Sand-fixing Function under the Change of Vegetation Coverage in a Wind Erosion Area in Northern China
GONG Guoli, LIU Jiyuan, SHAO Quanqin, ZHAI Jun
2014, 5 (2):
Using meteorological and remote sensing data and changes in vegetation cover during the wind erosion season in northern China, a revised wind erosion equation was applied to evaluate spatiotemporal variation in soil erosion and conservation since the 1990s, and to reveal the effects of the change of vegetation coverage on the wind erosion control service. The results showed that average soil erosion in northern China between 1990 and 2010 was 16.01 billion tons and was decreasing. The most seriously eroded areas were mainly distributed in large desert areas or low cover grasslands. Most wind erosion occurred in spring, accounting for 45.93% of total wind erosion. The average amount of sand fixation service function for northern China between 1990 and 2010 was 20.31 billion tons. Given the influence of wind erosion forces, the service function for sand fixation cannot effectively highlight the role of sand fixation from the ecosystem itself. The retention rate of service function for sand fixation reveals the role of the ecosystem itself. The distribution characteristics of the soil retention rate are similar to vegetation cover, which shows a gradual decrease from southeast to northwest in the study area. Improved spring vegetation cover was observed mainly on the Loess Plateau, Qinghai-Tibet Plateau, in northern Hebei, eastern Inner Mongolia and northeast China after the implementation of ecosystem projects. The soil retention rate in most areas showed a significant positive relationship with grassland vegetation in spring (r > 0.7, p < 0.01). The increments of ecosystem service function for various ecological systems are different. Increments for the grassland ecosystem, forest ecosystem, farmland ecosystem and desert ecosystem are 2.02%, 1.15%, 0.99% and 0.86%, respectively.
Related Articles |