نتایج جستجو برای: species diversity

تعداد نتایج: 692837  

G. Singh, N.K. Agarwal, U.S. Rawat,

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...

Journal: :جنگل و فرآورده های چوب 0
بیت الله امان زاده دانشجوی دکتری علوم جنگل، دانشکدﮤ منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران محمد رضا پورمجیدیان دانشیار، دانشکدﮤ منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران خسرو ثاقب طالبی دانشیار پژوهش، مؤسسة تحقیقات جنگل‏ها و مراتع کشور، تهران، ایران سید محمد حجتی دانشیار، دانشکدﮤ منابع طبیعی، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران

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...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علوم کشاورزی و منابع طبیعی گرگان - دانشکده مرتع و آبخیزداری و شیلات و محیط زیست 1391

مراتع حدود نیمی از خشکی های جهان را در بر دارند و پوشش گیاهی آن در نتیجه تأثیر متقابل محیط و موجودات زنده به وجود آمده است و به عنوان یک اکوسیستم طبیعی مدیریت می شوند. علاوه بر مراتع، راه ها در عصر حاضر نیز از اجزا مهم و زیرساخت های اصلی زندگی نوین و توسعه کشورها به شمار می روند. جاده ها ساخته دست بشر هستند و جوامع گیاهی کنار جاده تحت تأثیر ساخت و ساز قرار دارند. پوشش "رودرال" به مجموعه ای از پ...

Journal: :بوم شناسی کشاورزی 0
علیرضا باقری رضا قربانی محمد بنایان اول اورس شافنر

considering the importance of biodiversity conservation and protection assessment activities, the present filed study was conducted with aim to compare vegetation diversity of two areas with different levels of protection including ghorkhod protected area with seasonal grazing and golestan national park without grazing, during spring and summer of 2011. four replications were selected in each a...

Journal: :جنگل و فرآورده های چوب 0
سمیه کرمی راد دانشگاه تهران احسان عبدی دانشکده منابع طبیعی باریس مجنونیان دانشگاه تهران وحید اعتماد دانشگاه تهران هرمز سهرابی دانشگاه تربیت مدرس

road construction is one of the effective factors for ecological changes which affects diversity and species composition in forest roads edges. this research was performed in kheirud forest to evaluate herbaceous diversity and tree regeneration establishment in different distances from road edge. for this purpose, we sampled herbaceous and tree species regeneration in 0,5,10,25, 50 and 100 m di...

2003

Polyclad flatworms resemble a taxon with an incredible diversity in tropical waters (Newman & Cannon, 1994; see section: Taxonomy). For quite a long time, the colour pattern of the splendidly coloured worms alone has been considered sufficient for their classification (Hyman, 1954, 1959). However, it has been shown that for identification of many species this is not enough for a reliable identi...

Journal: :iranian journal of ichthyology 0
hamid ghasemi eastern azerbaijan agriculture and natural resources research center, p.o. box: 53555-141 tabriz, iran. arash jouladeh roudbar department of fisheries, faculty of natural resources, sari university of agricultural sciences and natural resources, sari, iran. soheil eagderi department of fisheries, faculty of natural resources, university of tehran, karaj, iran. keivan abbasi aquatic ecology department of the inland water aquaculture research center, p.o. box 66, bandar anzali, iran. saber vatandoust department of fisheries, babol branch of islamic azad university, mazandaran, iran. hamid reza esmaeili department of biology, college of sciences, shiraz university, shiraz, 71454–iran.

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...

Journal: :caspian journal of environmental sciences 2010
r. malekzadeh viayeh

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...

In order to investigate the diversity of plant species in forested areas, this study was carried out in forestry near the Khuzestan Steel Industries Company with a total area of 60 hectares in the southeast of Ahwaz, Khuzestan province. For this purpose, 30 plot of 20 × 20 meters in size were systematically randomized in the forested area and 30 samples were taken in the control area. Within ea...

     Maintaining genomic diversity in goat populations in different parts of Iran is essential for breeding programs, increasing production, survival, resistance to diseases, and various environmental changing conditions. The aim of the present study was to determine the sequence of HVR1 from the mitochondrial genome of Iranian native goats including Sistani, Pakistani, Black and Lorry ecotypes...

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