نتایج جستجو برای: especially in arid and semi

تعداد نتایج: 21760562  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده فنی مهندسی 1385

acknowledge the importance of e-commerce to their countries and to survival of their businesses and in creating and encouraging an atmosphere for the wide adoption and success of e-commerce in the long term. the investment for implementing e-commerce in the public sector is one of the areas which is focused in government‘s action plan for cross-disciplinary it development and e-readiness in go...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تربیت مدرس - دانشکده علوم پزشکی 1389

introduction: diabetes mellitus is an growing national and international public health concern. the number of people affected by diabetes in world by 2030 will be 69% in developing countries. regular physical activity plays a key role in the management of type 2 diabetes melitus, particularly glycemic control. it has been recommended that peoples with type 2 diabetes participate in moderate-int...

Journal: :Journal of environmental biology 2011
S Gnaana Saraswathi Kailash Paliwal

Seasonal changes in soil respiration (SR), soil temperature (ST) and soil moisture (SM) were compared between a barren land with no vegetation (control) and grassland dominated by Heteropogon contortus (L.) of a semi-arid eco-system during 2005-2006. A statistically significant (p<0.001) seasonal change in SR was observed between the two sites. The variation characteristics of soil CO2 effiux r...

2015
Li-Na Xie Hong-Yu Guo Christopher A. Gabler Qing-Fang Li Cheng-Cang Ma

Few studies have investigated the influence of water availability on plant population spatial patterns. We studied changes in the spatial patterns of Caragana stenophylla along a climatic drought gradient within the Inner Mongolian Plateau, China. We examined spatial patterns, seed density, "nurse effects" of shrubs on seedlings, transpiration rates and water use efficiency (WUE) of C. stenophy...

Journal: Desert 2017
H.R. Karimzadeh J. Pourrezaei M. Tarkesh Esfahani M.R. Vahabi S.J. Khajeddin V. Mozaffarian

     Roads have an important role in plants dispersal on different scales. Various plant species settle on roadsides, but some of them can enter the natural environments and threaten their biodiversity. Worldwide knowledge of roadside flora is necessary for local and global management of natural areas. Accordingly, the roadside flora of Northern Khorasan rangelands was studied along the 600 km ...

Severe range degradation was critically extended in many region of Iran and caused many rangelands were restricted and interwoven with croplands in a complex system. Therefore, rangeland planning and inventory as an isolated activity has become almost impossible. Current landscape planning involves contributions of different social organizations often with different interests and with different...

Ali Tavili, Ghasem Assadian Mohammad Jafari Mohsen Mohseni Saravi, Nasrin kolahchi

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...

2010
S. Er-Raki A. Chehbouni V. Simonneaux R. Allen

In this study, the performance of three empirical methods for estimating reference evapotranspiration (ET0): Makkink (Mak) and PriestleyeTaylor (PT) (radiation-based) and HargreaveseSamani (HARG) (temperature-based) were assessed in semi-arid regions. The values of ET0 derived using these three methods were compared to those estimated using the reference FAO PenmaneMonteith (FAO-PM) method unde...

2001
M. S. Krol

Northeastern Brazil, an example of vulnerable semi-arid regions on the earth, is characterised by water scarcity and vulnerability of .natural resources, pronounced climatic variability and social stress situations. Integrated studies involving hydrology, ecology, meteorology, climatology, pedology, agronomy, and social and economic sciences are required not only for analysing consequences of t...

2006
Vroni Retzer

Understanding the dynamics of semi-arid rangelands is a prerequisite for their proper management and long-term enclosure experiments are an important tool to investigate grazing impact. Hein (2006) presents findings from a 10 year enclosure experiment in the semi-arid Ferlo, Senegal. His main conclusion is that current high grazing pressure (0.15–0.20 TLU/h) negatively affects rain use efficien...

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