Search results for "Community dynamics"
showing 10 items of 13 documents
Effects of the temporal scale of observation on the analysis of aquatic invertebrate metacommunities
2020
The development of metacommunity theory has boosted the implementation of numerous empirical tests with field data, mostly focused on the role of spatial and environmental gradients on metacommunity organization. These studies showed an important dependence of the results on the observational scale considered, i.e., spatial grain, sampling spacing, and extent. However, few works deal with time per se as a component explaining metacommunity structure, even when data from periodic sampling are available. We suggest adding time explicitly to metacommunity analysis, but taking into account that the temporal scale of observation could affect the estimation of the relative influence of environmen…
Eco‐evolutionary dynamics driven by fishing : from single species models to dynamic evolution within complex food webs
2020
Evidence of contemporary evolution across ecological time scales stimulated research on the eco‐evolutionary dynamics of natural populations. Aquatic systems provide a good setting to study eco‐evolutionary dynamics owing to a wealth of long‐term monitoring data and the detected trends in fish life‐history traits across intensively harvested marine and freshwater systems. In the present study, we focus on modelling approaches to simulate eco‐evolutionary dynamics of fishes and their ecosystems. Firstly, we review the development of modelling from single‐species to multispecies approaches. Secondly, we advance the current state‐of‐the‐art methodology by implementing evolution of life‐history…
Dynamics of small-mammal communities along an elevational gradient
2019
Elevation is one of the most important natural gradients that is strongly shaping communities across relatively small areas. However, few studies have followed the temporal dynamics of elevational patterns, even in organisms for which population and community fluctuations have been extensively studied, such as rodents. Here we report the multiannual dynamics of small-mammal communities along an elevational gradient in the Southern Carpathians. During a 5-year survey, we conducted live-trapping in forested and shrubby habitats, at elevations between 820 and 2040 m. We used partial constrained multivariate analysis and mixed-effects models to test the effect of elevation, year, and their int…
A modified niche model for generating food webs with stage‐structured consumers: The stabilizing effects of life‐history stages on complex food webs
2021
Abstract Almost all organisms grow in size during their lifetime and switch diets, trophic positions, and interacting partners as they grow. Such ontogenetic development introduces life‐history stages and flows of biomass between the stages through growth and reproduction. However, current research on complex food webs rarely considers life‐history stages. The few previously proposed methods do not take full advantage of the existing food web structural models that can produce realistic food web topologies.We extended the niche model developed by Williams and Martinez (Nature, 2000, 404, 180–183) to generate food webs that included trophic species with a life‐history stage structure. Our me…
What Are the Success Factors of Multilingual Families? Relationships Between Linguistic Attitudes and Community Dynamics
2021
The research focuses on the influence of emotional, cognitive, and social climate on the language choices of multilingual families, and the impact they can have on their general well-being, intergenerational relationships, and the community context. The methodological framework of reference is Grounded Theory. Collected data concern language practices, attitudes, emotions, and generational, trigenerational, and social interactive dynamics of multilingual families. The results include key insights into the variables underlying the linguistic attitudes of multicultural families. Two Network Views suggest that linguistic attitudes, such as the conscious management of specific and complex dynam…
BioTIME: A database of biodiversity time series for the Anthropocene
2018
Abstract Motivation The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community-led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene. Main types of variables included The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, th…
Impacts of piscicide-induced fish removal on resource use and trophic diversity of lake invertebrates
2022
Chemical eradication of non-native species has become a widely used method to mitigate the potential negative im- pacts of altered competitive or predatory dynamics on biodiversity and natural ecosystem processes. However, the re- sponses of non-target species can vary from rapid full recovery to delayed or absent recolonization, and little is known about the potential shifts in resource use and trophic diversity of native species following chemical treatments. We used a before-after-control-impact approach to study the effects of rotenone piscicide treatment on abundance and tro- phic niche of benthic invertebrates in three untreated and three treated lakes in central Norway, the latter gr…
Zooplankton biodiversity and community structure vary along spatiotemporal environmental gradients in restored peridunal ponds
2015
<p>Zooplankton assemblages in neighboring ponds can show important spatial and temporal heterogeneity. Disentangling the influence of regional versus local factors, and of deterministic versus stochastic processes has been recently highlighted in the context of the metacommunity theory. In this study, we determined patterns of temporal and spatial variation in zooplankton diversity along one hydrological year in restored ponds of different hydroperiod and age. The following hypotheses regarding the assembling of species over time were tested: i) dispersal is not limited in our study system due to its small area and high exposure to dispersal vectors; ii) community dissimilarity among …
Impact of wheat straw decomposition on successional patterns of soil microbial community structure
2009
International audience; The dynamics of indigenous bacterial and fungal soil communities were followed throughout the decomposition of wheat straw residue. More precisely, such dynamics were investigated in the different soil zones under the influence of decomposing wheat straw residue (i.e. residues, soil adjacent to residue = detritusphere, and bulk soil). The genetic structures of bacterial and fungal communities were compared throughout the decomposition process long by applying B- and F-ARISA (for bacterial and fungal-automated ribosomal intergenic spacer analysis) to DNA extracts from these different zones. Residue decomposition induced significant changes in bacterial and fungal comm…
Relative role of fish vs. starfish predation in controlling sea urchin populations in Mediterranean rocky shores
2009
In the Mediterranean, fishing bans generally allow the recovery of populations of sea urchin predators, such as the seabreams Diplodus sargus and D. vulgaris, promoting the transformation of overgrazed communities into ones dominated by erect macroalgae. However, in the marine reserve on Ustica Island (SW Italy) the opposite trend has occurred in the upper infralittoral community, and urchin barrens formed after the cessation of fishing activities. We hypothesized that (1) the natural scarcity of the 2 seabream species leads to a low predation rate on sea urchins at Ustica, and (2) predation rate varies with depth, due to differences in the predator assemblages. Tethering experiments were c…