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在野外调查采样的基础上,采用单滴雨滴法研究了黄土高原水蚀风蚀交错区不同类型生物结皮对雨滴动能的响应及削减作用.结果表明:生物结皮对雨滴动能的响应与其生物组成密切相关,击穿1cm厚浅色藻结皮和80%盖度藓结皮的累积雨滴动能分别为0.99J和75.56J;相同组成的生物结皮对雨滴动能的响应与其生物量有关,生物量越大,击穿生物结皮所需累积雨滴动能越大;当藻结皮叶绿素a含量(表征藻结皮生物量)从3.32μg·g-1增至3.73μg·g-1时,对应的雨滴动能则由0.99J增至2.17J;当藓结皮的生物量从2.03g·dm-2升至4.73g·dm-2时,其对应的雨滴动能由6.08J增至75.56J;生物结皮演替过程中对雨滴动能的响应呈“S”形曲线变化.不同生物量的藻结皮对雨滴动能耐受能力的差异不显著;随单位面积苔藓生物量的增加,藓结皮对雨滴动能的耐受能力显著增加.藓结皮对雨滴动能的耐受能力在生物量2.03～4.73g·dm-2之间呈线性增加;当藓结皮平均生物量达3.70g·dm-2时,可以抗击62.03J的雨滴动能.生物结皮对雨滴动能有显著的削弱作用,且这种削弱作用随着生物量的增加而增加.
Based on the field sampling, the single-drop raindrop method was used to study the response of different types of bio-crusts to the kinetic energy of raindrops in the ecotone between water erosion and erosion in the Loess Plateau.The results showed that the response of the bio-crust to the kinetic energy of raindrops was closely related to their bioactivities The cumulative raindrop kinetic energy of penetrating 1 cm thick light color algal crust and 80% covered moss crust were 0.99J and 75.56J, respectively. The response of the same composition of biological crust to raindrop kinetic energy correlated with its biomass, The larger the kinetic energy of accumulated raindrops required to penetrate the biological crusts, the more raindrops were observed when chlorophyll a content in the crust (representing the biomass of algal crusts) increased from 3.32 μg · g-1 to 3.73 μg · g-1 The kinetic energy increased from 0.99J to 2.17J. When the biomass of moss crust increased from 2.03g · dm-2 to 4.73g · dm-2, the kinetic energy of raindrops increased from 6.08J to 75.56J. The response to the kinetic energy of raindrops showed “S” curve during the succession process.The difference in kinetic energy of raindrops between different biomass algal crusts was insignificant.With the increase of moss biomass per unit area, Raindrop kinetic energy tolerance increased significantly. Moss crust on the kinetic energy tolerance of raindrops in biological 2.03 ~ 4.73g · dm-2, the kinetic energy of raindrop at 62.03J could be counteracted when the average biomass of moss crust reached 3.70g · dm-2.The bio-crust significantly weakened the kinetic energy of raindrops, And this weakened effect increases with the increase of biomass.