نتایج جستجو برای: semi arid environments

تعداد نتایج: 336433  

2016
Yao Zhang Xiangming Xiao Luis Guanter Sha Zhou Philippe Ciais Joanna Joiner Stephen Sitch Xiaocui Wu Julia Nabel Jinwei Dong Etsushi Kato Atul K. Jain Andy Wiltshire Benjamin D. Stocker

Carbon uptake by terrestrial ecosystems is increasing along with the rising of atmospheric CO2 concentration. Embedded in this trend, recent studies suggested that the interannual variability (IAV) of global carbon fluxes may be dominated by semi-arid ecosystems, but the underlying mechanisms of this high variability in these specific regions are not well known. Here we derive an ensemble of gr...

Journal: :Remote Sensing 2022

Vegetation cover change is one of the key indicators used for monitoring environmental quality. It can accurately reflect changes in hydrology, climate, and human activities, especially arid semi-arid regions. The main goal this paper to review remote sensing satellite sensors methods mapping vegetation semi-arid. Arid lands are eco-sensitive environments with limited water resources cover. Mon...

Journal: :desert 2015
amir reza keshtkar

knowledge about low flow statistics is essential for effective water resource planning and management in ungauged orpoorly gauged catchment areas, especially in arid and semi-arid regions such as iran. we employed a data set of 20 riverflow time-series from the iranian central plateau river basin, iran to evaluate the low-flow series using several frequencyanalysis methods and compared the resu...

Journal: :journal of rangeland science 2014
mohsen sharafatmandrad adel sepehry hossein barani

in arid and semi-arid rangelands, grazing as one of the natural or human induced processes has direct and indirect effects on structure and dynamics of plant community and ecosystems. a study was done to analyze the effects of grazing on plant species diversity and plant functional types‘ (pfts) diversity of arid and semi-arid rangelands. we analyzed plant richness and diversity data from 75 sa...

Journal: :journal of rangeland science 2011
nasrin kolahchi mohsen mohseni saravi ali tavili mohammad jafari ghasem assadian

at the beginning of twenty-first century, the water crisis in the priority policy andmanagement is inside and outside of the country as principle thoroughly human, social,economic and political rulers of the country is considered abundant. the world bank hasannounced that during 1960 and 2025, water resources in middle east, from 3430 m3 for theeach person in year reach to 667 m3 because of pop...

Journal: :journal of rangeland science 2012
sedigheh zare kia hossein arzani mohammad jafari seyyed akbar javadi ali ashraf jafari

this study aims to assess the effect of grazing intensity on vegetation structure, soil nutrient concentrations and soil physical properties. the study was carried out in steppe rangelands of saveh, markazi province, iran. four sites with four grazing intensities including very high, high, moderate and non-grazed with the same ecological conditions were selected. to study various vegetation and...

Journal: :Mesopotamia Journal of Agriculture 2005

Journal: :caspian journal of environmental sciences 2008
m. b. hiremath a. josephrajkumar v. mukund r. ramesh p. k. shetty

studies of rainfall variation generally focus on large areas. for example, in india, the area average monsoon rainfall series of the whole country or meteorological subdivisions are used. this would be of no use for local agriculture, particularly in places where rainfall is very high or very low, especially for crops like small cardamom and vanilla which are very sensitive to soil moisture and...

2016
Aaron M Foley David G Hewitt Charles A DeYoung Randy W DeYoung Matthew J Schnupp

White-tailed deer are a culturally and economically important game species in North America, especially in South Texas. The recent discovery of chronic wasting disease (CWD) in captive deer facilities in Texas has increased concern about the potential emergence of CWD in free-ranging deer. The concern is exacerbated because much of the South Texas region is a semi-arid environment with variable...

2012
Arantzazu L. Luzuriaga Ana M. Sánchez Fernando T. Maestre Adrián Escudero

The study of species coexistence and community assembly has been a hot topic in ecology for decades. Disentangling the hierarchical role of abiotic and biotic filters is crucial to understand community assembly processes. The most critical environmental factor in semi-arid environments is known to be water availability, and perennials are usually described as nurses that create milder local con...

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