Effects of the distribution of biological soil crust on the hydrodynamic characteristics of surface runoff

doi:10.13287/j.1001-9332.202103.017

Abstract

Abstract: The distribution pattern of biological soil crusts (biocrusts) is one of the main factors affecting runoff and sediment yield. The relationship between runoff and sediment yield and biocrusts’ distribution pattern is not clear, which hinders understanding the mechanism underlying the effects of biocrusts on runoff and sediment from slopes. To fill the knowledge gap, we investigated the relationship between the landscape indices of three biocrusts’ distribution patterns, i.e. zonation, chessboard and random, and the hydraulic parameters, using of simulated rainfall experiments and landscape ecology methods. The results showed that biocrust significantly affected the erosion force of slopes and that its distribution pattern could affect slope erosion dynamics. Compared to bare soil, the presence of biocrusts significantly reduced the runoff velocity (54.6%) and Froude number (67.0%), increased the runoff depth (86.2%) and Darcy-Weisbach resistance coefficient (10.68 times), but did not affect the Reynolds number and runoff power. Expect for the runoff depth, there were significant differences in the hydraulic parameters of the three biocrusts’ distribution patterns, with the random pattern having the strongest impacts on the dynamics of slope erosion. Based on factor analysis and cluster analysis, five indices of percentage of patch to landscape area, patch density, landscape shape index, patch cohesion and splitting could be used as the indicators for the distribution characteristics of biocrust patches. The patch cohesion and splitting of biocrust patches were the main distribution pattern indices of the hydrodynamics of surface runoff. As the patches patch cohesion decreased, the splitting increased, which caused the surface runoff velocity increase, the resistance decrease, and the slope erosion became more severe.

Key words: biological soil crust, surface runoff, landscape index, degree of fragmentation, connectivity

JI Jing-yi, ZHAO Yun-ge, YANG Kai, ZHANG Wan-tao, GAO Li-qian, MING Jiao, WANG Shan-shan. Effects of the distribution of biological soil crust on the hydrodynamic characteristics of surface runoff[J]. Chinese Journal of Applied Ecology, 2021, 32(3): 1015-1022.

References 25

[1]	Horton RE, Htrata T. Erosional development of streams and their drainage basins, hydrophysical approach to quantitative morphology. Journal of the Japanese Forestry Society, 1955, 37: 257-262
[2]	Morgan RPC. Soil erosion and conservation. Earth Science Reviews, 1995, 24: 68-69
[3]	Foster GR, Meyer LD, Onstad CA. An erosion equation derived from basic erosion principles. Transactions of the American Society of Agricultural Engineering, 1977, 20: 678-682
[4]	张科利. 黄土坡面发育的细沟水动力学特征的研究. 泥沙研究, 1999(1): 3-5 [Zhang K-L. Hydrodynamic characteristics of rill flow on loess slopes. Journal of Sediment Research, 1999(1): 3-5]
[5]	姚文艺. 坡面流阻力规律试验研究. 泥沙研究, 1996(1): 74-82 [Yao W-Y. Experiment study on hydraulic resistance laws of overland sheet flow. Journal of Sediment Research, 1996(1): 74-82]
[6]	胡世雄, 靳长兴. 坡面土壤侵蚀临界坡度问题的理论与实验研究. 地理学报, 1999, 54(4): 3-5 [Hu S-X, Jin C-X. Theoretical analysis and experimental study on the critical slope of erosion. Acta Geographica Sinica, 1999, 54(4): 3-5]
[7]	张科利, 唐克丽. 黄土坡面细沟侵蚀能力的水动力学试验研究. 土壤学报, 2000, 37(1): 9-15 [Zhang K-L, Tang K-L. A study on hydraulic characteristics of flow for prediction of rill detachment capacity on loess slope. Acta Pedologica Sinica, 2000, 37(1): 9-15]
[8]	张培培, 赵允格, 王媛, 等. 黄土高原丘陵区生物结皮土壤的斥水性. 应用生态学报, 2014, 25(3): 657-663 [Zhang P-P, Zhao Y-G, Wang Y, et al. Impact of biological soil crusts on soil water repellence in the hilly Loess Plateau region, China. Chinese Journal of Applied Ecology, 2014, 25(3): 657-663]
[9]	赵允格, 许明祥, 王全九, 等. 黄土丘陵区退耕地生物结皮对土壤理化性状的影响. 自然资源学报, 2006, 21(3): 441-448 [Zhao Y-G, Xu M-X, Wang Q-J, et al. Impact of biological soil crust on soil physical and chemical properties of rehabilitated grassland in hilly Loess Plateau, China. Journal of Natural Resources, 2006, 21(3): 441-448]
[10]	王媛, 赵允格, 姚春竹, 等. 黄土丘陵区生物土壤结皮表面糙度特征及影响因素. 应用生态学报, 2014, 25(3): 647-656 [Wang Y, Zhao Y-G, Yao C-Z, et al. Surface roughness characteristics of biological soil crusts and its influencing factors in the hilly Loess Pla-teau region, China. Chinese Journal of Applied Ecology, 2014, 25(3): 647-656]
[11]	杨凯, 赵允格, 马昕昕. 黄土丘陵区生物土壤结皮层水稳性. 应用生态学报, 2012, 23(1): 173-177 [Yang K, Zhao Y-G, Ma X-X. Water stability of biolo-gical soil crusts in hilly regions of Loess Plateau, Northwest China. Chinese Journal of Applied Ecology, 2012, 23(1): 173-177]
[12]	李林, 赵允格, 王一贺, 等. 不同类型生物结皮对坡面产流特征的影响. 自然资源学报, 2015, 30(6): 1013-1023 [Li L, Zhao Y-G, Wang Y-H, et al. Impact of different types of biological soil crusts on slope runoff generation. Journal of Natural Resources, 2015, 30(6): 1013-1023]
[13]	秦宁强, 赵允格. 生物土壤结皮对雨滴动能的响应及削减作用. 应用生态学报, 2011, 22(9): 2259-2264 [Qin N-Q, Zhao Y-G. Responses of biological soil crust to and its relief effect on raindrop kinetic energy. Chinese Journal of Applied Ecology, 2011, 22(9): 2259-2264]
[14]	冉茂勇, 赵允格, 刘玉兰. 黄土丘陵区不同盖度生物结皮土壤抗冲性研究. 中国水土保持, 2011(12): 43-45 [Ran M-Y, Zhao Y-G, Liu Y-L. Soil anti-scour ability of biological soil crust with different coverage in Loess Hilly Region. Soil and Water Conservation in China, 2011(12): 43-45]
[15]	吉静怡, 赵允格, 杨凯, 等. 黄土丘陵区生物结皮坡面产流产沙与其分布格局的关联. 生态学报, 2021, 41(4): 1-10 [Ji J-Y, Zhao Y-G, Yang K, et al. Correlation between runoff and sediment yield from biological soil crustal slope and its distribution patterns in the Hilly Loess Plateau Region. Acta Ecologica Sinica, 2021, 41(4): 1-10]
[16]	张元明, 陈晋, 王雪芹, 等. 古尔班通古特沙漠生物结皮的分布特征. 地理学报, 2005, 60(1): 53-60 [Zhang Y-M, Chen J, Wang X-Q, et al. The distribution patterns of biological soil crust in Gurbantunggut Desert. Acta Geographica Sinica, 2005, 60(1): 53-60]
[17]	卜崇峰, 张朋, 叶菁, 等. 陕北水蚀风蚀交错区小流域苔藓结皮的空间特征及其影响因子. 自然资源学报, 2014, 29(3): 490-499 [Bu C-F, Zhang P, Ye J, et al. Spatial characteristics of moss-dominated soil crust and its impact factors in small watershed in Wind-Water Erosion Crisscross Region, Northern Shaanxi Province, China. Journal of Natural Resources, 2014, 29(3): 490-499]
[18]	邬建国. 景观生态学-格局、过程、尺度与等级(第2版). 北京: 高等教育出版社, 2007 [Wu J-G. Landscape Ecology: Pattern, Process, Scale and Hierarchy (2nd edition). Beijing: Higher Education Press, 2007]
[19]	刘宇, 吕一河, 傅伯杰. 景观格局-土壤侵蚀研究中景观指数的意义解释及局限性. 生态学报, 2011, 31(1): 267-275 [Liu Y, Lyu Y-H, Fu B-J. Implication and limitation of landscape metrics in delineating relationship between landscape pattern and soil erosion. Acta Ecologica Sinica, 2011, 31(1): 267-275]
[20]	郑粉莉, 高学田. 坡面土壤侵蚀过程研究进展. 地理科学, 2003, 23(2): 230-235 [Zheng F-L, Gao X-T. Research progresses in hillslope soil erosion processes. Scientia Geographica Sinica, 2003, 23(2): 230-235]
[21]	高丽倩. 黄土高原生物结皮土壤抗水蚀机理研究. 博士论文. 北京: 中国科学院大学, 2017 [Gao L-Q. Effects and the Mechanism of Biological Soil Crusts on Water Erosion Prevention on the Loess Plateau. PhD Thesis. Beijing: The University of Chinese Academy of Sciences, 2017]
[22]	赵明, 杨晓楠, 陈攀宇, 等. 灌木斑块格局对产流及产沙过程的影响. 应用生态学报, 2020, 31(3): 735-743 [Zhao M, Yang X-N, Chen P-Y, et al. Effect of shrub patch pattern on runoff and sediment yield. Chinese Journal of Applied Ecology, 2020, 31(3): 735-743]
[23]	杨凯, 赵军, 赵允格, 等. 生物结皮坡面不同降雨历时的产流特征. 农业工程学报, 2019, 35(23): 135-141 [Yang K, Zhao J, Zhao Y-G, et al. Characteristics of runoff on biological soil crust slope in different rainfall durations. Transactions of the Chinese Society of Agricultural Engineering, 2019, 35(23): 135-141]
[24]	张冠华, 刘国彬, 易亮. 植被格局对坡面流阻力影响的试验研究. 水土保持学报, 2014, 28(4): 55-59 [Zhang G-H, Liu G-B, Yi L. Effects of vegetation patterns on overland flow resistance. Journal of Soil and Water Conservation, 2014, 28(4): 55-59]
[25]	马勇勇, 李占斌, 任宗萍, 等. 草带布设位置对坡沟系统水文连通性的影响. 农业工程学报, 2018, 34(8): 170-176 [Ma Y-Y, Li Z-B, Ren Z-P, et al. Effect of different positions of grass strips on hydrological connectivity in slope-gully system. Transactions of the Chinese Society of Agricultural Engineering, 2018, 34(8): 170-176]