砒砂岩区种植沙棘后景观格局变化预测

Prediction of landscape pattern in soft sandstone area after Hippophae rhamnoides planting

沙棘是砒砂岩区沟谷部位常用的一种生态恢复树种。通过运用马尔科夫模型,对种植沙棘后砒砂岩区景观格局变化趋势的分析,预测沙棘等各类景观要素的发展规模,以为科学指导类似沙棘生态工程的建设项目提供相关依据。为探索种植沙棘对景观系统的影响,将沙棘单独分出来作为一种景观类型,与其他常规景观类型一起进行景观格局分析。结果表明:在砒砂岩区,沙棘生态工程建设是对区域景观生态格局变化影响最大的因素;预测确定的砒砂岩区沙棘种植面积的最大比例为10.21%,乔木林地面积比例预测值在10%以下,林地面积过大将会造成土壤干层下移,最终可能导致大片林分死亡现象出现;稀疏植被地的面积稳定比例为32.25%,在干旱少雨的砒砂岩区,较高的稀疏植被比例,是适应当地环境条件的最佳选择。

Hippophae rhamnoides is a kind of pioneer plant in the gully slopes in Soft Sandstone Area （SSA） for eco-economical consideration. By means of Markov model, the ratio trends of each landscape type was determined, which could support the Hippophae rharnnoides project. Separated from shrub type, Hippophae rharnnoides was listed in the landscape types together with the normal types for analysis of landscape pattern. Hippophae rhamnoides project influences the landscape pattern deeply in SSA. The prediction shows that the maximum ratio of Hippophae rhamnoides in the future should be 10.21% , and the forest percentage under 10%, which is very wise to avoid the serious death of forest including Hippophae rhamnoides in the arid climate and soil conditions. The steady ratio for open vegetation is 32.25% , which is a little larger but suitable in the area for matching the eco-environment.