Search results for "Ecosystem diversity"
showing 8 items of 18 documents
Identification problems of arid environments in the Neogene–Quaternary mammal record of Spain
2006
Abstract In this work, we investigate if broadly used methodologies are adequate to detect periods of aridity based on the Spanish fossil record and try to infer which of them were more or less severe. Thus, we present a qualitative statistical approach to two popular palaeoecological methodologies: ecological diversity and cenograms. Discriminant models, derived from modern localities of known biome, determined the probable biomes of Neogene–Quaternary fossil assemblages. Principal component analyses (PCA) provided additional inference on their ordination within an aridity gradient. While models work adequately with modern faunas, the analyses of the palaeocommunities showed that their eco…
Agricultural landscapes and biodiversity conservation: a case study in Sicily (Italy)
2015
The diversity of life is made up not only of the diversity of plants and animal species, habitats and ecosystems, but also of the diversity of human cultures. These diversities interact with one another in complex ways and express the mutual adaptation between humans and the environment at local level. Sicilian traditional agro-ecosystems, due to the history of the territory and the resulting social and economic context, are configured in a heterogeneous mosaic rich in residual features of environmental value, which enhance the connectivity of the ecological network and support a high proportion of species that are rare or of conservation concern. As a case study we analyzed the characteris…
The relevance of ecological status to ecosystem functions and services in a large boreal lake
2014
Summary Environmental conventions aim to protect ecosystem structures and functions to provide goods and services for mankind. The degree of aquatic ecosystem naturalness, or ecological status as it is defined in the Water Framework Directive (WFD) of the European Union, is notionally linked to supplies of ecosystem services. In practice, these links have rarely been documented or even investigated, and to justify conservation and management objectives based on the status indicators, it is essential to demonstrate their relationships to ecosystem functions and services. The WFD requires member states to classify their surface waters aiming to achieve good ecological status of water bodies. …
ECOLOGICAL ASSESSMENT AS A FIRST STEP IN THE EVALUATION OF ECOSYSTEM SERVICES PROVIDED BY LOTIC ECOSYSTEMS
2013
ABSTRACT The ecosystems offer to the socio-economic system a series of goods and services derived from their processes and biodiversity. Ecosystem services offered by a river are at their highest potential when the river status is close to the natural one. Once the river is affected by human impact due to resources exploitation, hydro technical works, water abstraction or improper land use, the ecological status declines and the ecosystem services become scarce. This is why an ecological assessment is necessary in order to establish the connection between the ecosystem services and the human impact. In this paper, the ecological assessment of Timiș River was done, allowing the classificatio…
Diversité microbienne des sols : stratégie méthodologique, distribution spatiale et traduction en fonctionnement biologique
2011
International audience; Since the development of industrialization, urbanization and agriculture, soils have been subjected to numerous variations in environmental conditions, which have resulted in modifications of the taxonomic diversity and functioning of the indigenous microbial communities. As a consequence, the functional significance of these losses/modifications of biodiversity, in terms of the capacity of ecosystems to maintain the functions and services on which humanity depends, is now of pivotal importance. In this context, one of the main challenges in soil microbial ecology is to better understand and predict the processes that drive soil microbial diversity and the link betwe…
Pre-Messinian ecological diversity of Mediterranean sharks revealed by the study of their dermal denticles
2020
The Messinian salinity crisis (~5.59 Ma) is regarded as one of the most determining events for the recent evolutionary and palaeobiogeographic history of the Mediterranean biota. The impact of such episode has usually been assessed by evaluating the associated taxonomic turnover, however its consequences have rarely been interpreted from an ecological perspective. Here we assess the functional diversity of shark dermal denticles in a Serravallian locality from southeast Spain, providing a primary view into the pre-Messinian ecological diversity of shark communities from the Western Mediterranean. Our results reveal a high diversity of functional types of dermal denticles including dermal de…
Salicornia L. (Amaranthaceae) in South Africa and Namibia: rapid spread and ecological diversification of cryptic species
2013
In Salicornia, morphology does not provide reliable diagnostic characters supporting the true extent of evolutionary divergence in the genus, and species concepts have been challenged by molecular analyses. Here, we report the results of an analysis of 91 accessions of the S. meyeriana complex from South Africa and Namibia using the measurements of 38 morphological traits and external transcribed spacer (ETS) sequence data. Morphological data were analysed using discriminant analysis, principal coordinate analysis and nonmetric multidimensional scaling. Phylogenetic divergence was compared with the geographical and ecological diversity of the sampled populations. Tree topology corresponds t…
Soil as a Support of Biodiversity and Functions
2014
The soil is a major reservoir of biological diversity on our planet. It also shelters numerous biological and ecological processes and therefore contributes to the production of a considerable number of ecosystem services. Among the ecological, social and economic services identified, the role of soil as a reservoir of diversity has now been well established, along with its role in nutrient cycling, supporting primary productivity, pollution removal and storing carbon. Since the development of industrialization, urbanization and agriculture, soils have been subjected to numerous variations in environmental conditions, which have resulted in modifications of the diversity of the indigenous m…