نتایج جستجو برای: arid environment condition

تعداد نتایج: 833368  

2015
Wenli Quan Xun Liu Haiqing Wang Zhulong Chan

Drought is one of major environmental determinants of plant growth and productivity. Alfalfa (Medicago sativa) is a legume perennial forage crop native to the arid and semi-arid environment, which is an ideal candidate to study the biochemical and molecular mechanisms conferring drought resistance in plants. In this study, drought stress responses of two alfalfa varieties, Longdong and Algonqui...

Journal: :journal of rangeland science 2013
ezatollah moradi gholam ali heshmati ali hosein bahramian

rangeland health assessment provides qualitative information on ecosystemattributes. we examined changes in rangeland health in the zagros semi-arid rangelands ofiran at fixed sites between 2001 and 2011, over the 10-year period. the rangelandfragments significantly declines in the quality of the vegetation, and changes in plantspecies were driven largely by seasonality, and to a lesser extent,...

2005
S. Vetter

This paper reviews the predictions and management implications of two current paradigms in the ecology and management of arid and semi-arid rangelands. The equilibrium model stresses the importance of biotic feedbacks such as density-dependent regulation of livestock populations and the feedback of livestock density on vegetation composition, cover and productivity. Range management under this ...

1997
Anson E. Thompson

Relatively little research has been expended on developing plants for use in urban desert landscapes or “xeriscapes.” However, because of reduced availability and increased cost of water, water conservation needs, and concerns for our environment, increased awareness and demand for arid-adapted landscape plants have developed. An especially important need is for groundcover requiring little wat...

2004
P. N. Macharia

A research study was conducted in Mashuru Division of Kajiado District, Kenya with the objective of analyzing the types of vegetation degradation, their causes and their influence on rangeland condition and trend. The study was conducted through remote sensing tools, ground truthing, interviews, community workshop and literature. The results of the study showed that excessive use of the woody s...

Journal: :نشریه علمی - پژوهشی هیدرولوژی کاربردی 0
mohammad mirzavand kashan university seyyed javad sadatinejad tehran university hoda ghasemieh kashan university mahmud akbari kashan university hanifreza motamed shariati tehran university

in arid and semi-arid environments, groundwater plays a significant role in the ecosystem. in the last decades, groundwater levels have decreased due to the increasing demand for water, weak irrigation management and soil damage. for the effective management of groundwater, it is important to model and predict fluctuations in groundwater levels. in this study, groundwater table in kashan plain ...

Journal: Desert 2013
A. Mataji M. Bihamta M. Jafari M. Mousaei Sanjerehei N. Baghestani Meybodi

The purpose of this study was to evaluate the species-environment relationships in arid and semi-arid rangelandsof Nodushan, Yazd. The plant species cover and the environmental variables were measured at 9 sites. Soil sampleswere taken for measurement of 12 attributes in 0-10 cm and 10-80 cm layers. Vegetation was classified using twowayindicator species analysis (TWINSPAN). Data was analyzed u...

2002
RICHARD H. WARING NICHOLAS C. COOPS JANET L. OHMANN DANIEL A. SARR

In forested portions of Oregon, species richness of woody plants on plots 400–500 m2 ranged from 1 to .20. We investigated what might account for this variation using a satellite-driven process model that predicts gross photosynthesis and establishes, on a monthly time step, the most constraining environmental variable. Independent satellite and ground-based data confirmed that the highest spec...

Journal: :Journal of Arid Environments 2021

Precipitation affects large herbivore performance, but data is often available from only a limited number of weather stations that may not correspond with home ranges. Remotely-sensed estimates could potentially address this by providing precipitation at any point on the landscape. We tested whether 4-km resolution derived Parameter-elevation Relationships Independent Slopes Model (PRISM) were ...

Journal: :Environment and Planning A: Economy and Space 2001

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