干旱荒漠区斑块状植被空间格局及其防沙效应研究进展

斑块状植被相对稳定的空间格局是其适应环境的结果,也是干旱区植被存在的主要形式.干旱荒漠区植被对土壤风蚀的防护功能不仅与盖度、高度有关,而且与植被空间格局有关.以往的研究多侧重于植被盖度和高度对防护功能的影响,而对植被格局影响防沙效应的研究相对薄弱.干旱区斑块状格局的植被能否防沙、防沙效应如何一直是防沙治沙工程研究中的焦点问题.综述了干旱区斑块状植被空间格局特征、形成演化及防风固沙效应等方面的研究进展,提出未来应借助3S技术手段和模型模拟方法,加强对斑块状植被空间格局与风蚀风积过程的互馈关系、斑块动态的驱动因素和斑块状植被格局防沙功能的尺度效应研究.

Reviews on spatial pattern and sand-binding effect of patch vegetation in arid desert area

The relatively stable spatial pattern of patch vegetation attributes to its adaptation to the arid desert environment, as well as the vegetation appears the main form in arid areas. In the arid desert area, the protective functions of vegetation on soil wind erosion not only relate with vegetation coverage and height, but also relate with the spatial pattern of vegetation. In the previous study put emphasis on the effect of vegetation coverage and height on protective functions of land surface, but the research that the impacts of vegetation pattern on sand break effect is relatively weak. It is always a major issue in the studies of sandy desertification combating works whether and how this kind of vegetation spatial pattern is effective in preventing sand. The results of the present study indicate that patch vegetation in arid area plays an important role in fixed sand dune, resisting hazards of wind-blown sand and protecting the oasis. This article gives review of the research of patch vegetation, including its evolution mechanism and evolution process, spatial pattern characteristics of population, impact factors of dynamic changes, differentiation between patches and patch gaps, spatial heterogeneity and effect of sand-fixation. Besides, the weakness in the present research is also pointed out. Moreover, it is strongly suggested that the 3S technology and simulation method should be used in the future study, especially in the research of impact factors in patch vegetation dynamics, feedback relationship between spatial pattern of patch vegetation and process of wind erosion and deposition, and scale effect of patch vegetation on sand-binding. These research results provide the theoretical basis and practice instruction for plant species choice and spatial pattern allocation in large scale ecological vegetation construction of arid desert area.