The analysis of ecological diversity on a given study region constitutes a key topic in environmental studies. The quantitative aspects of ecological diversity are usually detected by means of the diversity indexes, which are ad hoc functions of the species abundance. Obviously, species abundance is unknown in practice. Hence, in order to obtain inference on diversity indexes, species abundance...

In this paper, we introduce a patch connectivity index and analyse its changes in relation to ecotope diversity and human impact intensity. Land-use maps of the newly born wetland at the Yellow River Delta of 1984, 1991 and 1996 were produced by applying an unsupervised and a supervised classification algorithm to the corresponding three scenes of Landsat Thematic Mapper (TM) images. A model fo...

The landscape pattern of Daqing city, China has undergone a significant change in 1990–2000 as a result of the rapid urbanization process. The focus of this paper is to quantitatively capture landscape pattern and its spatial dynamics of Daqing city at the landscape level over the 10 years span. A traditional supervised classification (maximum likelihood classification) was carried out on Daqin...

in order to investigate diversity of weed species in wheat fields in eastern parts of mashhad, an investigation was made in the year 2009. wheat fields was classified based on the acreage from 3-5 ha, 5-10 ha and higher than 10 ha. sampling was made randomly by a quadrate 0.5×0.5 in 9 fields of each group from jointing to heading of wheat in tow separate stages. type and total number of weeds w...

Overgrazing and mining affect vegetation, particularly in mountains. At times, it goes to such an extent that the plant species become vulnerable and slowly extinct from its habitat. Such endemic species need to be protected. One such endemic species Hedysarum chaiyrakanicum Kurbatsky, a vulnerable steppe vegetation of Tuva Republic, Russia was evaluated for its genetic diversity and taxonomic ...

Amorphophallus konjac is an economically important crop. In order to provide baseline information for sustainable development and conservation of the wild plant resources of A. konjac, we studied the genetic diversity and population structure of this species using amplified fragment length polymorphism (AFLP) molecular markers. We sampled 139 individuals from 10 wild populations of A. konjac in...

The Ibirité reservoir is an urban and eutrophic environment, with regular occurrences of cyanobacteria blooms. The reservoir is warm monomict and remains stratified most of the year, circulating in the dry season (winter). During the hydrological cycle of October/07 to October/08 there were four scenarios with different environmental conditions, which influenced the structure of the zooplankton...