Influence of vegetation restoration on soil physical properties in the Loess Plateau, China

Authors: GU, CHAOJUN - Northwest University; MU, XINGMIN - Northwest University; GAO, PENG - Northwest University; ZHAO, GUANGJU - Northwest University; SUN, WENYI - Northwest University; TAN, XUEJIN - Northwest University; Tatarko, John

Submitted to: Journal of Soils and Sediments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/4/2018
Publication Date: 8/2/2018
Citation: Gu, C., Mu, X., Gao, P., Zhao, G., Sun, W., Tan, X., Tatarko, J. 2018. Influence of vegetation restoration on soil physical properties in the Loess Plateau, China. Journal of Soils and Sediments. 19:716-728. https://doi.org/10.1007/s11368-018-2083-3.
DOI: https://doi.org/10.1007/s11368-018-2083-3

Interpretive Summary: In order to control severe soil erosion, extensive vegetation recovery has been implemented on the Loess Plateau of China. Understanding the effects of vegetation restoration on soil properties is essential for assessing the effectiveness and sustainability of environmental recovery in the region. We investigated soil properties of the Yanhe watershed in the hilly-gully region of the Loess Plateau at ten sites with different vegetation types (forest, scrubland, grassland, and farmland) and varying periods of restoration. The results showed that vegetation restoration significantly decreased soil density, while increasing soil porosity, soil clod stability, and water movement in the soil. The soil particle size did not change with vegetation restoration but minor differences in sand, silt and clay components were observed. We found that soil density, porosity, clay content, and clod stability were the principal properties that affected water movement. Analysis also revealed that soil density had the most direct effect on water movement, while clod stability had the least impact. Clay content, porosity, and clod stability were found to have indirect effects on soil density and therefore on water movement. It is reasonable to take soil density and water movement to evaluate vegetation restoration on soil properties because they were correlated with most of other soil properties. Analysis showed that planting shrubs and grassland is better than forest for environment rehabilitation in the study area. Results of this study provide a reference to regional environmental rehabilitation and conservation.

Technical Abstract: In order to control severe soil erosion, extensive vegetation recovery has been implemented on the Loess Plateau, China. Investigating the effects of vegetation restoration on soil properties is essential for assessing the effectiveness and sustainability of eco-environmental rehabilitation in the region. We investigated soil physical properties of the Yanhe watershed in the hilly-gully region of the Loess Plateau at ten sites with different vegetation types (forest, scrubland, grassland, and farmland) and varying restoration periods. The results showed that vegetation restoration significantly decreased bulk density, while increasing capillary porosity, non-capillary porosity, aggregate stability, and saturated hydraulic conductivity (SHC). The soil texture class did not change with vegetation succession but minor differences in sand, silt and clay components were observed. We found that bulk density, non-capillary porosity, clay content, and >0.25 mm aggregate stability were the principal physical parameters that affected SHC. Path coefficient analysis revealed that bulk density had the highest direct effects (-0.48) on SHC, while >0.25 mm aggregate stability had the lowest impact (0.18). The indirect effects of three other parameters on SHC via bulk density are as follows: clay content (-0.70), non-capillary porosity (-0.35), and >0.25 mm aggregate stability (-0.04). It is reasonable to take bulk density and SHC as indicators to evaluate the effect of vegetation restoration on soil physical properties because they were correlated with most of other soil physical properties. Principal component analysis (PCA) indicated that planting shrubs and grassland is better than forest for eco-environment rehabilitation in the study area. Results of this study provide a reference to regional eco-environmental rehabilitation and conservation.