The constraint effect of grassland vegetation on soil wind erosion in Xilin Gol of China

Abstract

As an important part of the natural ecosystem, grassland has great significance to worldwide sustainability. The Xilin Gol grassland is the closest natural grassland to Beijing, the wind and sand conditions there can have a direct impact on Beijing's ecological environment. This study estimated the net primary productivity (NPP) and soil erosion by wind (SL) from 2001 to 2014 in the Xilin Gol League, and 10 equally spaced constraint lines from 10 % to 99.99 % quantile of NPP-SL scatter cloud were extracted for each year. We also analyzed the eigenvalues of these constraint lines. The results showed that the soil wind erosion of nearly half area of the Xilin Gol was concentrated in the range of 0–5 kg/m2, where SL was more constrained by non-vegetation factors than NPP from 2001 to 2014. The occurrence of the threshold values for the 60 %-90 % quantile constraint lines in the Xilin Gol grassland was more frequent at NPP levels of 250 gC/m2 and 400 gC/m2. And there was a “constraint bottleneck” between 300 gC/m2 and 400 gC/m2 at the middle steady part of the S-shaped constraint lines, where SL remained relatively stable with the increasing NPP. This study not only broadens the application of the constraint line method in ecology, but also helps to deeply and comprehensively demonstrate the constraint effect of grassland vegetation on soil wind erosion in complex ecosystems, which contributes to regional sustainability.

Keywords

• Constraint line method
• Grassland
• Net primary productivity
• Soil erosion by wind
• Thresholds