background: coccidian infection in poultry is the most common infection in the world and is the cause of mortality and great economic losses in poultry production. objectives: this study was aimed to determine the frequency and eimeria species diversity in broiler farms of hamadan suburb, iran. methods: a total of 16 broiler farms were randomly selected with different production age in 2012. th...

in arid and semi-arid rangelands, grazing as one of the natural or human induced processes has direct and indirect effects on structure and dynamics of plant community and ecosystems. a study was done to analyze the effects of grazing on plant species diversity and plant functional types‘ (pfts) diversity of arid and semi-arid rangelands. we analyzed plant richness and diversity data from 75 sa...

the study was performed for assess the environmental factors affecting weed species diversity and composition of wheat (triticum aestivum l.) fields in jajarm, north-khorasan of iran, in 2009. the crop management (herbicide, amount of nitrogen applied and preceding crop type) and edaphic factors (ph, texture and content of phosphorus) of 16 fields were collected. shannon’s diversity index, spec...

Snow-fed river Pinder -a tributary of river Alaknanda in central Himalaya was explored for fish assemblages and habitat specificity. Altogether 27 fish species were reported from three orders, four families and nine genera. Cypriniformes order was dominating followed by Siluriformes and Salmoniformes. Shannon-Weiner diversity index (3.09 to 4.10) and Simpson index of diversity (0.81 to 0.92) of...

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 ...

forest reserves are one of the most important approaches in ecosystem management in iran. in order to determine the effects of reserve management on plants diversity (woody plants and ground flora) in three zones (core zone, buffer zone, and transmission zone of chamhesar pear forest reserve), we mapped land form units. then 18 main sampling units (20×50=1000 m2) distributed randomly were chose...

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...