresis profiles, two novel approaches were introduced to characterize and quantify the community dynamics and interspecies abundance ratios: (i) the rate of change [Δ t (week)] parameter and (ii) the Pareto-Lorenz curve distribution pattern. During the whole sampling period, it was observed that neither of the reactor types maintained a static microbial community and that the SBR evolved more gradually than the MBR, particularly with respect to AOB (i.e., average weekly community changes of 12.6% ± 5.2% for the SBR and 24.6% ± 14.3% for the MBR). Based on the Pareto-Lorenz curves, it was observed that only a small group of AOB species played a numerically dominant role in the nitritation of both reactors, and this was true especially for the MBR. The remaining less dominant species were speculated to constitute a reserve of AOB which can proliferate to replace the dominant species. The value of these parameters in terms of tools to assist the operation of activated-sludge systems is discussed.

scholarly journals Scaling up biodiversity–ecosystem functioning relationships: the role of environmental heterogeneity in space and time

2021 ◽  
Vol 288 (1946) ◽  
pp. 20202779
Author(s):  
Patrick L. Thompson ◽  
Sonia Kéfi ◽  
Yuval R. Zelnik ◽  
Laura E. Dee ◽  
Shaopeng Wang ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Ecosystem Functioning ◽  
Environmental Heterogeneity ◽  
Community Dynamics ◽  
Formal Model ◽  
Spatial Scales ◽  
Scale Dependence ◽  
Space And Time ◽  
Number Of Species

The biodiversity and ecosystem functioning (BEF) relationship is expected to be scale-dependent. The autocorrelation of environmental heterogeneity is hypothesized to explain this scale dependence because it influences how quickly biodiversity accumulates over space or time. However, this link has yet to be demonstrated in a formal model. Here, we use a Lotka–Volterra competition model to simulate community dynamics when environmental conditions vary across either space or time. Species differ in their optimal environmental conditions, which results in turnover in community composition. We vary biodiversity by modelling communities with different sized regional species pools and ask how the amount of biomass per unit area depends on the number of species present, and the spatial or temporal scale at which it is measured. We find that more biodiversity is required to maintain functioning at larger temporal and spatial scales. The number of species required increases quickly when environmental autocorrelation is low, and slowly when autocorrelation is high. Both spatial and temporal environmental heterogeneity lead to scale dependence in BEF, but autocorrelation has larger impacts when environmental change is temporal. These findings show how the biodiversity required to maintain functioning is expected to increase over space and time.

scholarly journals Eulemur , me lemur: the evolution of scent-signal complexity in a primate clade

2012 ◽  
Vol 367 (1597) ◽  
pp. 1909-1922 ◽  
Author(s):  
Javier delBarco-Trillo ◽  
Caitlin R. Sacha ◽  
George R. Dubay ◽  
Christine M. Drea
Keyword(s):  
Dominant Species ◽  
Social Complexity ◽  
Comparative Method ◽  
Principal Component ◽  
Gas Chromatography Mass Spectrometry ◽  
Social Variables ◽  
Chemical Complexity ◽  
Dominance Structure ◽  
Signal Complexity ◽  
Signal Utility

Signal complexity has been linked to social complexity in vocal, but not chemical, communication. To address this gap, we examined the chemical complexity of male and female glandular secretions in eight species of Eulemur. In this diverse clade of macrosmatic primates, species differ by social or mating system and dominance structure. We applied principal component and linear discriminate analyses to data obtained by gas chromatography/mass spectrometry. Beyond the significant effects on chemical signals of gland type, sex, season and species, we found effects of social variables and phylogeny. Notably, female odours were more chemically complex in multimale–multifemale species than pair-bonded species, whereas male odours were more chemically complex in codominant species than female-dominant species. Also, the traditional sexual dimorphism, whereby male signal complexity exceeds that of females, was present in codominant species, but reversed in female-dominant species. Lastly, a positive relationship between the species' pairwise chemical distances and their pairwise phylogenetic distances supported a gradual, but relatively fast mode of signal evolution. We suggest that the comparative method can be a powerful tool in olfactory research, revealing species differences relevant to the understanding of current signal utility and evolutionary processes. In particular, social complexity in lemurs may have selected for olfactory complexity.

Larval fishes of a Middle Atlantic Bight estuary: assemblage structure and temporal stability

1999 ◽  
Vol 56 (2) ◽  
pp. 222-230 ◽  
Author(s):  
David A Witting ◽  
Kenneth W Able ◽  
Michael P Fahay
Keyword(s):  
Continental Shelf ◽  
Dominant Species ◽  
Fish Assemblages ◽  
Larval Fish ◽  
Temporal Stability ◽  
Temperature Cycle ◽  
Sargasso Sea ◽  
Larval Fishes ◽  
Middle Atlantic ◽  
Lower Temperature

We collected weekly, quantitative ichthyoplankton samples over 6 years (1989-1994, 1309 samples) to identify temporal scales of variability in the abundance and occurrence of larval fish assemblages near Little Egg Inlet in southern New Jersey, U.S.A. We collected species that spawn in the estuary (30%), both the estuary and continental shelf (35%), continental shelf (25%), and the Sargasso Sea (10%). The following analyses suggest an annually repeated seasonal progression of species assemblages: (i) the rank abundance of the 20 dominant species did not change significantly from year to year, (ii) variation in the density of the dominant species was primarily explained by intraannual rather than interannual variation, and (iii) multivariate analysis of the assemblage matrix identified five seasonal assemblages that occurred during all six years. We found that the timing and duration of each of these seasonal groups were correlated with two characteristics of the annual temperature cycle, magnitude (higher or lower temperature) and trajectory (increasing vs decreasing temperature). We suggest that the repeated occurrence of larval fish assemblages in temperate estuaries along the U.S. coast may, in part, be driven by local environmental processes.

scholarly journals Dominance structure of assemblages is regulated over a period of rapid environmental change

2018 ◽  
Vol 14 (6) ◽  
pp. 20180187 ◽  
Author(s):  
Faith A. M. Jones ◽  
Anne E. Magurran
Keyword(s):  
Dominant Species ◽  
Meta Analysis ◽  
Environmental Drivers ◽  
Systematic Change ◽  
Ecosystem Responses ◽  
Multiple Components ◽  
Dominance Structure ◽  
Biodiversity Change ◽  
Permutation Models ◽  
Assemblage Size

Ecological assemblages are inherently uneven, with numerically dominant species contributing disproportionately to ecosystem services. Marked biodiversity change due to growing pressures on the world's ecosystems is now well documented. However, the hypothesis that dominant species are becoming relatively more abundant has not been tested. We examined the prediction that the dominance structure of contemporary communities is shifting, using a meta-analysis of 110 assemblage timeseries. Changes in relative and absolute dominance were evaluated with mixed and cyclic-shift permutation models. Our analysis uncovered no evidence of a systematic change in either form of dominance, but established that relative dominance is preserved even when assemblage size (total N ) changes. This suggests that dominance structure is regulated alongside richness and assemblage size, and highlights the importance of investigating multiple components of assemblage diversity when evaluating ecosystem responses to environmental drivers.

scholarly journals Plant community dynamics in shortgrass steppe with grazing relaxation and imposition by large and small herbivores

2011 ◽  
Vol 57 (1-2) ◽  
pp. 23-41 ◽  
Author(s):  
D.G. Milchunas
Keyword(s):  
Body Size ◽  
Dominant Species ◽  
Community Dynamics ◽  
Plant Species Richness ◽  
Sampling Effort ◽  
Large Herbivore ◽  
Large Herbivores ◽  
Plant Richness ◽  
Unique Species

Semiarid rangelands often respond slowly to rest/relaxation of grazing pressure by large herbivores, and the effects of grazing are most often inferred from this direction of study because the imposition of grazing onto previous ungrazed/lightly grazed areas occurred prior to the age of scientific studies. These rangelands host a diversity of small and large herbivores, but grazing studies most often concern effects of the large generalists. Here, the effects of herbivore body size on plant species richness and dominant species, and imposition and relaxation of grazing by large herbivores were studied by opening half of exclosures established in 1939 and building new exclosures to large herbivores, and to small-plus-large herbivores. Plant richness using sensitive species-area sampling was studied in a dry and a wet year, about 62 years after initiating the long-term experiment and about 6-10 years after initiating the altered designs. Convergence of the newly opened to large herbivore grazing treatment to the long-term grazed treatment occurred within 10 years, but convergence of the newly excluded to large herbivore treatment to the long-term excluded treatment had only partly occurred. This indicated that recovery from grazing is slow relative to imposition of grazing by large herbivores, but effects of the additional exclusion of small-plus-large herbivores occurred relatively rapidly. These results were mirrored by trajectories of convergence of the dominant species, and this is discussed with respect to implications for state-and-transition models. Short-term exclusion of small-plus-large herbivores resulted in greater richness than even long-term exclusion of only large herbivores, even though quantities consumed by small herbivores are much less than by large. Grazing effects on plant richness were large in the wet year, but the very dry year suppressed richness on all treatments. When sampling effort and area are the same, the numbers and attributes of species unique to a treatment are indicators of rareness of the richness and traits selected for by the treatment. More unique species were sampled in the small-plus-large herbivore exclosures when comparing body size, and the long-term large herbivore exclosures when comparing time of exclosure. Unique species encountered during sampling the ungrazed treatments were generally forbs, exotic and/or weedy invasive species, and often tall, annual species.

scholarly journals Wild insect diversity increases inter-annual stability in global crop pollinator communities

2021 ◽  
Vol 288 (1947) ◽  
Author(s):  
Deepa Senapathi ◽  
Jochen Fründ ◽  
Matthias Albrecht ◽  
Michael P. D. Garratt ◽  
David Kleijn ◽  
...  
Keyword(s):  
Dominant Species ◽  
Management Practices ◽  
Temporal Stability ◽  
Global Scale ◽  
Agricultural Landscapes ◽  
Crop Pollination ◽  
Ecological Stability ◽  
Pollination Services ◽  
Tropical Regions ◽  
Pollinator Diversity

While an increasing number of studies indicate that the range, diversity and abundance of many wild pollinators has declined, the global area of pollinator-dependent crops has significantly increased over the last few decades. Crop pollination studies to date have mainly focused on either identifying different guilds pollinating various crops, or on factors driving spatial changes and turnover observed in these communities. The mechanisms driving temporal stability for ecosystem functioning and services, however, remain poorly understood. Our study quantifies temporal variability observed in crop pollinators in 21 different crops across multiple years at a global scale. Using data from 43 studies from six continents, we show that (i) higher pollinator diversity confers greater inter-annual stability in pollinator communities, (ii) temporal variation observed in pollinator abundance is primarily driven by the three-most dominant species, and (iii) crops in tropical regions demonstrate higher inter-annual variability in pollinator species richness than crops in temperate regions. We highlight the importance of recognizing wild pollinator diversity in agricultural landscapes to stabilize pollinator persistence across years to protect both biodiversity and crop pollination services. Short-term agricultural management practices aimed at dominant species for stabilizing pollination services need to be considered alongside longer term conservation goals focussed on maintaining and facilitating biodiversity to confer ecological stability.

scholarly journals Diversity and asynchrony in soil microbial communities stabilizes ecosystem functioning

2020 ◽  
Author(s):  
Cameron Wagg ◽  
Yann Hautier ◽  
Sarah Pellkofer ◽  
Samiran Banerjee ◽  
Bernhard Schmid ◽  
...  
Keyword(s):  
Microbial Diversity ◽  
Microbial Communities ◽  
Ecosystem Functioning ◽  
Temporal Dynamics ◽  
Temporal Stability ◽  
Soil Microbial Communities ◽  
Ecosystem Functions ◽  
Soil Microbial Diversity ◽  
Soil Biodiversity ◽  
Soil Microbial

AbstractTheoretical and empirical advances have revealed the importance of biodiversity for stabilizing ecosystem functions through time. Yet despite the global degradation of soils, how the loss of soil microbial diversity can de-stabilizes ecosystem functioning is unknown. Here we experimentally quantified the contribution diversity and the temporal dynamics in the composition of soil microbial communities to the temporal stability of four key ecosystem functions related to nutrient and carbon cycling. Soil microbial diversity loss reduced the temporal stability of all ecosystem functions and was particularly strong when over 50% of microbial taxa were lost. The stabilizing effect of soil biodiversity was linked to asynchrony among microbial taxa whereby different soil fungi and bacteria were associated with different ecosystem functions at different times. Our results emphasize the need to conserve soil biodiversity in order to ensure the reliable provisioning of multiple ecosystems functions that soils provide to society.

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