Search results for "Species richnes"
showing 10 items of 427 documents
Ecomorphological predictors of natal dispersal distances in birds.
2008
1. Dispersal is one of the key ecological parameters but it is very difficult to quantify directly. As a consequence, empirical studies often ignore dispersal or use indirect measures. 2. Ringing data have previously been used to estimate the natal dispersal distances of 47 British passerine bird species. This provides an excellent opportunity to examine the potential of various indirect measures to predict natal dispersal distances in British birds. 3. We use a phylogenetic comparative framework and single- and multipredictor models including ecomorphological, behavioural or ecological traits to predict natal dispersal distance. 4. A multipredictor model that includes Kipp's distance (a me…
No uniform associations between parasite prevalence and environmental nutrients
2014
The resource quality of the host has been shown to affect parasite transmission success, prevalence, and virulence. Seasonal availability of environmental nutrients alters density and stoichiometric quality (carbon–nutrient ratios) of both producers and consumers, suggesting that nutrient availability may drive fluctuations in parasite prevalence patterns observed in nature. We examined the interactions between the population dynamics of a keystone herbivore, Daphnia, and its parasites, and their associations with water nutrient concentrations, resource quantity and quality, and other environmental variables (temperature, pH, oxygen concentration) in a small lake, using general linear model…
Effect of 30 years of road traffic abandonment on epiphytic moss diversity
2014
Road traffic emits a cocktail of pollutants that can influence the vegetation and plant diversity in neighboring areas. However, the recovery potential of bryophytes after traffic abandonment is still little explored. In addition, the effects of the main pollutants of road verges, such as metals and salinity, on moss flora need to be investigated. In our study, we compared the moss richness and diversity in two closely related veteran tree allees of high conservation importance. The allees in Gryżów and Lubrza, Poland, were chosen because of their similarity in age, geographical location, type of surrounding areas, and tree species. The only difference was that the trees in Gryżów had not b…
Soil and Plant Nitrogen Pools as Related to Plant Diversity in an Experimental Grassland
2007
Increasing plant species richness decreases soil NO 3 - concentrations in experimental plant mixtures, but the role of particular plant functional groups has remained unclear. Most analyses have focused on particular times of the year or were restricted to NO 3 - . We tested whether plant species richness or particular plant functional groups affect the size of plant-available N pools in soil (KCl-extractable NO 3 - , dissolved inorganic N and organic N [DON] and total dissolved N [TDN] in soil solution) and N concentrations and pools in aboveground biomass. Furthermore, we assessed seasonal variations in the effects of plant species richness and plant functional groups. The experimental gr…
The Coastal Levantine Area
2017
The Coastal Levantine area is a very diverse territory situated between the Cap de Creus and the Cap de la Nau. The wide variety of environments and ecological conditions that occur in this area determine its great diversity and richness from the vegetation point of view. Forest composition depends mainly on climatic factors, geomorphology and soil features, and are currently dominated by evergreen sclerophyllous (Quercus ilex, Q. rotundifolia, Q. suber), conifer (Pinus halepensis, P. pinaster, P. pinea, P. salzmannii, P. sylvestris), and deciduous (Fagus sylvatica, Quercus petraea) and semi-deciduous (Quercus faginea, Q. canariensis, Q. pubescens, Q. pyrenaica) species in inland areas with…
Exploring land snails’ response to habitat characteristics and their potential as bioindicators of riparian forest quality
2021
Abstract Riparian ecosystems are crucial for landscape-level biodiversity, especially in highly anthropic and agricultural areas. Although the low mobility of snails reduces their dispersal capacity and makes them vulnerable to habitat degradation, they are less commonly used as indicators. We evaluated the potential of land snails as bioindicators of riparian forest quality in central European riparian forests by surveying snail communities in relation to habitat characteristics that characterize its quality. Habitat characteristics were found to affect both snail abundance and species richness. The abundance of snail species increased with the forest continuity, forest width and abundance…
Responses of taxonomic distinctness and species diversity indices to anthropogenic impacts and natural environmental gradients in stream macroinverte…
2007
SUMMARY 1. Many studies have shown traditional species diversity indices to perform poorly in discriminating anthropogenic influences on biodiversity. By contrast, in marine systems, taxonomic distinctness indices that take into account the taxonomic relatedness of species have been shown to discriminate anthropogenic effects. However, few studies have examined the performance of taxonomic distinctness indices in freshwater systems. 2. We studied the performance of four species diversity indices and four taxonomic distinctness indices for detecting anthropogenic effects on stream macroinvertebrate assemblages. Further, we examined the effects of catchment type and area, as well as two varia…
Nunatak survival vs. tabula rasa in the Central Pyrenees: a study on the endemic plant species Borderea pyrenaica (Dioscoreaceae)
2007
14 páginas, 4 figuras, 2 tablas.
Conservation value of forest plantations for bird communities in western Kenya
2008
Tree plantations of native and exotic species are frequently used to compensate for forest loss in the tropics. However, these plantations may support lower species diversity and different communities than natural forest. We therefore investigated bird communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. We compared birds differing in habitat specialisation, i.e. forest specialists, generalists, and visitors. We recorded significant differences in mean species richness and number of individuals among the different forest types. Stands of natural forest and plantations of indigenous tree species comprised more sp…
High seedling recruitment of indigenous tree species in forest plantations in Kakamega Forest, western Kenya
2009
Tree plantations are often used to compensate for the destruction and conversion of natural forests in the tropics. An important question is whether these plantations allow for the regeneration of indigenous tree species and are expected to transform into more natural forests in the future. To evaluate the potential of differently managed forest types for seedling recruitment of indigenous tree species we studied structural characteristics as well as tree and seedling communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. Forest types differed considerably in structural characteristics and tree composition with st…