in order to study the effect of canopy gap size on species diversity and composition in mixed stands, a reserved area which located in asalem forests was selected. all of gaps in this area identified and were divided into four categories: small gaps (1000 m2). in each category, 21 of gaps with a relatively homogeneous in terms of an aspect and slope were selected. the major and minor diameter o...

fish biodiversity investigation in urmia basin which is a part of irano-anatolian hot spot aimed to determine the state of fish in this endorheic basin. based on the obtained results, freshwater fish species of the urmia basin comprise 29 species in 25 genera, 7 families, 5 orders and one class. the most diverse order is the cypriniformes with 23 species (79.31%) followed by salmoniformes and p...

Plant diversityis essential to maintain the health of planet's ecosystems. Conservation of biodiversity is necessary for the ecological stability and productivity in natural ecosystems. The aim of this research was to study the biodiversity and richness of plant species (including trees, shrubs and grasses) related to the environmental factors (soil and physiography) in the forests of Zagros, w...

the diversity and distribution of the rotifers family notommatidae was studied in the northwest, the south and the southwest of iran. in total, 29 species were identified, of which, 25 are new records for the country. new records include the following species: cephalodella forficata, c. cf. mus, c. vittata, c. ventripes, c. lepida, c. inquilina, c. gibboides, c. tincaformis , c. obvia, c. stere...

Fire, as a natural ecological disturbance factor in forest, this study located in the Marivan region, Northern Zagros forest, and western Iranian state of Kurdistan. In each burned and unburned area 30 circle sample plot (1000 m2) were collected by randomized–systematic method in the 100×200 m net (in total 60 plots). In every sample plot the kind of species, number of tree, the heig...

fifteen yarrow populations from different species achillea millefolium l., a. biebersteinii l. and a. nobilis, from different geographical areas of iran were studied using 24 morphological traits and peroxidase profiles. comparison of mean values of different phenotypic traits show a. millefolium and a. biebersteinii l. had higher plant height and crown diameter; however, a. nobilis had higher ...

introduction agricultural biodiversity has spatial, temporal and scale dimensions especially at agro-ecosystem levels. these agro-ecosystems that are used for agriculture are determined by three sets of factors: the genetic resources (biodiversity), the physical environment and the human management practices. most agricultural areas can be returned to their natural landscape after subsequent ge...