Analysis of current grassland resources in China
Author(s): SHEN HaiHua, ZHU YanKun, ZHAO Xia, GENG XiaoQing, GAO ShuQin, FANG JingYun, State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences
Pages: 139-154
Year: 2016 Issue: 2
Journal: Chinese Science Bulletin
Keyword: grassland area; distribution; bio-diversity; biomass; productivity; carrying capacity;
Abstract: Grasslands cover a large area of terrestrial China. However, the consensus has not been reached so far with regard to their distribution, biomass, productivity and other properties of the extensive ecosystem. A comprehensive assessment on the grassland ecosystem is needed not only for its integrated development and sustainable utilization, but also for understanding its ecological role in future climate change. We surveyed a large body of the literature accumulated during last few decades, combining with model estimation to clarify the grassland distribution, biomass and productivity. The grassland area varied largely among different studies with the range from 1.67×106–4.31×106 km2. We considered that an area from 2.80×106 km2 to 3.93×106 km2 would be reasonable depending on the vegetation map. The averaged biomass of China’s grasslands varied greatly among previous study, ranging from 79–123 g m-2. Using remote sensing dataset of vegetation index（NOAA/AVHRR-NDVI） and corresponding climate data, our re-estimation indicated that the mean above-ground biomass of natural grassland from 1982–2011 is about 178 g m-2, with an increasing rate of 0.4 g m-2 a-1. The net primary productivity reported so far, ranging from 89–320 g Cm-2 a-1 with an average of 176 g Cm-2 a-1, showed also an increasing trend. The potential primary productivity based on the climate model was much higher and reached about 348 g Cm-2 a-1. Comparing with nature grasslands, the sown pasture area is much smaller and is only about 2.09×107 hm2, but its productivity was 2.7–12.1 times higher than that of natural grasslands. Concerning with the livestock grazing in China’s grassland, we found that the carrying capacity of natural grassland in China is very low, with the average overgrazing rate estimated to be about 20%. Precipitation is the most important factors affecting grassland biodiversity, biomass and productivity and their distribution pattern in China. Because of the extensive area and frangible environments, it is critical to further explore the effects of climate change and human activities such as livestock grazing on the vast grasslands in the East Asia.
Pages: 139-154
Year: 2016 Issue: 2
Journal: Chinese Science Bulletin
Keyword: grassland area; distribution; bio-diversity; biomass; productivity; carrying capacity;
Abstract: Grasslands cover a large area of terrestrial China. However, the consensus has not been reached so far with regard to their distribution, biomass, productivity and other properties of the extensive ecosystem. A comprehensive assessment on the grassland ecosystem is needed not only for its integrated development and sustainable utilization, but also for understanding its ecological role in future climate change. We surveyed a large body of the literature accumulated during last few decades, combining with model estimation to clarify the grassland distribution, biomass and productivity. The grassland area varied largely among different studies with the range from 1.67×106–4.31×106 km2. We considered that an area from 2.80×106 km2 to 3.93×106 km2 would be reasonable depending on the vegetation map. The averaged biomass of China’s grasslands varied greatly among previous study, ranging from 79–123 g m-2. Using remote sensing dataset of vegetation index（NOAA/AVHRR-NDVI） and corresponding climate data, our re-estimation indicated that the mean above-ground biomass of natural grassland from 1982–2011 is about 178 g m-2, with an increasing rate of 0.4 g m-2 a-1. The net primary productivity reported so far, ranging from 89–320 g Cm-2 a-1 with an average of 176 g Cm-2 a-1, showed also an increasing trend. The potential primary productivity based on the climate model was much higher and reached about 348 g Cm-2 a-1. Comparing with nature grasslands, the sown pasture area is much smaller and is only about 2.09×107 hm2, but its productivity was 2.7–12.1 times higher than that of natural grasslands. Concerning with the livestock grazing in China’s grassland, we found that the carrying capacity of natural grassland in China is very low, with the average overgrazing rate estimated to be about 20%. Precipitation is the most important factors affecting grassland biodiversity, biomass and productivity and their distribution pattern in China. Because of the extensive area and frangible environments, it is critical to further explore the effects of climate change and human activities such as livestock grazing on the vast grasslands in the East Asia.
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