نتایج جستجو برای: diversity index

تعداد نتایج: 577656  

Journal: :پژوهش های زراعی ایران 0
مریم جهانی کندری علیرضا کوچکی مهدی نصیری محلاتی پرویز رضوانی مقدم

in order to investigate diversity of weed species in wheat fields in eastern parts of mashhad, an investigation was made in the year 2009. wheat fields was classified based on the acreage from 3-5 ha, 5-10 ha and higher than 10 ha. sampling was made randomly by a quadrate 0.5×0.5 in 9 fields of each group from jointing to heading of wheat in tow separate stages. type and total number of weeds w...

ژورنال: علوم آب و خاک 2008
اصغرزاده, احمد , حق نیا, غلامحسین , خاوازی, کاظم , کریمی, اسماعیل , لکزیان, امیر ,

  It is important to investigate the genetic diversity and evaluate symbiotic effectiveness of the indigenous rhizobial population. It helps understand the responses of indigenous isolates to different rhizobial inoculants. In spite of the importance of bacterial diversity, there are a few scientific reports about it in Iranian soils. Genetic diversity of 150 isolates of Sinorhizobium isolated ...

Journal: :Journal of environmental biology 2008
B Padmanabha S L Belagali

Ostracods are small crustaceans found in aquatic habitats and the present paper deals with the role of water quality index on their population diversity and seasonal fluctuations in the four lakes of Mysore city The present investigation was carried out from July 2004 to June 2005. The study revealed highest water quality index and population density of ostracods during summer and least during ...

Journal: :international journal of advanced biological and biomedical research 2013
hamid ahani hamid jalilvand

forests are biologically diverse systems, representing some of the richest biological areas on earth. they offer a variety of habitats for plants, animals and micro-organisms. however, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. biodiversity is the variation of life forms within a given ecosystem, biome, or on t...

2010
Iván Alfaro

Data from 247 global software development teams were used to examine the impact of temporal dispersion and leadership roles on the relationship between nationality diversity and team performance. Nationality diversity was positively related to team performance when project leaders regularly coordinate and monitor team members’ activities, and acted as mentors and facilitator. However, when nati...

Journal: :بوم شناسی کشاورزی 0
علی قنبری زهره قویدل رضا قربانی قدریه محمودی

in order to study the different levels of irrigation on diversity, density and compound of weed species in corn field, experiment was conducted at agricultural research station, ferdowsi university of mashhad during growing season of 2008-2009. the experiment was with four levels of irrigation (6130, 7290, 8800 and 12330 m3) and four levels of weed control (complete control, broad-leaves contro...

ژورنال: مرتع 2022
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Background and objectives: In order to properly manage rangeland ecosystems, it is necessary to study the relationship between ecological factors in nature such as elevation, climate and soil factors with vegetation and living organisms. In this regard, the present study was conducted to investigate the relationship between species diversity and environmental factors (Physical and chemical char...

Journal: :J. Applied Mathematics 2013
Naiqi Song Jin-Tun Zhang

Functional diversity in plant communities is a key driver of ecosystem processes. The effective methods for measuring functional diversity are important in ecological studies. A new method based on neural network, self-organizing feature map (SOFM index), was put forward and described. A case application to the study of functional diversity of Phellodendron amurense communities in Xiaolongmen F...

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