نتایج جستجو برای: diversity index

تعداد نتایج: 577656  

Journal: :دانش گیاه پزشکی ایران 0
الهام اکبریان فیروزآبادی دانشجوی سابق کارشناسی ارشد، دانشکده کشاورزی، دانشگاه شهید چمران اهواز بهزاد حبیب پور استادیار، دانشکده کشاورزی، دانشگاه شهید چمران اهواز حمید گله داری دانشیار، دانشکده کشاورزی، دانشگاه شهید چمران اهواز پرویز شیشه بر استاد، دانشکده کشاورزی، دانشگاه شهید چمران اهواز

microcerotermes diversus (silvestri) (isoptera: termitidae), an important wood pest in ahwaz (khuzestan, iran), causes serious economic damage to cellulosic products in buildings. to investigate the genetic diversity of this pest, 13 populations from different areas of khuzestan province as well as two samples from khark island and bandar abbas were collected. following dna extraction a fragmen...

Journal: :international journal of advanced biological and biomedical research 0
maziar haidari young researchers club, sanandaj branch, islamic azad university, sanandaj, iran

silvicultural operation need to notice the plant species diversity in forest. to this study gomarlang district in marivan region, northern zagros forest was selected. selected 100 ha area because have similar physiography condition (north aspect and 1650 to 1800 m s.a.l. in study area 100 micro plots of 5m by 5 m (25 m2) including the species and the numbers of this species randomized-systemati...

Journal: :جنگل و فرآورده های چوب 0
آزاده دلجویی کارشناس ارشد مهندسی جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران احسان عبدی دانشیار گروه جنگلداری و اقتصاد جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران باریس مجنونیان استاد گروه جنگلداری و اقتصاد جنگل دانشکدة منابع طبیعی دانشگاه تهران، کرج، ایران

forest roads are directions in natural habitats that used to transport wood products, secondary forest products and recreation. constructing forest roads causes trees clearing with specified width thus lead to direct or indirect changes in forest ecosystems and forest environment. this study aims to assess the changes of diversity and richness indices in main and secondary forest roads in a par...

Journal: :Mathematical biosciences 2008
Dimitri Vanpeteghem Olivier Zemb Bart Haegeman

Hubbell's neutral model has become a major paradigm in ecology. Whereas the steady-state structure is well understood, results about the dynamical aspects of the model are scarce. Here we derive dynamical equations for the Simpson diversity index. Both mean and variance of the diversity are proven to satisfy stable linear system dynamics. We show that in the stationary limit we indeed recover p...

Habib Yazdanshenas Hossein Arzani Hossein Azarnivand Malihe Nasiri Mohammad jafari

Understanding the plant species diversity could be used as an importantindicator applied for the natural areas management. The aim of this study was toinvestigate the relationships between soil characterizes with distribution and diversity ofplant in vegetation types in Karvan district (located in west of Isfahan province). For thispurpose, three vegetation types were selected as follows: Scari...

Journal: :iranian journal of ichthyology 0
asghar abdoli department of biodiversity and ecosystem management, sciences research institute, shahid beheshti university. tehran, iran. mehdi naderi department of ecology, caspian ecology academe, iranian fisheries research organization, sari, iran. hojatolah foroughifard persian gulf and oman sea ecological research institute, bandar abbas, iran. bahram h kiabi department of biology, shahid beheshti university, evin, tehran, iran.

fish species diversity, distribution and abundance were studied in the sardabrud and chalus rivers, in the southern caspian sea basin, during 1992 and 1993 in five and four stations respectively, by monthly collections using electrofishing device. in total, 3200 fish specimens, including 15 species in sardabrud river and 12 species in chalus river, were investigated. the fish comprised of 13 ge...

Journal: :محیط شناسی 0
منصور زیبایی آذر شیخ زین الدین

in this study an attempt has been made to empirically examine the relationship between biodiversity and economic growth using indicators of species diversity and income per capita as proxies for biodiversity and economic growth, respectively.also the effects of agricultural value added as a percentage of gdp, trade freedom index, exchange rate, population, percantage of land developed for agric...

Ahmad Bahrebar, Ayat Rohina, Behroz Behrouzirad Mostafa Bahrebar Seied Mehdi Amininasab Seied Saeed Mohaghegh

This study was performed  in second half of year 2009.For bird counting , monthly from Septamber until March 2009. Total counted birds in Maroon lake were (971). Maximum number of counted birds was in February  (191) and minimum of counted was in Septamber (95). Total counted birds in Jaizan were (385. Maximum number of the counted bird was in February (84) and minimum of counted (52) was in Ja...

A. Abdoli B.H. Kiabi S.M. Kalantarian,

The gobies are non-commercial fishes in the Iranian waters of the Caspian Sea for which population dynamics and stock status are poorly known. In this survey, we tried to define species diversity and catch per unit effort (CPUE) of Gobiidae by using beach seine nets in Salmanshahr, the southern Caspian Sea. From March 2011 to April 2012, 224 specimens representing 4 gobiid species, belonging to...

Abdoli, A., Kalantarian, S.M., Kiabi, B.H.,

The gobies are non-commercial fishes in the Iranian waters of the Caspian Sea for which population dynamics and stock status are poorly known. In this survey, we tried to define species diversity and catch per unit effort (CPUE) of Gobiidae by using beach seine nets in Salmanshahr, the southern Caspian Sea. From March 2011 to April 2012, 224 specimens representing 4 gobiid species, belonging to...

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