Historical grassland desertification changes in the Horqin Sandy Land, Northern China (1985–2013)

Abstract

Since rural reforms in the 1980s, both the state and local governments of China have devoted great efforts to combating desertification through a number of eco-environmental restoration campaigns, resulting in burgeoning contention at all levels of government and sparking public concern. Monitoring and accurately assessing the statuses and trends of grassland desertification are important for developing effective restoration strategies. The Horqin Sandy Land (HSL), a very typical desertified grassland (DG) with better hydrothermal conditions among sandy lands in north China, was recently selected (1985–2013) to assess the spatiotemporal dynamic performances of grassland desertification before and after implementing restoration projects. Landsat images (TM/ETM+/OLI), field investigations and expert review were integrated to form a classification scheme for the HSL. Then, spectral mixture analysis and the decision-tree method were used to extract bare-sand ratios and vegetation cover fraction dynamics. A favourable phenomenon of DG was seen to be reversed in an accelerated pace during 2001–2013, despite challenge from both climatic and anthropogenic factors. However, overexploitation of grassland (especially for farming) and ground water for irrigation has led to remarkable decreases in the ground water level in recent decades, which should be highly concerning regarding the formulation of restoration campaigns in the sandy land.

Monitoring the Spatiotemporal Dynamics of Aeolian Desertification Using Google Earth Engine

“…After manually deleting pixels with abnormal values and incomplete coverage, a total of 2428 pixels were used to determine the UAV-MSR samples, which was then used to verify the accuracy of the LSMM. Compared with selecting samples from the field and visually determining the MSR in previous aeolian desertification studies [40,41], UAVs provide a larger number of more objective and accurate samples with faster acquisition speeds. This effectively compensates for the scale gap between the samples and remote sensing image pixels.…”

Indirect Effects of Grazing on Wind-Dispersed Elm Seeds in Sparse Woodlands of Northern China

“…Horqin Sandy Land is located in a typical agriculture and pasture interlaced zone on the eastern edge of the Mongolian Plateau [35] (Figure 1). Horqin Sandy Land, with an area of 5.23 × 10 4 km 2 , is one of the largest sandy lands in China [36].…”

“…The continuous land degradation of Horqin Sandy Land attracts much attention from researchers and policymakers. A series of national ecological restoration projects, such as the Grain for Green Project and the Beijing and Tianjin Sandstorm Source Treatment Project, was implemented to fight for land degradation and preserve the fragile ecosystems [35].…”

Physiological Responses of Agriophyllum Squarrosum and Setaria Viridis to Drought and Re-watering

“…Northern China's Horqin Sandy Land used to be a famous grassland, but severe deserti cation has occurred since the 1950s 29 . During vegetation restoration to control the deserti cation, the succession that occurs in vegetation communities can be divided into three stages 30 : (1) Pioneer psammophytes such as Agriophyllum.…”

“…The seed yield in Glycine max was positively correlated with SOD activity 27 , and the total antioxidant capacity was strongly signi cantly positively correlated with catalase activity in potato 28 . Northern China's Horqin Sandy Land used to be a famous grassland, but severe deserti cation has occurred since the 1950s 29 . During vegetation restoration to control the deserti cation, the succession that occurs in vegetation communities can be divided into three stages 30 : (1) Pioneer psammophytes such as Agriophyllum.…”