scholarly journals Compensatory responses can alter the form of the biodiversity–function relation curve

2019 ◽  
Vol 286 (1901) ◽  
pp. 20190287 ◽  
Author(s):  
Matthias S. Thomsen ◽  
Jasmin A. Godbold ◽  
Clement Garcia ◽  
Stefan G. Bolam ◽  
Ruth Parker ◽  
...  
Keyword(s):  
Community Composition ◽  
Ecosystem Functioning ◽  
Species Interactions ◽  
Practical Application ◽  
Compensatory Mechanisms ◽  
Ecosystem Properties ◽  
Compensatory Responses ◽  
Composition And Structure ◽  
Dominance Structure ◽  
The Stability

There is now strong evidence that ecosystem properties are influenced by alterations in biodiversity. The consensus that has emerged from over two decades of research is that the form of the biodiversity–functioning relationship follows a saturating curve. However, the foundation from which these conclusions are drawn mostly stems from empirical investigations that have not accounted for post-extinction changes in community composition and structure, or how surviving species respond to new circumstances and modify their contribution to functioning. Here, we use marine sediment-dwelling invertebrate communities to experimentally assess whether post-extinction compensatory mechanisms (simulated by increasing species biomass) have the potential to alter biodiversity–ecosystem function relations. Consistent with recent numerical simulations, we find that the form of the biodiversity–function curve is dependent on whether or not compensatory responses are present, the cause and extent of extinction, and species density. When species losses are combined with the compensatory responses of surviving species, both community composition, dominance structure, and the pool and relative expression of functionally important traits change and affect species interactions and behaviour. These observations emphasize the importance of post-extinction community composition in determining the stability of ecosystem functioning following extinction. Our results caution against the use of the generalized biodiversity–function curve when generating probabilistic estimates of post-extinction ecosystem properties for practical application.

scholarly journals Benthic estuarine communities' contribution to bioturbation under the experimental effect of marine heatwaves

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Dolbeth ◽  
O. Babe ◽  
D. A. Costa ◽  
A. P. Mucha ◽  
P. G. Cardoso ◽  
...  
Keyword(s):  
Community Composition ◽  
Ecosystem Functioning ◽  
Structural Changes ◽  
Nutrient Release ◽  
Biological Communities ◽  
Thermal Change ◽  
Composition And Structure ◽  
Temperature Ranges ◽  
Negative Impacts ◽  
Heat Extremes

AbstractMarine heatwaves are increasing worldwide, with several negative impacts on biological communities and ecosystems. This 24-day study tested heatwaves' effect with distinct duration and recovery periods on benthic estuarine communities' diversity and contribution to ecosystem functioning experimentally. The communities were obtained from a temperate estuary, usually subjected to high daily thermal amplitudes. Our goal was to understand the communities' response to the thermal change, including the community descriptors and behavioural changes expected during heat extremes. We measured community composition and structural changes and the bioturbation process and nutrient release as ecosystem functioning measurements. Overall, our findings highlight the potential tolerance of studied estuarine species to the temperature ranges tested in the study, as community composition and structure were similar, independently of the warming effect. We detected a slight trend for bioturbation and nutrient release increase in the communities under warming, yet these responses were not consistent with the heatwaves exposure duration. Overall, we conclude on the complexity of estuarine communities’ contribution to functioning under warming, and the importance of scalable experiments with benthic organisms' responses to climate variability, accommodating longer time scales and replication. Such an approach would set more efficient expectations towards climate change mitigation or adaptation in temperate estuarine ecosystems.

Community Dynamics and Stability

2013 ◽  
Author(s):  
Eric Post
Keyword(s):  
Community Composition ◽  
Species Interactions ◽  
Community Dynamics ◽  
Species Coexistence ◽  
Environmental Variability ◽  
Climatic Variability ◽  
Self Regulation ◽  
Community Stability ◽  
Biological Communities ◽  
The Stability

This chapter explores the implications of climate change for community composition, dynamics, and stability. It also looks at further examples in which climatic variability mediates interactions among species, in some cases degrading community stability and in other cases promoting it. Ecological theory offers contrasting predictions regarding the consequences for species coexistence and community stability of environmental variability. For instance, short-term instabilities in community composition owing to, for example, high-frequency environmental disturbance may promote the long-term coexistence of species by preventing competitive exclusion of one species by another. Other work suggests, however, that the stability of biological communities in stochastic environments is only possible if there is sufficiently strong self-regulation at one or more trophic levels, or if self-regulation is strong while species interactions are weak, because environmental erosion of population stability at one trophic level may contribute to instability of the community as a whole.

scholarly journals Earthworms drastically change fungal and bacterial communities during vermicomposting of sewage sludge

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jorge Domínguez ◽  
Manuel Aira ◽  
Keith A. Crandall ◽  
Marcos Pérez-Losada
Keyword(s):  
Sewage Sludge ◽  
Community Composition ◽  
Fungal Community ◽  
High Throughput Sequencing ◽  
Wastewater Treatment Plants ◽  
Agricultural Practices ◽  
Fungal Community Composition ◽  
Earthworm Casts ◽  
Composition And Structure ◽  
Sustainable Agricultural Practices

AbstractWastewater treatment plants produce hundreds of million tons of sewage sludge every year all over the world. Vermicomposting is well established worldwide and has been successful at processing sewage sludge, which can contribute to alleviate the severe environmental problems caused by its disposal. Here, we utilized 16S and ITS rRNA high-throughput sequencing to characterize bacterial and fungal community composition and structure during the gut- and cast-associated processes (GAP and CAP, respectively) of vermicomposting of sewage sludge. Bacterial and fungal communities of earthworm casts were mainly composed of microbial taxa not found in the sewage sludge; thus most of the bacterial (96%) and fungal (91%) taxa in the sewage sludge were eliminated during vermicomposting, mainly through the GAP. Upon completion of GAP and during CAP, modified microbial communities undergo a succession process leading to more diverse microbiotas than those found in sewage sludge. Consequently, bacterial and fungal community composition changed significantly during vermicomposting. Vermicomposting of sewage resulted in a stable and rich microbial community with potential biostimulant properties that may aid plant growth. Our results support the use of vermicompost derived from sewage sludge for sustainable agricultural practices, if heavy metals or other pollutants are under legislation limits or adequately treated.

scholarly journals Inhibition or Facilitation? Contrasted Inter-Specific Interactions in Sphagnum under Laboratory and Field Conditions

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1554
Author(s):  
Chao Liu ◽  
Zhao-Jun Bu ◽  
Azim Mallik ◽  
Yong-Da Chen ◽  
Xue-Feng Hu ◽  
...  
Keyword(s):  
Field Experiment ◽  
Species Interactions ◽  
Laboratory Experiments ◽  
Resource Competition ◽  
Specific Interactions ◽  
Interaction Type ◽  
Negative Effects ◽  
Experiment Data ◽  
The Stability ◽  
Positive Effect

In a natural environment, plants usually interact with their neighbors predominantly through resource competition, allelopathy, and facilitation. The occurrence of the positive effect of allelopathy between peat mosses (Sphagnum L.) is rare, but it has been observed in a field experiment. It is unclear whether the stability of the water table level in peat induces positive vs. negative effects of allelopathy and how that is related to phenolic allelochemical production in Sphagnum. Based on field experiment data, we established a laboratory experiment with three neighborhood treatments to measure inter-specific interactions between Sphagnum angustifolium (Russ.) C. Jens and Sphagnum magellanicum Brid. We found that the two species were strongly suppressed by the allelopathic effects of each other. S. magellanicum allelopathically facilitated S. angustifolium in the field but inhibited it in the laboratory, and relative allelopathy intensity appeared to be positively related to the content of released phenolics. We conclude that the interaction type and intensity between plants are dependent on environmental conditions. The concentration of phenolics alone may not explain the type and relative intensity of allelopathy. Carefully designed combined field and laboratory experiments are necessary to reveal the mechanism of species interactions in natural communities.

The Application of Bayesian Statistics in Calculating Project Buffer

2011 ◽  
Vol 58-60 ◽  
pp. 1018-1024
Author(s):  
Feng Ye ◽  
Gui Chen Xu ◽  
Di Kang Zhu
Keyword(s):  
Bayesian Statistics ◽  
Statistical Approach ◽  
Implementation Process ◽  
Current Method ◽  
Practical Application ◽  
Great Flexibility ◽  
Crystal Ball ◽  
Simulation Results ◽  
The Stability

This paper reviews several current methods of calculating buffer on the basis of pointing out each merits and pitfalls and then introduces Bayesian statistical approach to CCS / BM domain to calculate the size of the project buffer, to overcome that the current method of the buffer calculation is too subjective and the defect on lacking of practical application. In Crystal Ball, we compare the simulation results of implementation process on the benchmark of C&PM, RESM and SM. The results show that the buffer using this method can ensure the stability of the project’s completion probability, and this method has great flexibility.

scholarly journals Spiking Neural Network with Linear Computational Complexity for Waveform Analysis in Amperometry

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3276
Author(s):  
Szymon Szczęsny ◽  
Damian Huderek ◽  
Łukasz Przyborowski
Keyword(s):  
Neural Network ◽  
Learning Algorithm ◽  
Waveform Analysis ◽  
Spiking Neural Network ◽  
Synaptic Connections ◽  
Practical Application ◽  
Accuracy Parameter ◽  
The Stability ◽  
Time Waveform ◽  
Network Mapping

The paper describes the architecture of a Spiking Neural Network (SNN) for time waveform analyses using edge computing. The network model was based on the principles of preprocessing signals in the diencephalon and using tonic spiking and inhibition-induced spiking models typical for the thalamus area. The research focused on a significant reduction of the complexity of the SNN algorithm by eliminating most synaptic connections and ensuring zero dispersion of weight values concerning connections between neuron layers. The paper describes a network mapping and learning algorithm, in which the number of variables in the learning process is linearly dependent on the size of the patterns. The works included testing the stability of the accuracy parameter for various network sizes. The described approach used the ability of spiking neurons to process currents of less than 100 pA, typical of amperometric techniques. An example of a practical application is an analysis of vesicle fusion signals using an amperometric system based on Carbon NanoTube (CNT) sensors. The paper concludes with a discussion of the costs of implementing the network as a semiconductor structure.

Effect of Artificial Grassland Establishing on the Vegetation Restoration in the Degraded Ecosystem

2014 ◽  
Vol 955-959 ◽  
pp. 3474-3478
Author(s):  
Tie Jun Sun
Keyword(s):  
Species Diversity ◽  
Community Composition ◽  
Early Period ◽  
Vegetation Restoration ◽  
Bromus Inermis ◽  
Perennial Grasses ◽  
Species Number ◽  
Composition And Structure ◽  
Degraded Ecosystem ◽  
Annual Grasses

Experiment was executed to plant Bromus inermis artificially in the degraded ecosystem, and study effect of grass planting on vegetation restoration. The results indicated that natural vegetation restored rapidly in the degraded ecosystem in two years after grass planted. But species diversity changed little in the early period of vegetation restoration, while vegetation biomass, coverage and anti-interference improved quickly. In addition, species number and important value of perennial grasses increased while those of annual grasses decreased. Then community composition with annual plants mainly changed gradually into that with perennial plants mainly after Bromus inermis planted. However, overground biomass and coverage of restored vegetation and dominance of Bromus inermis planted decreased after vegetation cut once a year. And species diversity and important value of annual grasses increased. Thus it could be good for uniformity of species distribution and stability of community composition and structure to develop.

scholarly journals ­A practical application of reduced-copper antifouling paint in marine biological research

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2213 ◽  
Author(s):  
Andrea S. Jerabek ◽  
Kara R. Wall ◽  
Christopher D. Stallings
Keyword(s):  
Community Composition ◽  
Antifouling Paint ◽  
Biological Research ◽  
Percent Cover ◽  
Practical Application ◽  
Local Effects ◽  
Antifouling Paints ◽  
Manual Removal ◽  
Potential Alternative ◽  
Legislative Changes

Biofouling of experimental cages and other field apparatuses can be problematic for scientists and has traditionally been addressed using frequent manual removal (e.g., scraping, scrubbing). Recent environmental restrictions and legislative changes have driven the development of less hazardous antifouling products, making antifouling paint a potential alternative option to manual removal. Consequently, the viability of using these newly developed products as a replacement for the manual cleaning of exclusion cages was experimentally investigated. There were six treatments tested, comprising three with settlement tiles in experimental cages coated with antifouling paint, two with settlement tiles in unpainted experimental cages, and one cage-free suspended tile. The three antifouling treatments comprised two reduced-copper paints (21% Cu2O and 40% Cu2O) and one copper-free, Econea™-based paint (labeled “ecofriendly”). Antifouling paints were assessed for performance of preventing fouling of the cages and whether they elicited local effects on settlement tiles contained within them. All three paints performed well to reduce fouling of the cages during the initial six weeks of the experiment, but the efficacy of “ecofriendly” paint began to decrease during an extended deployment that lasted 14 weeks. The macro-community composition, biomass, and percent cover of settled organism on tiles within cages treated with copper-based paints (21% and 40% concentrations) were indistinguishable from tiles within the manually scrubbed cages. In contrast, settlement to tiles from the “ecofriendly” treatment was different in composition of macro-community and lower in biomass, suggesting the presence of local effects and therefore rendering it unsuitable for use in settlement experiments. The results of this study suggest that reduced-copper paints have the potential to serve as an alternative to manual maintenance, which may be useful for deployments in locations that are difficult to access on a frequent schedule.

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