نتایج جستجو برای: steppic rangelands

تعداد نتایج: 2416  

2008
E. G. King

Livestock overgrazing can threaten the ecological integrity of rangelands, and can also threaten the sustainability of pastoralist societies who depend on rangelands for their livelihood. Using facilitator plants in the restoration of degraded semi-arid rangelands offers a promising strategy because in such environments, facilitators can ameliorate harsh conditions that often limit the establis...

Journal: :Environmental pollution 2002
G E Schuma H H Janzen J E Herrick

The USA has about 336 Mha of grazing lands of which rangelands account for 48%. Changes in rangeland soil C can occur in response to a wide range of management and environmental factors. Grazing, fire, and fertilization have been shown to affect soil C storage in rangelands, as has converting marginal croplands into grasslands. Carbon losses due to soil erosion can influence soil C storage on r...

Journal: :Bulletin of the Ecological Society of America 2006

2016
Hua Liu Runguo Zang Han Y. H. Chen

Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respirati...

2011
K. J. Wessels R. Mathieu

People in the rural, communal areas of South Africa rely on live fuel wood for more than 90% of their energy requirements. Using airborne lidar from the Carnegie Airborne Observatory (CAO) we compared tree canopy cover and height distributions between communal landscapes with heavy utilization to fully protected public and private reserves in the Lowveld of South Africa. Rangelands and fields i...

2013
Viorel D. Popescu Laurenţiu Rozylowicz Dan Cogălniceanu Iulian Mihăiţă Niculae Adina Livia Cucu

Rapid climate change represents one of the top threats to biodiversity, causing declines and extinctions of many species. Range shifts are a key response, but in many cases are incompatible with the current extent of protected areas. In this study we used ensemble species distribution models to identify range changes for 21 reptile and 16 amphibian species in Romania for the 2020s and 2050s tim...

2006
E. Durant

_______________________________________ The 11 papers in this document address issues and needs in the development and stewardship of Central Asia rangelands, and identify directions for future work. With its vast rangelands and numerous pastoral populations, Central Asia is a region of increasing importance to rangeland scientists, managers, and pastoral development specialists. Five of the pa...

1994
T. Gauquelin G. Jalut M. Iglesias F. Valle F. Fromard

Above-ground perennial phytomass of Andalusian alfa grass steppes (7755·6 ± 1482 kg of dry matter ha (95% C.I.)) is clearly higher than phytomass density measured today in most alfa grass communities of the Maghreb because of low or inexistant present-day human-induced alterations and relatively favourable annual precipitation (370 mm) existing in these Spanish steppes. Total carbon storage mea...

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