نتایج جستجو برای: richness

تعداد نتایج: 20745  

1998
Ronald G. Addie Moshe Zukerman Timothy D. Neame R. G. Addie

A much clearer picture of the progress towards an integrated high speed multi-service network is now emerging. Such networks were anticipated over twenty years ago, at a time when packet switching was just another way to transmit data. Now the technology is so mature that media barons are organising their investments in order to take advantage of the proot. Many of the technical problems are no...

2008
T. Bolger Karen H. Beard Andrew V. Suarez Ted J. Case

Habitat fragmentation and invasive species often contribute to the decline of native taxa. Since the penetration of non-native species into natural habitat may be facilitated by habitat fragmentation, it is important to examine how these two factors interact. Previous research documented that, in contrast to most other arthropod taxa, spiders increased in density and morphospecies richness with...

2017
Carolyn Polson

Many regulatory authorities set water quality objectives or thresholds based on nutrient concentrations to safeguard aquatic ecosystem health. But do these criteria adequately assess the biological and ecological status? Our research has been focussing on the performance of constructed wetlands for water quality improvement and ecosystem health. In this paper we present data on macroinvertebrat...

2018
Masanori Takano Genki Ichinose

Human social strategies have evolved as an adaption to behave in complex societies. In such societies, humans intensively tend to cooperate with their closer friends, because they have to distribute their limited resources through cooperation (e.g., time, food, etc.). It also makes the situation difficult to have uniform social relationships (social grooming) with all friends. Thus, the social ...

Journal: :محیط زیست طبیعی 0
منصوره ملکیان گروه محیط زیست دانشکدۀ منابع طبیعی، دانشگاه صنعتی اصفهان راحله باقری کارشناس محیط زیست استان کهگیلویه و بویراحمد

investigating species diversity and richness is essential for defining conservation priorities. in addition, determining landscape parameters influencing species diversity and richness is important for selecting and designing parks and protected areas. kohgiluyeh & boyer ahmad province is a mountainous region, comprises hills, mounds, forests and plains. this vast province has high species dive...

Journal: :محیط شناسی 0
محمود رضا همامی دانشگاه صنعتی اصفهان ، دانشکدة منایع طبیعی، استادیار گروه محیط زیست آزاده زائری امیرانی دانشگاه صنعتی اصفهان ، دانشکدة منابع طبیعی، کارشناس ارشد محیط زیست

city parks play an important role in the welfare of metropolitan people. higher species richness of birds can be considered as a reflection of the health of the park and may satisfy visitors to a higher extent being in a more natural environment. we studied the influence of area and shape of city parks on bird species richness and diversity. 13 parks from among the 35 main city parks in isfahan...

Journal: :European Journal of Combinatorics 2009

باقری, علیرضا , بنایان اول, محمد, شافنر, اورس, قربانی, رضا,

Considering the importance of plant diversity and to evaluate the effect of grazing pressure on species richness and structure of plant communities, this experiment was conducted at Golestan National Park and its surrounding areas in the north east of Iran. Sampling was conducted in intact and abandoned habitats and habitats under seasonal and heavy grazing, using Modified Whitaker Plot in 1, 1...

Journal: :مرتع و آبخیزداری 0
قدرت اله حیدری استادیار دانشکدة منابع طبیعی دانشگاه علوم کشاورزی و منابع طبیعی ساری حمید رضا سعیدی گراغانی دانشجوی دکتری مرتع داری دانشگاه تهران

assessment of diversity and species richness in the understanding of ecosystem functions, protect and preserve genetic resources, evaluation and control of environmental change and the success or failure will help natural resource management programs. arbitrary banning livestock grazing program and one of the most common and perhaps the most degraded pastures and reduced the diversity and speci...

Journal: :بوم شناسی کشاورزی 0
آرش قلعه گلاب بهبهانی مهدی نصیری محلاتی رضا کشاورز افشار علی علی پور جهانگیری علیرضا پازکی حسام صفا محمد کریمی نژاد

biodiversity refers to all forms of living animals, plants and microorganisms and agro-biodiversity is a component of biodiversity that represents diversity in arable lands. the aim of this study was to determine the biodiversity status of agro-ecosystems of shahr-e-rey city located in south of tehran, through calculating species richness index using rarefaction method. to the collect required ...

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