Wu Ji, Yang Guang, Ma Yunxia, Guo Xinyu, Lu Naijing, Chen Zeqing, Wang Zimeng, Wang Ning, Du Hai
College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot, 010018, China.
College of Life Sciences, Yulin University, Yulin, 719000, China.
Sci Rep. 2024 Dec 28;14(1):31149. doi: 10.1038/s41598-024-82469-6.
Vegetation restoration can be effective in containing gully head advance. However, the effect of vegetation restoration type on soil aggregate stability and erosion resistance at the head of the gully is unclear. In this study, five types of vegetation restoration-Pinus tabulaeformis (PT), Prunus sibirica (PS), Caragana korshinskii (CKS), Hippophae rhamnoides (HR), and natural grassland (NG, the dominant species is Leymus chinensis)-in the gully head were studied. Soil aggregate composition and nutrient contents in the 0-20, 20-40, and 40-60 cm soil layers were also determined, and the soil stability parameters were used to evaluate the soil conditions. The soil erodibility (K) was then determined by measuring the granulometric composition and organic matter. The results showed that the particle size of soil aggregates under different vegetation restoration types was mainly < 0.25 mm, and the percentage of aggregate disruption (PAD) was 22.08-76.07%. This further indicated that in Loess hilly and gully regions, water-stable aggregates were more reflective of the stability of soil aggregates in a gully head under vegetation restoration. The > 0.25 mm aggregates (R), geometric mean diameter (GMD), and mean weight diameter (MWD) values of the three soil layers were the highest in PT and the lowest in NG, while the opposite was true for fractal dimension (D) and the percentage of aggregate disruption (PAD). The K ranged from 0.052 to 0.065 t·hm·h·MJ mm·hm. GMD can be used to characterize the anti-erosion ability of soil, and increasing the soil organic carbon, total nitrogen, and clay content can effectively reduce soil erodibility. The comprehensive analysis indicated that the soil aggregates of arbors planted in the gully head had the highest stability and anti-erodibility, followed by shrubs and grasslands, and can be used to evaluate vegetation restoration measures in gully heads.
植被恢复对遏制沟头前进具有显著效果。然而，植被恢复类型对沟头土壤团聚体稳定性和抗侵蚀性的影响尚不明晰。本研究针对沟头的五种植被恢复类型展开研究，分别为油松（PT）、山杏（PS）、柠条锦鸡儿（CKS）、沙棘（HR）以及天然草地（NG，优势种为羊草）。同时测定了0 - 20厘米、20 - 40厘米和40 - 60厘米土层的土壤团聚体组成及养分含量，并运用土壤稳定性参数对土壤状况进行评估。随后通过测定颗粒组成和有机质含量确定土壤可蚀性（K）。结果表明，不同植被恢复类型下土壤团聚体的粒径主要小于0.25毫米，团聚体破坏率（PAD）为22.08% - 76.07%。这进一步表明，在黄土丘陵沟壑区，水稳性团聚体更能反映植被恢复下沟头土壤团聚体的稳定性。三个土层中大于0.25毫米的团聚体（R）、几何平均直径（GMD）和平均重量直径（MWD）值在油松样地最高，在天然草地样地最低，而分形维数（D）和团聚体破坏率（PAD）则相反。K值范围为0.052至0.065吨·公顷·小时·兆焦毫米·公顷。GMD可用于表征土壤的抗侵蚀能力，增加土壤有机碳、全氮和黏粒含量可有效降低土壤可蚀性。综合分析表明，沟头种植乔木的土壤团聚体稳定性和抗侵蚀性最高，其次是灌木和草地，可用于评估沟头植被恢复措施。
