نتایج جستجو برای: steppe rangeland in karsanak region

تعداد نتایج: 17017216  

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

growing demands and requires of high data rate systems cause significant increase of high frequency systems for wideband communication applications. as mixers are one of the main blocks of each receivers and its performance has great impact on receiver’s performance; in this thesis, a new solution for ku-band (12-18 ghz) mixer design in tsmc 0.18 µm is presented. this mixer has high linearity a...

2011
Gang Dong Jixun Guo Jiquan Chen Ge Sun Song Gao Liangjun Hu Yunlong Wang

Global climate change projections suggest an increasing frequency of droughts and extreme rain events in the steppes of the Eurasian region. Using the eddy covariance method, we measured carbon and water balances of a meadow steppe ecosystem in Northeast China during 2 years which had contrasting precipitation patterns in spring seasons in 2007 and 2008. The meadow steppe sequestrated only 64Ð2...

Journal: :Remote Sensing 2017
Sheng Chang Bingfang Wu Nana Yan Bulgan Davdai Elbegjargal Nasanbat

In Mongolia, drought is a major natural disaster that can influence and devastate large regions, reduce livestock production, cause economic damage, and accelerate desertification in association with destructive human activities. The objective of this article is to determine the optimal satellite-derived drought indices for accurate and real-time expression of grassland drought in Mongolia. Fir...

Preference value means livestock preference to eat some plants relative to other plants or species. Accordingly, by studying the preference values, the range managers could determine the rangelands grazing capacity to achieve the optimum performance of livestock and to guarantee the stability of rangeland ecosystem. The objective of this study was to determine the preference value of perennial ...

Journal: :desert 2008
n. baghestani-maybodi m. jankju-borzelabad m. taghi zare

one of the key factors in managing a rangeland is to determine the relative preference of its major plant species by thegrazing livestock. preference value of each plant species is affected by plant type, companion plants, availability byanimals, phenological stage, climate condition, and the livestock species. we investigated the grazing behaviour of anative goat (garizi) in the steppe rangela...

2017
Yi-Feng Yao Xiao-Yan Song Alexandra H. Wortley Yu-Fei Wang Stephen Blackmore Cheng-Sen Li

The Hengduan Mountains, with a distinct altitudinal differentiation and strong vertical vegetation zonation, occupy an important position in southwestern China as a global hotspot of biodiversity. Pollen analysis of lake sediments sampled along an altitudinal gradient in this region helps us to understand how this vegetation zonation arose and how it has responded to climate change and human im...

2008
Yan Zhao Zicheng Yu Fahu Chen

Pollen data from 30 sites in arid and semi-arid regions of China were reviewed to document regional patterns of Holocene vegetation and climate change and to understand the large-scale controls on these changes. Vegetation at most sites in eastern Inner Mongolia switched between forest, forest steppe, and typical steppe, showing maximum moisture conditions before 6 ka (1 ka 1⁄4 1000 cal yr BP) ...

Journal: :journal of rangeland science 0
mohsen sharafatmandrad natural resources department, rangeland and watershed management section, university of jiroft, jiroft, iran hossein naderi faculty of rangeland and watershed management, gorgan university of agricultural sciences and natural resources

biodiversity plays a crucial role in stability and productivity of natural ecosystem. the main goal of this research was to classify ecological groups in steppe rangeland and investigate their relationships with plant diversity indices. therefore, fifty different land unit tracts (lut) were identified in khod-neuk basin, yazd province, iran, in 2010. vegetation and soil samples were taken in th...

2015
Guoqing Li Zhongming Wen Ke Guo Sune Linder Eric J. Jokela

A risk assessment of vegetation zone responses to climate change was conducted using the classical Holdridge life zone model on the Loess Plateau of Northwest China. The results show that there are currently ten vegetation zones occurring on the Loess Plateau (1950–2000), including alvar desert, alpine wet tundra, alpine rain tundra, boreal moist forest, boreal wet forest, cool temperate desert...

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