Search results for " changes"
showing 10 items of 824 documents
Small-scale patches of detritus as habitat for invertebrates within a Zostera noltei meadow
2021
Abstract Seagrass detritus can attract numerous invertebrates as it provides food and substrate within the meadow or in adjacent environments. Nonetheless, several factors could modify the invertebrate response to this habitat. In this study, we tested if epifaunal colonisation of Zostera noltei detritus was related to substrate availability rather than food and whether colonising assemblages were similar according to the meadow structural complexity. Litterbags filled with natural or artificial detritus were deployed within an eelgrass meadow in a Mediterranean coastal lagoon (Thau lagoon, France). Colonisation appeared to be driven by the presence of detritus, with similar assemblages in …
Can vegetation provide indications of ancient lake shorelines after more than one hundred years? A case study of Iskander-kul Lake, Tajikistan
2017
Abstract Bioindication is a common approach to assess and evaluate environmental changes over both short or long periods of time. Here we attempt to highlight that vegetation can provide indications of the palaeoshoreline of Lake Iskander-kul, even after at least 150 years. It is an example of a dammed lake that was created by a huge mass rockfall as a result of a strong earthquake during the late Pleistocene. Applying the two way indicator species analysis (TWINSPAN) we found that the shrubby vegetation is the particular one that can still effectively thrive along the palaeoshoreline despite the lake downlift. Using the phi coefficient as a fidelity measure for certain vegetation type, we …
Global functional variation in alpine vegetation
2021
International audience; Questions. What are the functional trade-offs of vascular plant species in global alpine ecosystems? How is functional variation related to vegetation zones, climatic groups and biogeographic realms? What is the relative contribution of macroclimate and evolutionary history in shaping the functional variation of alpine plant communities? Location. Global. Methods. We compiled a data set of alpine vegetation with 5,532 geo-referenced plots, 1,933 species and six plant functional traits. We used principal component analysis to quantify functional trade-offs among species and trait probability density to assess the functional dissimilarity of alpine vegetation in differ…
New insight into the colonization processes of common voles: inferences from molecular and fossil evidence.
2008
Biologie et Gestion des Populations, Campus International de Baillarguet, Montferrier/Lez, FranceElucidating the colonization processes associated with Quaternary climatic cycles is important in order to understand the distribution of biodiversity and the evolutionary potential of temperate plant and animal species. In Europe, general evolutionary scenarios have been defined from genetic evidence. Recently, these scenarios have been challenged with genetic as well as fossil data. The origins of the modern distributions of most temperate plant and animal species could predate the Last Glacial Maximum. The glacial survival of such populations may have occurred in either southern (Mediterranea…
A conceptual framework for the integral management of marine protected areas
2009
A general conceptual framework for the management of marine protected areas (MPAs) was developed. The driver-pressure-state-impacts-response (DPSIR) framework was used to determine the elements affecting MPAs. The developed evaluation framework helped to select an appropriate suite of indicators to support an ecosystem approach, an assessment of the MPAs functioning and policy decisions. Gaps derived from the management and policy responses in the MPAs were also outlined. It was concluded that the DPSIR framework can help to simplify the complexity of MPA management. This document is a tool for policy makers, scientists and general public on the relevance of indicators to monitor changes an…
Effects of mowing on fungal endophytes and arbuscular mycorrhizal fungi in subalpine grasslands
2013
International audience; In French subalpine grasslands, cessation of mowing promotes dominance of Festuca paniculata, which alters plant diversity and ecosystem functioning. One of the mechanisms underpinning such effects may be linked to simultaneous changes in the abundance of fungal symbionts such as endophytes and arbuscular mycorrhizal fungi. In field conditions, mowing reduced the abundance of the endophyte Neotyphodium sp. in leaves of F. paniculata by a factor of 6, and increased mycorrhizal densities by a factor of 15 in the soil. In greenhouse experiments, the mycorrhizal colonization of Trifolium pratense and Allium porrum increased 3- fold and 3.8- fold respectively in mown vs u…
Habitat modeling for cetacean management: Spatial distribution in the southern Pelagos Sanctuary (Mediterranean Sea)
2017
International audience; Effective management and conservation of wild populations requires knowledge of their habitats, especially by mean of quantitative analyses of their spatial distributions. The Pelagos Sanctuary is a dedicated marine protected area for Mediterranean marine mammals covering an area of 90,000km2 in the north-western Mediterranean Sea between Italy, France and the Principate of Monaco. In the south of the Sanctuary, i.e. along the Sardinian coast, a range of diverse human activities (cities, industry, fishery, tourism) exerts several current ad potential threats to cetacean populations. In addition, marine mammals are recognized by the EU Marine Strategy Framework Direct…
Ecological mechanisms can modify radiation effects in a key forest mammal of Chernobyl
2019
International audience; Nuclear accidents underpin the need to quantify the ecological mechanisms which determine injury to ecosystems from chronic low-dose radiation. Here, we tested the hypothesis that ecological mechanisms interact with ionizing radiation to affect natural populations in unexpected ways. We used large-scale replicated experiments and food manipulations in wild populations of the rodent, Myodes glareolus, inhabiting the region near the site of the Chernobyl disaster of 1986. We show linear decreases in breeding success with increasing ambient radiation levels with no evidence of any threshold below which effects are not seen. Food supplementation of experimental populatio…
Variations spatiales et temporelles des communautés adventices des cultures annuelles en France
2007
Although arable weed species are particularly well adapted to habitats characterised by high levels of disturbance(ploughing, harvest), the degree and rate at which agro-ecosytems have been transformed in the last 50 years in Europe(use of chemicals, changes in crop rotations) has led to profound changes in the composition and diversity of arable weedcommunities. This thesis provides an update on the composition and diversity of weed communities that can be foundacross the main crop types and regions of France. It also addresses two objectives i) applying (community) ecologytheories for the analysis and interpretation of spatial and temporal variations in weed communities and ii) using the …
Male bill colour and age are associated with parental abilities and breeding performance in blackbirds
2005
9 pages; International audience; In monogamous bird species, male parental investment may influence offspring fitness and females may gain advantages through mating with males providing extensive paternal care. However, paternal care is a benefit that can only be assessed indirectly because mate choice precedes paternal activities. Individual quality and age, both signalled by morphological characteristics, may reflect parental abilities. Because they may reflect individual foraging abilities, carotenoid-based colorations have been proposed to honestly signal parental quality. The blackbird (Turdus merula), a socially monogamous species, exhibits biparental care and males show bills that va…