نتایج جستجو برای: the species diversity

تعداد نتایج: 16168662  

Journal: :یافته های تحقیقاتی در گیاهان زراعی و باغی 0
سمانه راهب موسسه تحقیقات مرکبات ایران، رامسر مرتضی مبلغی بهروز گلعین

in order to investigate the effect of different cover crops on density and diversity of weeds, the researcher carried out an experiment in randomized complete block design with seven treatments and three replications for two years (2009-2010) in iran citrus research institute. treatments included planting four cover crops of legumes such as clover (trifolium alexandrinum l.), green bean (phaseo...

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 ...

Zagros forests are one of the important natural ecosystems in Iran with high plant diversity and variety of plant communities. In recent decades, fire events have frequently occurred in some of these ecosystems. The purpose of this research is to investigate the composition and diversity of herbaceous species after nine years of fire occurrence in the forests of Zagros in western Iran. For this...

Journal: :caspian journal of environmental sciences 2014
s. bagheri m. fallahi

phytoplankton taxa composition of the caspian sea were evaluated by using samples collected at 12 stations along the iranian coast of the caspian sea between 1996 and 2010. this study identified 158 phytoplankton species consisted of diatoms (70 species), dinoflagellates (23 species), chlorophytes (29 species), cyanophytes (31 species), and euglenoids (5 species). the dominant species were the ...

A.R. Mirzajani, B. Kiabi S.A. Nezami

In the present study, some ecological factors were studied for Amphipoda at different depths. The Shannon, Margalef, and Hill indices were used to determine the  species diversity, richness and evenness, respectively. In addition, the association and niche overlap values were estimated. Indices of species richness and diversity were highest at 50 and 100m depths, respectively.  The ordination o...

A.R. Mirzajani, B. Kiabi, S.A. Nezami,

In the present study, some ecological factors were studied for Amphipoda at different depths. The Shannon, Margalef, and Hill indices were used to determine the  species diversity, richness and evenness, respectively. In addition, the association and niche overlap values were estimated. Indices of species richness and diversity were highest at 50 and 100m depths, respectively.  The or...

Assessment of forest soil and vegetation characteristics provides basic and essential information for the protection and rehabilitation measures in forest ecosystems. Therefore, regard to the importance of this issue, the distribution of different soil properties and vegetation diversity in relation to conservation management and degradation investigated in the oak forests of Ilam province usin...

Journal: :جنگل و فرآورده های چوب 0
علی اشرف مهرابی عضو هیأت علمی دانشکده کشاورزی و منابع طبیعی دانشگاه ایلام پیمان غلامی دانشگاه آزاد اسلامی واحد کرمانشاه علیرضا اطمینان استادیار اصلاح نباتات، دانشگاه آزاد اسلامی واحد کرمانشاه، دانشکده دانشکده تحصیلات تکمیلی سمیرا محمدی دانشکده کشاورزی و منابع طبیعی دانشگاه ایلام

pistacia atlantica subsp. mutica is one of the most valuable forest tree species in iran that has been severely exploited for a long time. therefore, understanding the genetic diversity of different populations can be an important step towards the development and restoration of the habitat of this invaluable tree species. in this study, in order to study the genetic diversity, 10 populations in...

Journal: :crop breeding journal 0
a. aalami agricultural sciences, university of guilan, rasht, iran. b. abdollahi mandoulakani h. azizi f. masoumi s. safiyar n. karami

genetic drift of germplasm in cultivated wheat is good motivation for studying genetic diversity in its wild relatives. in this study, r-rap, a new retrotransposon-based marker, was applied to assess the structure and genetic diversity of 30 accessions of aegilops sp. originating from different geographical regions of iran. the 15 r-rap primer combinations revealed a total of 338 bands ranging ...

Knowledge of the relationships between biotic components of rangeland ecosystem i.e. herbivores and plants is important for range managers. In order to study herbivorse grazing intensity on plant species diversity, an experiment was conductef using fuor grazing treatments in darrehshar rangelands, Ilam province in 2015. Plant species data were taken based on a randomized-systematic sampling met...

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