土壤结皮的发育特征及其生态功能研究述评

土壤结皮是干旱半干旱地区普遍存在的地被物，在土壤一水分—植被系统演变过程中发挥重要的生态功能。在阅览大量文献的基础上，回顾了近几十年特别是20世纪80年代以来有关土壤结皮的研究工作成果，总结了有待进一步探讨的问题。主要结论有：1)在自然界，土壤结皮的两大类即生物结皮和物理结皮往往同时存在、相互影响，目前缺乏对两类结皮发育关系的认识；2)土壤结皮的发育具有明显的过程复杂性和空间分异性，其生态作用在不同区域的表现不一，甚至有相反的情况发生；3)部分地区特别是黄土高原地区，相关研究工作起步较晚，迫切需要认识结皮对土壤侵蚀、生态水文等过程的作用。需加快相关研究进程，为精准侵蚀预报模型的构建提供理论依据，为合理保护与利用土壤结皮资源提供科学依据。

Review on Developmental Characteristics and Ecological Functions of Soil Crust

Soil crust, distributing on arid and semi -arid areas, plays important roles in the ecological process of the system of soil-plant-vegetation. Based on large numbers of references, this paper reviewed the fruits and conclusions about soil crust researches in recent several decades, and some problems that need to be studied further also were summarized. The following results were found: 1) Biological soil crust and physical soil crust (two types of soil crust) usually occur together and affect each other in nature; however, few understandings on the relations between them and their multiple effects were known due to separate research for the two types crust artificially; 2) The development of soil crust shows temporal complexity and spatial variation obviously, and also its ecological effects have big differences in different regions or experimental conditions, even some contrary conclusions found; 3) Many researches in such areas as Loess Plateau and Black Soil Region have not been launched untill recent years, and it is necessitous that more studies should be developed to understand favorable or adverse effects of soil crust on soil erosion and its happening conditions and eco -hydrological processes in order to give an academic foundation to physical erosion modeling and effective using of soil crust resources.