نتایج جستجو برای: content richness

تعداد نتایج: 434052  

Journal: :J. Information Science 2014
Jinhee Park Jaekwang Kim Jee-Hyong Lee

In this paper, a method is proposed to extract topic keywords of blogs, based on the richness of content. If a blog includes rich content related to a topic word, the word can be considered as a keyword of the blog. For this purpose, a new measure, richness, is proposed, which indicates how much a blog covers the trendy subtopics of a keyword. In order to obtain trendy subtopics of keywords, we...

2009
Helmut Hillebrand Lars Gamfeldt Per R. Jonsson Birte Matthiessen

Ecological stoichiometry can be a powerful tool to understand food web consequences of altered biogeochemical cycles as well as consequences of biodiversity loss on biogeochemistry and has proved to be a suitable framework to predict effects of consumers on the nutrient content of their prey. However, predictions from ecological stoichiometry have mainly been tested using single consumer specie...

2006
Stefan Panama Laube Gerhard Zotz

Question: What are the qualitative and quantitative long-term changes in the vascular epiphyte assemblage on a particular host tree species? Location: Lowland rain forest of the San Lorenzo Crane Plot, Republic of Panama. Methods: We followed the fate of the vascular epiphyte assemblage on 99 individuals of the palm Socratea exorrhiza by three censuses over the course of five years. Results: Th...

2012
Lauren B. Buckley Allen H. Hurlbert Walter Jetz

Results The differences in thermal physiology between ectotherms and endotherms result in geographically disparate macrophysiological constraints. Field metabolic rate (FMR) is stable or decreases slightly with temperature for endotherms, while it generally increases for ectotherms, leading to opposing latitudinal gradients of expected FMR. Potential activity time is a greater constraint on the...

Journal: :Environmental pollution 2011
Carly J Stevens Cecilia Duprè Edu Dorland Cassandre Gaudnik David J G Gowing Albert Bleeker Martin Diekmann Didier Alard Roland Bobbink David Fowler Emmanuel Corcket J Owen Mountford Vigdis Vandvik Per Arild Aarrestad Serge Muller Nancy B Dise

A survey of 153 acid grasslands from the Atlantic biogeographic region of Europe indicates that chronic nitrogen deposition is changing plant species composition and soil and plant-tissue chemistry. Across the deposition gradient (2-44 kg N ha(-1) yr(-1)) grass richness as a proportion of total species richness increased whereas forb richness decreased. Soil C:N ratio increased, but soil extrac...

Journal: :The Science of the total environment 2012
Anna M Stefanowicz Paweł Kapusta Grażyna Szarek-Łukaszewska Krystyna Grodzińska Maria Niklińska Rolf D Vogt

This study examined the effects of soil physicochemical properties (including heavy metal pollution) and vegetation parameters on soil basal respiration, microbial biomass, and the activity and functional richness of culturable soil bacteria and fungi. In a zinc and lead mining area (S Poland), 49 sites were selected to represent all common plant communities and comprise the area's diverse soil...

2008
Ranjeet John Jiquan Chen Nan Lu Ke Guo Cunzhu Liang Yafen Wei Asko Noormets Keping Ma Xingguo Han

Changes in species composition and diversity are the inevitable consequences of climate change, as well as land use and land cover change. Predicting species richness at regional spatial scales using remotely sensed biophysical variables has emerged as a viable mechanism for monitoring species distribution. In this study, we evaluate the utility ofMODIS-based productivity (GPP and EVI) and surf...

ژورنال: علوم آب و خاک 2010
نصیری محلاتی, مهدی , خداشناس, علیرضا , رضوانی مقدم, پرویز , لکزیان, امیر , کوچکی, علیرضا ,

Among the biodiversity of soil microorganisms, bacteria have the basic role in soil functions. In order to determine the diversity and abundance of soil bacteria in arid regions, and also to study the effect of agricultural practices on them, a study was conducted in winter wheat fields on Shirvan, Mashhad and Gonabad. In each region, high and low input fields of winter wheat and a natural syst...

2016
André S J van Proosdij Niels Raes Jan J Wieringa Marc S M Sosef

In conservation studies, solely widespread species are often used as indicators of diversity patterns, but narrow-ranged species can show different patterns. Here, we assess how well subsets of narrow-ranged, widespread or randomly selected plant species represent patterns of species richness and weighted endemism in Gabon, tropical Africa. Specifically, we assess the effect of using different ...

2013
Ximei Zhang Guangming Zhang Quansheng Chen Xingguo Han

Climate warming and shifting precipitation regimes are affecting biodiversity and ecosystem functioning. Most studies have focused on the influence of warming and altered precipitation on macro-organisms, whereas the responses of soil microbial communities have been neglected. We studied the changes in the abundance, richness, and composition of the entire bacterial kingdom and 16 dominant bact...

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