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通过野外定位观测试验,探讨了黄土区不同植被类型下生物结皮的土壤水分入渗和水土保持效应。分析结果表明:①单纯BSC降低入渗,减幅达8.3%,但入渗效应并非呈单一的增加或减少的表现形式。生物结皮与植被(长芒草和柠条)组合时,入渗增加作用进一步提高,但生物结皮的贡献率明显低于植被,长芒草、柠条下生物结皮的增渗幅度分别为8.5%,0.2%。②雨季初期BSC减少地表径流(减幅约50%),雨季后期径流反而增加。生物结皮同覆盖度较高的长芒草组合时,减流贡献很小,径流调控率<15%,而与覆盖度较低的柠条组合时,减流作用明显,径流调控率达22.7%～43.0%。③BSC控蚀作用明显,全年减蚀量可达93.8%。植被类型对生物结皮的减蚀作用影响很大,长芒草植被下减蚀贡献率仅为3.1%,而柠条植被下减蚀贡献率高达37.6%。
Through the field observation test, the effects of soil water infiltration and soil and water conservation on the biological crust under different vegetation types in the loess area were discussed. The results show that: (1) BSC reduces infiltration only by 8.3%, but the infiltration effect is not a single manifestation of increase or decrease. When the combination of biological crusts and vegetation (such as Chang Miscanthus and Caragana korshinskii), the infiltration increased further, but the contribution rate of biological crusts was significantly lower than that of vegetation. The increase rates of biological crusts were respectively 8.5 %, 0.2%. ② In the early rainy season, BSC reduced surface runoff (about 50% of the decrease), and runoff increased later in the rainy season. When the biological crusts were combined with the mangosteen with higher coverage, the contribution of flow reduction was very small, and the regulation of runoff was less than 15%. When combined with the karst grass with lower coverage, the flow reduction effect was obvious and the regulation rate of runoff was 22.7% ~ 43.0%. ③ BSC corrosion control significantly, the annual reduction of up to 93.8%. Vegetation types have a great impact on the bio-crust erosion reduction. The contribution of erosion reduction to the vegetation is only 3.1%, while the contribution of erosion reduction to the soil is up to 37.6%.