نتایج جستجو برای: content richness

تعداد نتایج: 434052  

Journal: :بوم شناسی کشاورزی 0
اشکان عسگری کورس خوشبخت سعید صوفی زاده جعفر کامبوزیا

evaluation diversity of agricultural plants and effectiveness of management factors in non-hunting of gharaviz abstract biodiversity is the basis of agriculture. sustainable agriculture both promotes and is enhanced by biodiversity. during present study, agrobiodiversity and management factors were investigated in three villages of gharaviz area and four villages in surroundings area, in sarpol...

Journal: :بوم شناسی کشاورزی 0
فخرالدین هاشمی شادگان کوروس خوشبخت عبدالمجید مهدوی دامغانی هادی ویسی هومان لیاقتی

biodiversity is an important component in sustainability assessment of agroecosystems. along with increasing or decreasing of biodiversity, ecosystem services in agroecosystems will be varied. agricultural experts take into account different factors which affect agroecosystems variation. in this study, farming systems of two areas including a protected mountainous area and also a plain – hilly ...

Journal: :Neotropical entomology 2010
Soraia Diniz Paulo I Prado Thomas M Lewinsohn

Anthropogenic changes in the landscape result in an environmental mosaic with serious consequences for biodiversity. The aim of the present study was to assess the effects of the anthropogenic changes on Asteraceae richness and abundance, and to evaluate the consequences for the richness of Tephritidae assemblages in five sampling sites, with three sampled habitats in each: cerrado (Brazilian s...

Journal: :The American naturalist 2001
N M Haddad D Tilman J Haarstad M Ritchie J M Knops

We experimentally separated the effects of two components of plant diversity-plant species richness and plant functional group richness-on insect communities. Plant species richness and plant functional group richness had contrasting effects on insect abundances, a result we attributed to three factors. First, lower insect abundances at higher plant functional group richness were explained by a...

Journal: :محیط زیست طبیعی 0
میترا شریعتی نجف آبادی دانش آموخته کارشناسی ارشد محیط زیست، گروه شیلات و محیط زیست، دانشکده منابع طبیعی، دانشگاه تهران محمد کابلی استادیار، گروه شیلات و محیط زیست، دانشکده منابع طبیعی، دانشگاه تهران صاحبه کریمی دانشجوی کارشناسی ارشد محیط زیست، گروه شیلات و محیط زیست، دانشکده منابع طبیعی، دانشگاه تهران وحید خدایی دانش آموخته کارشناسی محیط زیست، گروه شیلات و محیط زیست، دانشکده منابع طبیعی، دانشگاه تهران سپیده شاکری دانشجوی کارشناسی ارشد مدیریت محیط زیست، گروه مدیریت و برنامه ریزی محیط زیست، دانشکده محیط زیست، دانشگاه تهران سعید محمدی دانش آموخته کارشناسی ارشد رشته علوم محیط زیست، دانشکده محیط زیست و انرژی، دانشگاه آزاد اسلامی، واحد علوم و تحقیقات تهران

hyrcanian forests in northern slope of alborz support high bird richness and abundance same as central of europe. in this study, efficiency of different methods including fixed-width transect, variable-width transect, fixed-radius point count and variable circular plot samplings were compared in order to present the most reliable methods for surveying and monitoring of diurnal forest birds in f...

Journal: :Ecology letters 2008
Susan Harrison Howard Cornell

Despite widespread acknowledgement that local ecological communities are profoundly shaped by regional-scale influences, including evolutionary and biogeographic processes, this perspective has yet to be widely incorporated into ecological research. Drawing on recent research, we propose four steps towards making regional influences a stronger part of research on the richness of local communiti...

1997
Inês Oliveira Nuno Correia Nuno Guimarães

The main motivation for extracting the content of information is the accessibility problem. A problem that is even more relevant for dynamic multimedia data, which also have to be searched and retrieved. While content extraction techniques are reasonably developed for text, video data still is essentially opaque. Its richness and complexity suggests that there is a long way to go in extracting ...

2000
Lawrence D. Bergman Vittorio Castelli Chung-Sheng Li John R. Smith

In this paper we describe the architecture and implementation of a digital library framework for scientific data, particularly imagery, with a focus on support for content-based search. Content is specified by the user at one or more of the following abstraction levels: pixel, feature, and semantic. An object-definition mechanism has been developed that supports examplebased and constraint-base...

2008
Julia Stoyanovich Sihem Amer-Yahia Cameron Marlow Cong Yu

Social tagging sites such as Flickr, YouTube and del.icio.us are becoming increasingly popular. Users of these sites annotate and endorse content by tagging, and form social ties with other users by including them into their friendship network. The richness of social context raises the users’ expectations with respect to the quality of served content, but also presents a unique opportunity for ...

الوانی نژاد, سهراب, اسماعیل زاده, امید , ذاکری پاشاکلایی, محسن,

Diversity is one of the most important issues in studies of vegetation ecology. This study was carried out in research forest of Tarbiat Modares University for surveying herbaceous and woody species diversity in relation to topographical factors (altitude, slope and aspect). For this purpose, 48 plots 400 m2 (20×20 m) were established in the region using selective sampling method. Then, the nam...

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