Search results for "diversity"
showing 10 items of 3950 documents
Human Impact Effects on Târnava River Basin Aquatic Biodiversity (Transylvania, Romania)
2020
Today the following categories of human impact are present in the Tarnava Watershed: hydrotechnical works, insufficiently treated/cleaned sewage, river substratum mineral exploitation/over-exploitation, manure leakage, artificial standing water, industry, river embankment, deforestation, pouching, etc., the first three of these inducing the highest impact on the lotic systems habitats and biodiversity.
First breeding evidence of marbled duck (Marmaronetta angustirostris) in Libya.
2014
4 pages; International audience; The first evidence of breeding of Marbled Duck (Marmaronetta angustirostris) in Libya, North Africa, is reported. In June 2012, at Mallaha wetland, in Tripoli, Libya, two dead ducklings were found that were later genetically identified as Marbled Duck. This breeding evidence suggests that this and other duck species may breed elsewhere in Libya. Better knowledge on Libyan, and more generally on north African, waterbirds is needed to document the population size and the status of these species. Such information will be important to secure the future of threatened species, such as the Marbled Duck.
Unravelling the bacterial diversity found in the semi-arid Tablas de Daimiel National Park wetland (central Spain)
2010
Our knowledge of microbial diversity in the environment is still limited, and there are many species as yet unidentified in both soil and water. Studies of the microbial diversity of wetland ecosystems have been neglected for years, as is the case of Tablas de Daimiel National Park (TDNP), a Spanish semi-arid wetland system of international importance in terms of waterfowl. We report the bacterial diversity of water column, sediment (upper and lower layers) and biofilm samples from the TDNP system using a 16S rRNA gene library approach. A sequence comparison of the 703 clones obtained revealed a number of bacterial phylogroups unreported to date. Bacterial diversity was high (Shannon values…
Byers Peninsula: A reference site for coastal, terrestrial and limnetic ecosystem studies in maritime Antarctica
2009
Abstract This article describes the development of an international and multidisciplinary project funded by the Spanish Polar Programme on Byers Peninsula (Livingston Island, South Shetlands). The project adopted Byers Peninsula as an international reference site for coastal and terrestrial (including inland waters) research within the framework of the International Polar Year initiative. Over 30 scientists from 12 countries and 26 institutions participated in the field work, and many others participated in the processing of the samples. The main themes investigated were: Holocene changes in climate, using both lacustrine sediment cores and palaeo-nests of penguins; limnology of the lakes, …
Changes to processes in estuaries and coastal waters due to intense multiple pressures:an introduction and synthesis
2015
From the 2013 ECSA conference ‘Estuaries and Coastal Areas in Times of Intense Change’ a theme emerged that has ended up being the focus of this Special Issue of Estuarine Coastal and Shelf Science, namely ‘Changes to processes in estuaries and coastal waters due to intense multiple pressures’. Manyparts of the world are continuing to experience unprecedented rates of economic growth, and those responsible for managing coastal and estuarine areas must respond accordingly. At the same time, global climate change and sea level rise are also continuing, placing new or more intense pressures on coastal areas that must be dealt with in ways that are as far as possible managed as a result of good…
Invasion ecology of the alien tussock grassNardus stricta(Poaceae) at Lake Pukaki, Canterbury, New Zealand
2005
Abstract The European matgrass Nardus stricta has naturalised in New Zealand, often on damp soils within wetlands and grasslands. In this paper, we present for the first time field data on the ecology of this alien invader in New Zealand, from eight kettle‐hole wetlands on lateral moraine along the western side of Lake Pukaki, South Canterbury. The invaded wetland sites were all acidic but varied in other soil characteristics. Nardus stricta was the most dominant species within these wetland communities with 40% of all plots showing more than 50% coverage, and 21% having more than 90% cover. Species richness (including vascular plants and mosses) at some sites was relatively high (c. 40 spe…
Response of wood-inhabiting fungal community to fragmentation in a beech forest landscape
2014
Fragmentation of natural habitats has become one of the main causes of the loss of biodiversity. To assess the effects of forest fragmentation on wood-inhabiting fungal community in a beech-dominated landscape, 15 differently shaped beech forest fragments were examined in northern Spain. This work covers all the wood-inhabiting macromycetes, including Basidiomycota and Ascomycota. A modelling approach was used to examine the predictability of the fungal community in a fragmented beech forest landscape. In the beech forest patches, a large proportion of edge, low tree densities and low levels of variety of woody debris caused a decrease of wood-inhabiting fungal richness. The fungal communit…
Zooplankton communities in doline lakes and pools, in relation to some bathymetric parameters and physical and chemical variables
1999
The zooplankton communities from several lakes and pools in three zones of a karstic area in central Spain were studied in spring and early autumn, in relation to morphometric, physical and chemical characteristics of the lakes. Zooplankton diversity was higher in autumn than in spring and it was positively correlated with lake size (area and depth) in spring, but not in early autumn. This effect is partially explained by the sharp zooplankton stratification in deep lakes, in early autumn. Some morphometric characteristics of lake basins were also correlated with the structure of zooplank- ton communities. Principal component analyses (PCA) and Two-Way Indicator Species Analysis (TWINSPAN) …
Yet another alien: a second species of Lepisiota spreading across the Canary Islands, Spain (Hymenoptera: Formicidae)
2018
The Canary Islands are a biologically important archipelago hosting many unique species, whose myrmecofauna is peculiarly rich in both endemic and introduced species. Lepisiota frauenfeldi cfr. kantarensis Forel, 1911 is reported for the first time from Fuerteventura and Tenerife. It is the second species of Lepisiota introduced in the archipelago in the last few years, and one of the few documented cases in which Lepisiota frauenfeldi (Mayr, 1855) s.l. acts as a successful tramp species. Comments are also given on taxonomic problems involving the L. frauenfeldi-group and related taxa. Finally, new additional information and comments are presented on the distribution of other alien ants spe…
Inferring True Species Richness and Complete Abundance Distribution in Six Reef-fish Communities from Red-sea, Using the Numerical Extrapolation of I…
2019
Even when ecological communities are incompletely sampled (which is most frequent in practice, at least for species-rich assemblages including many rare species), it remains possible to retrieve much more information than could be expected first, by applying numerical extrapolation to incomplete field data. Indeed, recently developed procedures of numerical extrapolation of partial samplings now allow to estimate, with fair accuracy, not only the number of the still unrecorded species but, moreover, the distribution of abundances of each of these unrecorded species, thereby making available the full range of the Species Abundance Distribution, despite dealing with incomplete data only. In t…