JOURNAL OF NATURAL RESOURCES ›› 2015, Vol. 30 ›› Issue (6): 1013-1023.doi: 10.11849/zrzyxb.2015.06.012

• Resource Evaluation • Previous Articles     Next Articles

Impact of Different Types of Biological Soil Crusts on Slope Runoff Generation

LI Lin1,2, ZHAO Yun-ge2, WANG Yi-he2,3, WANG Yuan1,2   

  1. 1. College of Resources and Environment, Northwest A & F University, Yangling 712100, China;
    2. State Key Laboratory of Soil Erosion and Dry-land Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, China;
    3. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2014-04-24 Revised:2014-10-21 Online:2015-06-20 Published:2015-06-20

Abstract:

Biological soil crusts (biocrusts) are non- ignorable influence factors of soil and water loss in the Loess Plateau region of China, however the impact of biocrusts on slope runoff generating is poorly understood so far. In Liudaogou small catchment that locates in Shenmu County, north of Shaanxi Province, the impact of four types of biocrusts and bare soil (no biocrusts) on runoff generating were studied in the runoff plots through simulated overland flow experiment. The four types of biocrusts were light cyanobacterial crust, dark cyanobacterial crust, cyanobacterial with moss crust (mixed crust hereafter) and moss dominated crust, which represent four different succession stages of biocrusts in the region. The results showed that: 1) compared with bare land, both light, dark cyanobacterial crusts and mixed crusts significantly reduced the time of runoff initiation by 89.0%, 96.2% and 96.0%; While the moss dominated crust markedly increased the time of runoff initiation. 2) The duration of runoff recession on light cyanobacterial crust and mixed crust were respectively 2.28 and 2.13 times higher than that on bare land; while that on dark cyanobacterial crust had no significant difference with that on bare land plot. 3) The runoff velocity was reduced by 29.1% by the dark cyanobacterial crust and 67.3% by the moss dominated crust compared with that on bare land; The runoff velocity on moss dominated crust was markedly slower than that on the other biocrust land. The runoff depth in biocrust plots did not show significant difference with that in bare land plot; The runoff depth on light cyanobacterial crust was significantly deeper than that on dark cyanobacterial crust. 4) The process and the amount of runoff in plots with different types of biocrusts showed obvious differences with that in bare land plots; The runoff coefficient in light cyanobacterial crust plot was significantly higher than that in bare land plots, while the runoff coefficient in dark cyanobacterial crust plots and mixed crust plots had no significant difference with thatin bare land plot. The runoff coefficient in light cyanobacterial crust plot was 2.44 times higher than that in dark cyanobacterial crust plots; No runoff generated on moss dominated crust during the runoff period. The results suggested that biocrusts are important influence factors on runoff generation, and the extend of influence was related to the succession stages and the composition of the biocrusts.

Key words: biological soil crust, runoff characteristics, runoff velocity, runoff depth, runoff coefficient

CLC Number: 

  • S157.2