Search results for "Richness"
showing 10 items of 447 documents
Aquatic invertebrate assemblages in ponds from coastal Mediterranean wetlands
2014
Invertebrate aquatic assemblages in ponds from Mediterranean wetlands are composed of organisms belonging to different taxonomic groups, which present a wide range of sizes (from small rotifers to large crustaceans or insects). Although they are often sampled and analyzed separately, the ecological links among these organisms should be considered, especially in very shallow waters. In our study, invertebrate assemblages (including micro-, macrozooplankton and macroinvertebrates) were characterized in eight shal- low lakes from Mediterranean wetlands in Southeastern Spain. A great spatial and temporal variability in the assemblages and in some environmental features was observed. The communi…
Fungal Assemblages Associated with Roots of Halophytic and Non-halophytic Plant Species Vary Differentially Along a Salinity Gradient
2012
Structure of fungal communities is known to be influenced by host plants and environmental conditions. However, in most cases, the dynamics of these variation patterns are poorly understood. In this work, we compared richness, diversity, and composition between assemblages of endophytic and rhizospheric fungi associated to roots of two plants with different lifestyles: the halophyte Inula crithmoides and the non-halophyte I. viscosa (syn. Dittrichia viscosa L.), along a spatially short salinity gradient. Roots and rhizospheric soil from these plants were collected at three points between a salt marsh and a sand dune, and fungi were isolated and characterized by ITS rDNA sequencing. Isolates…
Plant species richness, biogeographic and conservation interest of the vascular flora of the satellite islands of Sicily: patterns, driving forces an…
2013
The vascular flora has been investigated on about 60 of the approximately 100 islands and islets of the Sicilian archipelago. This paper provides detailed information on the number of exclusive, rare, or threatened vascular plants living on these islands and islets. Focusing on the 18 most-investigated islets, we evaluate the extent to which species richness, rate of endemism, number of alien plants, and number of terrestrial habitats have been influenced by 1) geographical setting, 2) geological history, 3) geo-pedological variability, 4) bioclimate, 5) number and patchiness of local plant communities, and 6) natural and human disturbance history and regime. Special attention is directed t…
Ocean acidification can mediate biodiversity shifts by changing biogenic habitat
2016
The effects of ocean acidification (OA) on the structure and complexity of coastal marine biogenic habitat have been broadly overlooked. Here we explore how declining pH and carbonate saturation may affect the structural complexity of four major biogenic habitats. Our analyses predict that indirect effects driven by OA on habitat-forming organisms could lead to lower species diversity in coral reefs, mussel beds and some macroalgal habitats, but increases in seagrass and other macroalgal habitats. Available in situ data support the prediction of decreased biodiversity in coral reefs, but not the prediction of seagrass bed gains. Thus, OA-driven habitat loss may exacerbate the direct negativ…
Nematode community response to fish-farm impact in the western Mediterranean.
2002
A previous investigation on fish-farm biodeposition effects on benthos, carried out in the Gaeta Gulf (northwestern Mediterranean Sea), revealed a strong impact on meiofaunal assemblages. This study implements these findings by examining in detail the nematode assemblage and its response to organic enrichment from the start of a fish farm activity to the conclusion of the fish rearing cycle. Density, community structure and individual size were utilised for univariate (genus, trophic diversity and abundance patterns) and multivariate analyses (MDS) in order to identify the best descriptors of impact and the response of the nematode assemblages. Nematodes displayed significantly reduced dens…
Priority areas for the conservation of Atlantic forest large mammals
2009
Large mammal faunas in tropical forest landscapes are widely affected by habitat fragmentation and hunting, yet the environmental determinants of their patterns of abundance remain poorly understood at large spatial scales. We analysed population abundance and biomass of 31 species of medium to large-bodied mammal species at 38 Atlantic forest sites (including three islands, 26 forest fragments and six continuous forest sites) as related to forest type, level of hunting pressure and forest fragment size using ANCOVAs. We also derived a novel measure of mammal conservation importance for each site based on a "Mammalian Conservation Priority index" (MPi) which incorporates information on spec…
The effects of protection measures on fish assemblage in the Plemmirio marine reserve (Central Mediterranean Sea, Italy): A first assessment 5years a…
2013
This 2-year study was aimed to investigate the early effects of protection measures on fish assemblage in the Plemmirio marine reserve and to evaluate its level of enforcement. Sampling was carried out by means of underwater visual census techniques in four sampling sites within the reserve boundaries and eight outside the reserve. Results showed significant inside/outside differences in the multivariate abundance of fish assemblage. These results were confirmed and exemplified by significant univariate differences between locations for total abundance, Species Richness and diversity of the fish assemblage; values of these metrics were higher inside the reserve than outside. Small fish size…
Cladocera (Branchiopoda, Anomopoda, Ctenopoda, and Onychopoda) from Sicilian inland waters: an updated inventory
2005
An extensive survey aimed at updating and increasing the knowledge on species richness and distribution of Cladocera (Branchiopoda) in Sicily has been carried out in the period 2000-2004. More than 250 water bodies, mainly temporary, have been sampled on the whole Sicilian territory and the circum-Sicilian islands. This sampling effort led to the discovery of several species new to the fauna of the island and, coupled with a careful bibliographic review, allowed the realization of an updated checklist that includes 57 species definitely present on the island (only 33 were formerly known), and two more, whose actual presence in Sicily is dubious and needs confirmation. The chorological spect…
Hiding behaviour ofOxynoe olivacea(Mollusca: Opisthobranchia: Sacoglossa) in the invasive seaweedCaulerpa taxifolia
2013
The occurrence of the invasive seaweed Caulerpa taxifolia in the Straits of Messina (Italy) provides an excellent opportunity to examine the spatial and temporal patterns of abundance of the endemic Mediterranean sacoglossan Oxynoe olivacea. Densities of this species were recorded in March, June and October 2000 on three different habitats: the underside of boulders (UNB), the upper side of boulders (UPB), and the surface of concrete blocks (CB). Results showed that in March, O. olivacea was consistently more abundant on UNB whereas in June it was present exclusively on CB. The density of O. olivacea was similar in the three habitats in October. The hiding behaviour of O. olivacea and its s…
Sustainable Exploitation and Conservation of the Endemic Lake Baikal Sponge (Lubomirskia baicalensis) for Application in Nanobiotechnology
2009
The large sub-continent of Siberia is one of the richest mineral and oil resources on Earth. In its center, one region has gained prominence: Lake Baikal. It is one of the oldest, the deepest, and the lake with the greatest volume on Earth and is inhabited by more than 1,500 endemic species. It was Pallas (1771) who discovered in the lake a sponge species, Lubomirskia baicalensis (Porifera: Demospongiae), which dominates Lake Baikal's littoral-zone benthos. This sponge species has a distinguished, pronounced body plan which is composed of modules. The application of molecular biological and cell biological techniques has allowed an insight into the richness of the genomic regulatory systems…