荒漠生物结皮研究中的几个问题

生物结皮在干旱区生态系统中扮演着一个关键的角色，它可以影响干旱区土壤的结构、功能、生产力，包括土壤稳定性、土壤保水力、碳、氮的固定和土壤的肥力等。结合国内外生物结皮的研究，提出生物结皮的影响因子、生物结皮与周围植物的关系、生物结皮形态的变化与分布的异质性等几个问题并进行了讨论。

Recent Progress and Some Existing Problems in the Study on the Desert Microbiotic Crusts

Microbiotic crusts play an important role in the ecosystems in arid and semiarid regions, they affect the structure, functions and productivity of soils, which include the stability, water conserving capability, carbon and nitrogen fixation, fertility, etc. of soils. In recent 20 years, many studies on microbiotic crusts have been carried out at home and abroad, and these studies have the important scientific values and the extensive practical significances for understanding the structures, functions and feedback mechanisms of the ecosystems and landscapes in arid and semiarid areas. In this paper, the domestic and foreign achievements in scientific research on microbiotic crusts are reviewed, and the factors affecting microbiotic crusts, relationship between microbiotic crusts and peripheral vegetation, change and distribution heterogeneity of the conformation of microbiotic crusts are analyzed. It is considered that, although the formation of microbiotic crusts is affected by many biological, environmental and disturbance factors, the microorganisms composing microbiotic crusts are not to passively adapt the environment, in fact, they adapt actively the severe natural conditions in arid and semiarid regions by changing themselves and the peripheral environment.