نتایج جستجو برای: rangeland biodiversity

تعداد نتایج: 39455  

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...

2010
Jonathan B. Thayn Kevin P. Price Randall B. Boone

We examine relationships between landscape scale measurements of rangeland complexity and cattle stocking rates in Kansas. Rangeland complexity was characterized using Advanced Very High Resolution Radiometer (AVHRR) satellite imagery and the USGS National Land Cover Dataset (NLCD). Satellite Normalized Difference Vegetation Index (NDVI) values were summed over the 2002 growing-season and then ...

2006
Brandon T. Bestelmeyer

Ecological thresholds describe abrupt changes in ecological properties in time or space. In rangeland management, thresholds reflect changes in vegetation and soils that are expensive or impossible to reverse. The threshold concept has catalyzed important advances in rangeland management thinking, but it has also introduced two classes of drawbacks. First, the ambiguity of the term ‘‘threshold’...

2014
Aida López-Sánchez John Schroeder Sonia Roig Mar Sobral Rodolfo Dirzo

Oak woodlands of Mediterranean ecosystems, a major component of biodiversity hotspots in Europe and North America, have undergone significant land-use change in recent centuries, including an increase in grazing intensity due to the widespread presence of cattle. Simultaneously, a decrease in oak regeneration has been observed, suggesting a link between cattle grazing intensity and limited oak ...

2017
Ru An Hui-Lin Wang Xue-Zhi Feng Zhe Wang Ying Wang Ying-Hui Zhao

the “Three-River Headwaters” region (TRHR) rangeland ecosystem is extremely sensitive and fragile, and in recent years has undergone continuous degradation. The vast area and severe nature conditions inhibit data acquisition and field experiments, resulting in different understandings about the spatial characteristics and dynamics of rangeland degradation in the region. Therefore, reliable moni...

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...

Mohammad Hasan Jouri Soode Miarrostami

Overgrazing, via harvesting of forage species and decrease the other herbs, is of progressive factors in biodiversity destroying. In order to investigate the animal grazing impacts on changing of plant structure and diversity, we selected the comparison between this effect with exclosure area, and proving of the excluded area effects on plant diversity; two sites of Kojour rangeland, Mazandran ...

Journal: :journal of rangeland science 2012
soode miarrostami mohammad hasan jouri

overgrazing, via harvesting of forage species and decrease the other herbs, is of progressive factors in biodiversity destroying. in order to investigate the animal grazing impacts on changing of plant structure and diversity, we selected the comparison between this effect with exclosure area, and proving of the excluded area effects on plant diversity; two sites of kojour rangeland, mazandran ...

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