The effects of varied soil properties induced by natural grassland succession on the process of soil detachment

Vegetation restoration is identified as an effective approach to control soil erosion and affects soil detachment and resistance to concentrated flow on the Loess Plateau. However, the effects of vegetation restoration at gully heads in loess‐tableland remains unclear. This study was performed to investigate the effects of nine vegetation restoration types at gully heads on soil detachment rate (Dr) and soil resistance to concentrated flow (i.e. soil erodibility, Kr and critical shear stress, τc). Undisturbed soil samples were collected from nine vegetation‐restored lands and one slope cropland (as the control) and were subjected to a hydraulic flume to obtain Dr values of gully heads under six inflow discharges (0.5–3.5 L s‐1). The results showed that the Dr values of nine revegetated gully heads were 77.11% to 95.81% less than that of slope cropland, and the grassland dominated by Cleistogenes caespitosa and the shrubland dominated by Hippophae rhamnoides had a relatively greater decrease in Dr than those of other seven restoration types. The Dr value of nine revegetated gully heads could be better simulated by stream power than by flow velocity and shear stress and was also significantly affected by soil disintegration rate (positively), soil bulk density, saturated hydraulic conductivity, organic matter content, and water‐stable aggregate stability (negatively). Additionally, roots with diameters of 0 to 0.5 mm showed a greater effect on Dr than those with larger diameters. Compared to cropland, the nine restored types reduced Kr by 76.26% to 94.26% and improved τc by 1.51 to 4.68 times. The decrease in Kr and the increase in τc were significantly affected by organic matter content, water‐stable aggregate, mean weight diameter of aggregate and root mass density. The combination of grass species (Cleistogenes caespitosa) and shrub (Hippophae rhamnoides) could be considered the best vegetation restoration types for improving soil resistance of gully heads to concentrated flow. © 2019 John Wiley & Sons, Ltd.

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Impacts of different vegetation restoration options on gully head soil resistance and soil erosion in loess tablelands

Guo

Wang

et al. 2020

Soil erodibility as impacted by vegetation restoration strategies on the Loess Plateau of China

Wang

Zhang

et al. 2018

Self Cite

Near soil surface characteristics change significantly with vegetation restoration, and thus, restoration strategies likely affect soil erodibility. However, few studies have been conducted to quantify the effects of vegetation restoration strategies on soil erodibility in regions experiencing rapid vegetation restoration. This study was conducted to evaluate the effects of vegetation restoration strategies on soil erodibility, reflected by soil cohesion (Coh), penetration resistance (PR), saturated conductivity (Ks), number of drop impacts (NDI), mean weight diameter of soil aggregates (MWD), and soil erodibility K factor on the Loess Plateau. One slope farmland and five 25‐year‐restored lands covered by old world bluestem, korshinsk peashrub, shrub sophora, sea‐buckthorn, and black locust were selected as test sites. The old world bluestem was restored via natural succession, while the other four lands were restored by artificial planting. A comprehensive soil erodibility index (CSEI) was produced by a weighted summation method to quantify the effects of vegetation restoration strategies on soil erodibility completely. The results showed that Coh, Ks, NDI, and MWD of the five restored lands were greater than those of the slope farmland. However, the PR and K of the five restored lands were less than those of the slope farmland. CSEI varied greatly under different restoration strategies, from 1 to 0.214. Compared with the control, these indices decreased on average by 68.2%, 78.6%, 72.7%, 75.8%, and 62.8% for old world bluestem, korshinsk peashrub, shrub sophora, sea‐buckthorn, and black locust, respectively. The variation in soil erodibility was significantly influenced by biological crust thickness, bulk density, organic matter content, plant litter density, and root mass density. Shrub‐lands via artificial planting, especially korshinsk peashrub, were considered the most effective restoration strategies to reduce soil erodibility on the Loess Plateau. The results are helpful for selecting vegetation restoration strategies and asking their benefits in controlling soil erosion. © 2018 John Wiley & Sons, Ltd.

Soil erosion resistance of gully system under different plant communities on the Loess Plateau of China

Zeng,

Zhang,

et al. 2024

Gully erosion, considered as a type of intensive erosion, is the dominant source of sediment at small watershed scales in certain environments. Variation of vegetation may result in the changes in near soil surface characteristics, which likely further affect the resistance of gully systems to erosion. However, the potential effects of near soil surface characteristics of plant communities on resistance to erosion are still unclear in gully systems. This study was performed to investigate the variations in resistance of gully systems to erosion under different plant communities and to identify the dominant influencing factors leading to these variations on the Loess Plateau. Five typical plant communities (two grasses, two shrubs and one forest) that distributed on different gully systems were selected. Six hundred undisturbed soil samples collected from different sites of gully systems were subjected to detach by overland flow under six different shear stresses (6.66 to 15.02 Pa). The results showed that the mean soil detachment capacity of gully systems covered by grass and shrub communities was 0.15 and 0.37 times to that of gully system covered by forest. Compared to forest gully systems, rill erodibility reduced by 29.8% to 85.6% for the other four plant communities. The relative rill erodibility of different vegetation communities generally increased from grass to shrub and forest communities. The critical shear stress of forest gully system was 58.7% and 63.8% of gully systems covered by grass (6.22 Pa) and shrub (5.73 Pa) communities. Bulk density, soil cohesion, water stable aggregate, root mass density, and the thickness of biological soil crust were the dominant factors affecting the resistance of gully systems to soil erosion. Rill erodibility decreased logarithmically with increasing soil cohesion, water stable aggregate and root mass density. Critical shear stress increased with the increase of soil cohesion and root mass density as a power function, and linearly with the increase of water stable aggregate. These results show how vegetation can mitigate against the erosion induced by concentrated flow in relatively stable gully systems.