JOURNAL OF NATURAL RESOURCES ›› 2014, Vol. 29 ›› Issue (1): 67-79.doi: 10.11849/zrzyxb.2014.01.007

• Resources Evaluation • Previous Articles     Next Articles

The Development Characteristics and Formation Process of Biological Soil Crusts in Wind-Water Erosion Crisscross Region, Northern Shaanxi Province, China

LI Jin-feng1,2, MENG Jie2, YE Jing4, YUAN Fang3, BU Chong-feng*3,4   

  1. 1. Taiyuan University of Technology, Taiyuan 030024, China;
    2. Shanxi Institute of Soil and Water Conservation, Taiyuan 030045, China;
    3. Institute of Soil and Water Conservation, Northwest A & F University, Yangling 712100, China;
    4. Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling 712100, China
  • Received:2012-07-17 Revised:2013-06-24 Online:2014-01-20 Published:2014-01-09
  • Contact: 卜崇峰(1977- ),男,陕西榆林人,博士、硕导,主要从事生物土壤结皮与水土保持工程研究工作。E-mail:buchongfeng@163.com E-mail:buchongfeng@163.com

Abstract: The formation, development and ecological functions of biological soil crusts (BSCs) are characterized by significant temporal and spatial differences, results of many researches from the desert region can not be directly deduced in the Loess Plateau Area. To study the formation process and developmental characteristics of BSCs in the Loess Plateau is not only an important complement to the global cognition of BSCs, but also the precondition to reveal its ecological functions. Selecting typical small watershed (Liudaogou) in the Loess Plateau as a case, this study explores the developmental characteristics of BSCs by positioned dynamic observation, comprehensive investigation and estimation. The results showed as follows: 1) BSCs in Liudaogou watershed experienced a development process of bare farmland-physical crust-biological soil crusts. Physical crust rapidly formed in the first year of farmland abandonment; in the second year, moss-dominated crust developed obviously, and the soil color became apparently darker than before. Moss crust dominated absolutely in the watershed, and its coverage was up to 90% when it developed into a stable stage (>15 years). 2) Years of development had a significant impact on the composition and amounts of species of BSCs. In the initial development stage (<6 years) of BSCs, bryophytes had 5 species under 4 genera belonging to 2 families, of which Aloina rigida (Hedw.) Limpr. and Aloina brevirostris (Hook. & Grev.) Kindb mosses both were the pioneer species. In the stable stage (>15 years) of BSCs, bryophytes had 13 species under 8 genera belonging to 2 families, of which the family Pottiaceae had 6 genera with 8 species, and the dominant species were Didymodon constrictus (Mitt.) Saito, Didymodon nigrescens (Mitt.) Saito and D. rigidulus Headw var ditrichoides (Hedw.) Zand. In addition, in the initial stage (<6 years), 26 families of algae including 50 species under 35 genera were identified in BSCs. 3) Rainy season with warm weather was a critical period of BSCs formation. The thickness of BSCs developed 2 years reached 6.3 mm, which exceeded the stable depth of crust (9.8-11.8 mm) by 50% and the shear strength of BSCs was about 30 kPa. In the initial stage (<6 years), bulk density showed no significant change (1.40-1.43 g ·cm-3), but it reduced to 1.0 to 1.3 g ·cm-3 when development of BSCs went into the stable stage. The formation process of BSCs in this area was similar to that in desert region, but the rate of development is faster and the period to stabilization is shorter. The composition of algae, moss and their dominated species (Leptolyngbya foveolara, Didymodon constrictus (Mitt.) Saito) was apparently different from those in desert region.

Key words: biological soil crusts, wind-water erosion crisscross region, biological composition

CLC Number: 

  • S154.1