نتایج جستجو برای: steppe rangelands

تعداد نتایج: 6506  

2008
J. G. Han Y. J. Zhang C. J. Wang W. M. Bai Y. R. Wang G. D. Han L. H. Li

Rangelands of China have for centuries provided forage for livestock but now their role in water, soil, and biodiversity conservation is being recognised by Governments and people. However, much of the rangelands has recently degraded anddesertification is nowawidespread problem.The cause of the degradation is over-grazing andover-cultivation. Climate change is exacerbating theproblem.TheChines...

2004
Charles Perrings Brian Walker

In previous papers we have considered the optimal mix of biodiversity in semi-arid rangelands, focusing on the steady state. This paper addresses the question of conservation in the optimal use of rangelands, where conservation is understood to mean maintenance of the system in a ‘natural’ state. We consider a rangeland that may exist in one of two states. In the ‘natural’ state, its dynamics a...

2011
S. H. Kaboli

The evaluation of vegetation covers using conventional methods is difficult over arid areas due to several reasons such as lack of the suitable roads to these regions. Moreover, this task is time-consuming. For these reasons, remote sensing has been considered as an economic alternative for conventional field work. In this study, the feasibility of using IRS images in vegetation cover evaluatio...

2007
W. L. Zhang S. P. Chen J. Chen L. Wei

An increasing amount of grasslands in Inner Mongolia of Northern China has been converted to cropland. The conversions in this extensive semiarid region have produced adverse ecological consequences at local and regional scales (e.g., dust storms). An important research need is to understand the fundamental ecosystem processes, such as energy and material fluxes, associated with the land conver...

2012
Yu Wang Guangsheng Zhou

Vegetation light use efficiency (LUE) is a key parameter of Production Efficiency Models (PEMs) for simulating gross primary production (GPP) of vegetation, from regional to global scales. Previous studies suggest that grasslands have the largest inter-site variation of LUE and controlling factors of grassland LUE differ from those of other biomes, since grasslands are usually water-limited eco...

2009
Haixia Miao Shiping Chen Jiquan Chen Wenli Zhang Ping Zhang Long Wei Xingguo Han Guanghui Lin

To examine the effects of cultivation and grazing on evapotranspiration (ET), continuous measurements of ET were conducted over almost two years, from December 2005 to September 2007, using the eddycovariance technique in two paired ecosystems: a steppe and a cropland in Duolun and a fenced and a degraded steppe in Xilinhot, Inner Mongolia, China. The ET of the four ecosystems approached or exc...

2016
Zhiqiang Wan Jiuyan Yang Rui Gu Yan Liang Yulong Yan Qingzhu Gao Jie Yang Fausto Cavallero

The Stipa grandis steppe is a type of steppe in the Central Asian sub-region, and it is an important resource for livestock production in China. Mowing is one of the main management methods for this steppe. Verifying the response of the Stipa grandis steppe communities to different mowing frequencies is essential for the rational utilization of pastures and the protection and recovery of natura...

2012
Mohammad Mousaei Sanjerehei

The objective of this research was to identify the vegetation-soil relationships in Nodushan arid rangelands of Yazd. 5 sites were selected for measuring the cover of plant species and soil attributes. Soil samples were taken in 0-10 and 10-80 cm layers. The species studied were Salsola tomentosa, Salsola arbuscula, Peganum harmala, Zygophylum eurypterum and Eurotia ceratoides. Canonical corres...

2007
William J. Elliot Peter R. Robichaud I. Sue Miller

Abstract. In both forest and rangelands, fuel reduction operations are now common practices. Mechanical thinning followed by prescribed fire is common in forests, while fire is frequently applied to rangelands. Studies at different scales (50 sq m to 389 ha) measure the erosion from fuel management. This presentation compares runoff and erosion from these studies. Plot size has the greatest inf...

2017
Torsten Wronski Jean Damascene Bariyanga Ping Sun Martin Plath Ann Apio

Lantana camara L. (Verbenaceae) originates from tropical Central and South America and has become invasive in about 50 countries. It causes problems when invading rangelands due to its toxicity to livestock and its tendency to form dense, monotonous thickets. Its invasiveness can partly be explained by the high tannin content largely protecting the species from being browsed, its tolerance to a...

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