نتایج جستجو برای: arid area therefore
تعداد نتایج: 1171562 فیلتر نتایج به سال:
In arid and semi-arid environments like the rest parts of South Africa, the state of vegetation density in catchments is an important indicator of the state of the environment. Climate variability coupled with different anthropogenic activities could affect vegetation cover at varying levels. The Upper Molopo River Catchment (UMRC) in the North West Province of South Africa is under this combin...
One of the most important calamities that affect the arid and semi- arid regions and is taken into account as threatening factors for human- life and destroying the natural resources is desertification, so recognizing and forecasting this phenomenon is very important. Desertification is a complex phenomenon, which as environmental, socio-economical, and cultural impacts on natural resources. In...
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...
Aim In this study, we examine patterns of local and regional ant species richness along three elevational gradients in an arid ecosystem. In addition, we test the hypothesis that changes in ant species richness with elevation are related to elevation-dependent changes in climate and available area. Location Spring Mountains, Nevada, U.S.A. Methods We used pitfall traps placed at each 100-m elev...
Since 1990 the project ‘Climate Change in the Arid Andes’ has been focusing on past climate and environmental conditions in the high mountain range of the north Chilean Andes (18 S– 28 S). The extreme aridity of this region is shown by the absence of glaciers, even at the highest altitudes above 6700 m a.s.l. More knowledge of the present climatic situation is needed to interpret the proxy data...
Israel is a small country with a total land area of 21,000 km, from which 20% is arable land. More than half of Israel has an arid to semi-arid climate. Approximately half of the cultivated area (200,000 hectares) has to be irrigated due to lack of rainfall and other water resources. Approximately 80% of the irrigated land in Israel uses the fertigation method, combining the application of wate...
Interactive Digital Television (iDTV) has facilitated and expanded the communication and interaction in activities of knowledge acquisitions, entertainment, and recreation in the distance learning field. This new way of teaching and learning has been called t-Learning. In this context, the Learning Objects (LOs) have an important role in assisting in the electronic courses’ development. Due the...
The atmospheric movement of arid soil can play an important role in the movement of microorganisms attached to soil microparticles. Bacterial community structures in Asian dust collected at Beijing were investigated using the 16S rRNA gene sequence and compared to those in arid soil, a possible source of the dust. Asian dust samples contained 2.5×10(7) to 3.5×10(9) copies of the 16S rRNA gene g...
Out of about 1.2 billion people in India, 68% people live on agriculture as their main occupation. Ground water is therefore an important resource which provides over 70% of rural drinking water supply and about 50% of water used for irrigation. Rains in Monsoon season from June to September, provide the main source of water but they last only for four months and the rest of the year is dry in ...
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