Numerical and parametrical indices are two of the most important and most widely used indices for assessing biodiversity in different societies. Nevertheless, their efficiency and selection in various ecosystems has always been one of the challenging issues of ecology. In this study, the numerical indices of diversity, richness and eveness, as well as abundance–ranking distribution models inclu...

Physiographic factors, due to their special role in determining some climatic and edaphic parameters, always influence the diversity and richness of plant species. Due to the importance of Arasbaran vegetation area, the present study was conducted to investigate the biodiversity of woody species of Kalaleh yew habitat in relation to physiographic factors. For this purpose, 62 plots of 4 square ...

Determination of factors affecting on species distribution and diversity, especially in desert areas is the most important factor in rangeland ecosystems management for encountering biological stress. In order to evaluate the effect of physiographic factors on plant biodiversity in natural ecosystems of Kakhk Gonabad, this research was conducted in spring 2014. First, by overlaying four maps of...

Zooplanktons have an important role in food chain of the aquatic ecosystems, which acts as a food chain link between producers (phytoplankton) and higher nutritional levels. The purpose of this research was to identify and study the zooplankton density in the southeastern basin of the Caspian Sea (Gorgan Bay). Sampling was performed seasonally and samples were collected by zooplankton net (36 c...

In this study, different indices of vegetation cover variations and different physicochemical properties of soil in three treatments of flood spreading, enclosure and grazing (control) were investigated and compared in in the region of Peshert in Mazandaran province. In order to measure different soil characteristics, 18 soil samples (six withdrawals at any treatment) from a depth of zero to 30...

Background and Aims: Ticks are external parasites that can be vectors of several diseases agents. A survey was carried out to determine distribution and biological diversity of hard tick species in Maraveh Tapeh County, Golestan Province in spring 2016. Materials and methods: In 10 selected villages in study area, About 29 cattle, 99 sheep, 62 goats and 11 camels were inspected for tick infest...