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Grassland degradation

About: Grassland degradation is a research topic. Over the lifetime, 915 publications have been published within this topic receiving 14146 citations.


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Journal ArticleDOI
TL;DR: A comprehensive satellite-based evaluation of lake shrinkage across the Mongolian Plateau finds a greater decreasing rate of the number of lakes in Inner Mongolia than in Mongolia between the late 1980s and 2010, due mainly to an unsustainable mining boom and agricultural irrigation in the former.
Abstract: Lakes are widely distributed on the Mongolian Plateau and, as critical water sources, have sustained Mongolian pastures for hundreds of years. However, the plateau has experienced significant lake shrinkage and grassland degradation during the past several decades. To quantify the changes in all of the lakes on the plateau and the associated driving factors, we performed a satellite-based survey using multitemporal Landsat images from the 1970s to 2000s, combined with ground-based censuses. Our results document a rapid loss of lakes on the plateau in the past decades: the number of lakes with a water surface area >1 km2 decreased from 785 in the late 1980s to 577 in 2010, with a greater rate of decrease (34.0%) in Inner Mongolia of China than in Mongolia (17.6%). This decrease has been particularly pronounced since the late 1990s in Inner Mongolia and the number of lakes >10 km2 has declined by 30.0%. The statistical analyses suggested that in Mongolia precipitation was the dominant driver for the lake changes, and in Inner Mongolia coal mining was most important in its grassland area and irrigation was the leading factor in its cultivated area. The deterioration of lakes is expected to continue in the following decades not only because of changing climate but also increasing exploitation of underground mineral and groundwater resources on the plateau. To protect grasslands and the indigenous nomads, effective action is urgently required to save these valuable lakes from further deterioration.

358 citations

Journal ArticleDOI
TL;DR: A study of carbon (C) storage in the 0-0.75-m profile of soils subtending various types of grasslands on the Qinghai-Tibetan Plateau showed that the organic carbon content of such lands in the region reaches 33.52 Pg of C, which represents 23.44% of China's total organic soil-stored carbon and 2.5% of the global pool of soil carbon.

339 citations

Journal ArticleDOI
TL;DR: 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 soil organic carbon (SOC) stocks over the whole profile and their changes in China in last 20 years.
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.

332 citations

Journal ArticleDOI
TL;DR: In this article, the authors present a review of the present situation of grassland desertification in China, and discuss mechanisms of grass land degradation, including overgrazing, cropland misuse and unregulated collection of fuel and medical plants.
Abstract: Grasslands in China cover nearly 4 million km 2 , more than 40% of its total land area. Grasslands play an important role in livestock farming and environmental conservation. In spite of numerous efforts that have been undertaken to arrest land desertification in China, grassland degradation is advancing over wide areas through overgrazing, cropland misuse and unregulated collection of fuel and medical plants. This review presents specific examination of the present situation of grassland desertification in China, and discusses mechanisms of grassland degradation. Assessments of desertification since the 1980s are introduced, and its expanse and extent are discussed. Many scientists admit that both are causes, but two contradicting arguments surround the main cause of desertification, with one citing natural origins such as climate change, and the other pointing to anthropogenic factors such as overgrazing. Trials for clarifying mechanisms of grassland degradation are attempted from the perspective of water and energy dynamics. In addition, causes and measures of moving sand dunes and sandstorms are also discussed. For elucidation of the mechanisms of grassland degradation, the grassland ecosystem functions must be considered. Among the proposals, a mathematical approach and measurement of spectral reflectance are some new methods that are effective for assessing those functions. Measurements of soil respiration under altered grazing intensities are also useful to examine prospects in the event of global climate change. Several technologies for grassland diagnosis have been developed to arrest grassland deterioration. Indicator plant species have been determined according to grassland types. Relations of grazing pressure and species distribution have been quantified. Several measures for restoration of degraded grasslands are proposed as the next step of development in this field, including agro-ecological measures. A promising tool for grassland monitoring is the use of remote sensing in conjunction with geographic information systems. Accurate and real-time monitoring and management of grasslands have become increasingly feasible through sensor improvement in satellite and geographic information systems generalization in recent years.

330 citations

18 Dec 2015
TL;DR: In this article, the authors performed a satellite-based survey using multitemporal Landsat images from the 1970s to 2000s, combined with ground-based censuses to quantify the changes in all of the lakes on the plateau and the associated driving factors, and found that the number of lakes with a water surface area > 1 km2 decreased from 785 in the late 1980s to 577 in 2010.
Abstract: Lakes are widely distributed on the Mongolian Plateau and, as critical water sources, have sustained Mongolian pastures for hundreds of years. However, the plateau has experienced significant lake shrinkage and grassland degradation during the past several decades. To quantify the changes in all of the lakes on the plateau and the associated driving factors, we performed a satellite-based survey using multitemporal Landsat images from the 1970s to 2000s, combined with ground-based censuses. Our results document a rapid loss of lakes on the plateau in the past decades: the number of lakes with a water surface area >1 km2 decreased from 785 in the late 1980s to 577 in 2010, with a greater rate of decrease (34.0%) in Inner Mongolia of China than in Mongolia (17.6%). This decrease has been particularly pronounced since the late 1990s in Inner Mongolia and the number of lakes >10 km2 has declined by 30.0%. The statistical analyses suggested that in Mongolia precipitation was the dominant driver for the lake changes, and in Inner Mongolia coal mining was most important in its grassland area and irrigation was the leading factor in its cultivated area. The deterioration of lakes is expected to continue in the following decades not only because of changing climate but also increasing exploitation of underground mineral and groundwater resources on the plateau. To protect grasslands and the indigenous nomads, effective action is urgently required to save these valuable lakes from further deterioration.

312 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202341
2022114
202168
202071
201963
201844