黄土高原沿黄红枣经济林的生态效益评价

Evaluation on Ecological Benefits of the Jujube Economic Forest along the Yellow River in Loess Plateau

通过野外试验和室内测量分析,研究黄土高原沿黄坡耕地上5种经济林地的生物多样性、植被结构和生态结构的差异,并基于TOPSIS原理对不同经济林地的生态效益进行评价。结果表明,黄土高原沿黄红枣生态经济林从生物多样性的角度看,撂荒5 a红枣经济林的生物多样性最高,撂荒2~3 a红枣经济林和人工森林次之,耕作的成龄红枣经济林和幼龄红枣经济林生物多样性较低;黄土高原沿黄红枣生态经济林从植被结构和生态结构来看,均是人工森林最优,其次是撂荒红枣经济林,耕作的红枣经济林最差;黄土高原沿黄红枣生态经济林从整体的生态效益来看,在良好的管理状态下,坡耕地红枣经济林系统的生态效益有限,难以发挥黄土高原脆弱生态区应有的生态防护功能,撂荒红枣经济林系统的生态效益有所提高,但是距离森林生态系统仍有一定的差距。

This paper studied the difference of biodiversity,vegetation structure and ecological structure among five different economic forests along the Yellow River in the Loess Plateau by field investigation and indoor analysis.TOPSIS principle was used to evaluate the ecological benefits of different economic forests.The results showed that from the angle of biological diversity,the diversity index of jujube forests were the highest in abandoned 5 years,and then abandoned 2-3 years jujube forests and artificial forest,while the lowest value occurred in the normal management jujube economic forests including mature and young trees.The vegetation structure and ecological structure of the five economic forests were all in the same order.The artificial forests were the best,followed by abandoned jujube forests,the normal management jujube economic forests was the worest.Under the normal management,the ecological benefits of the jujube economic forests along the Yellow River were limited.It was difficult to give full play to the ecological protection function in the Loess Hilly region.Although the ecological benefits of the abandoned jujube economic forests were higher than that of the cultivated jujube economic forests,but there were still a certain distance from the ecological benefit provided by the forest ecosystems.