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Grassland Degradation (grassland + degradation)

Distribution by Scientific Domains

Life Sciences	28%

Selected Abstracts

Alpine grassland degradation and its control in the source region of the Yangtze and Yellow Rivers, China

GRASSLAND SCIENCE, Issue 3 2005
Huakun Zhou
Abstract Serious grassland degradation is endangering the environment of the source regions of the Yangtze and Yellow Rivers (SRYYR). There is an urgent need to analyze and review the grassland resources, status of grassland degradation, factors causing grassland degradation, and measures for grassland protection and restoration so as to ensure sustainable development in the SRYYR. This review shows that: (1) The alpine meadow, one of the most important grassland types in the SRYYR, can be divided into four subtypes: typical alpine meadow, alpine swamp meadow, alpine steppe meadow and alpine shrub meadow. (2) There is approximately 357.13 × 104 ha degraded grassland in this area, which is 34.34% of the area of all the investigated grasslands in the SRYYR, and heavily degraded grasslands cover an area of 74.34 × 104 ha, approximately 20.82% of the degraded grasslands. (3) Alpine grassland degradation in the SRYYR follows the following sequence: non-degraded grassland , lightly degraded grassland , moderately degraded grassland , heavily degraded grassland. (4) Grassland degradation in the SRYYR is caused by the integrated effect of anthropogenic and natural factors. The principal factors causing grassland degradation are thought to be long-term overgrazing and the destruction by rodents that follows, and climate warming, which accelerates the grassland degradation process. (5) Some effective management practices (e.g. rodent and ruderal weed control, establishment of artificial grassland, rational management of grassland, and optimizing livestock structure) and integrated countermeasures for the restoration of degraded grasslands have been developed in the SRYYR. [source]

Soil organic carbon stocks in China and changes from 1980s to 2000s

GLOBAL CHANGE BIOLOGY, Issue 9 2007
ZUBIN XIE
Abstract The estimation of the size and changes of soil organic carbon (SOC) stocks is of great importance for decision makers to adopt proper measures to protect soils and to develop strategies for mitigation of greenhouse gases. In this paper, soil data from the Second State Soil Survey of China (SSSSC) conducted in the early 1980s and data published in the last 5 years were used to estimate the size of SOC stocks over the whole profile and their changes in China in last 20 years. Soils were identified as paddy, upland, forest, grassland or waste-land soils and an improved soil bulk density estimation method was used to estimate missing bulk density data. In the early 1980s, total SOC stocks were estimated at 89.61 Pg (1 Pg=103 Tg=1015 g) in China's 870.94 Mha terrestrial areas covered by 2473 soil series. In the paddy, upland, forest and grassland soils the respective total SOC stocks were 2.91 Pg on 29.87 Mha, 10.07 Pg on 125.89 Mha, 34.23 Pg on 249.32 Mha and 37.71 Pg on 278.51 Mha, respectively. The SOC density of the surface layer ranged from 3.5 Mg ha,1 in Gray Desery grassland soils to 252.6 Mg ha,1 in Mountain Meadow forest soils. The average area-weighted total SOC density in paddy soils (97.6 Mg ha,1) was higher than that in upland soils (80 Mg ha,1). Soils under forest (137.3 Mg ha,1) had a similar average area-weighted total SOC density as those under grassland (135.4 Mg ha,1). The annual estimated SOC accumulation rates in farmland and forest soils in the last 20 years were 23.61 and 11.72 Tg, respectively, leading to increases of 0.472 and 0.234 Pg SOC in farmland and forest areas, respectively. In contrast, SOC under grassland declined by 3.56 Pg due to the grassland degradation over this period. The resulting estimated net SOC loss in China's soils over the last 20 years was 2.86 Pg. The documented SOC accumulation in farmland and forest soils could thus not compensate for the loss of SOC in grassland soils in the last 20 years. There were, however, large regional differences: Soils in China's South and Eastern parts acted mainly as C sinks, increasing their average topsoil SOC by 132 and 145 Tg, respectively. In contrast, in the Northwest, Northeast, Inner Mongolia and Tibet significant losses of 1.38, 0.21, 0.49 and 1.01 Pg of SOC, respectively, were estimated over the last 20 years. These results highlight the importance to take measures to protect grassland and to improve management practices to increase C sequestration in farmland and forest soils. [source]

Alpine grassland degradation and its control in the source region of the Yangtze and Yellow Rivers, China

The grassland farming system and sustainable agricultural development in China

GRASSLAND SCIENCE, Issue 1 2005
Zhibiao Nan
Abstract Grassland is the largest terrestrial ecosystem in China, at about 39 280 × 104 ha and covers 41% of the total land area. Grasslands not only provide forage to feed livestock, but also play a critical role in alleviating many of the most challenging environmental and ecological problems that humankind is facing. About 90% of the total usable grassland in China has been degraded to various extents and this is the number one problem facing agricultural production, rural development and environmental improvement. Research on grassland degradation has been carried out since the early 1950s. Enormous achievements have been made and theory and a technical system for pastoral agriculture have been developed. This pastoral agriculture system is a well-organized modern farming system including four production levels, that is, preplant, plant, animal and postbiotic levels, and is linked by three interfaces, including vegetation-site, grassland-animal and production-management. The system capacity and productivity could be improved by system coupling. Since it emerged, this pastoral agriculture system has been established in various ecological regions in China and significant improvements in agricultural sustainability, farmer's income and environmental stability have been obtained. In the future, it will play a more critical role in developing sustainable agriculture in China. [source]

Significant Achievements in Protection and Restoration of Alpine Grassland Ecosystem in Northern Tibet, China

RESTORATION ECOLOGY, Issue 3 2009
Qing-zhu Gao
Abstract Alpine grassland is a fragile ecosystem, and a large area of this grassland type has been severely degraded in Northern Tibet, to the extent that it has become the primary ecological problem in the region. Various levels of government, including the national central government, the Tibetan Autonomous Region government, and the Nagqu Prefecture government have worked together to achieve alpine grassland ecosystem protection and prevent grassland degradation. These efforts have resulted in significant ecological, social, and economic benefits in Northern Tibet. [source]