河西走廊防风固沙林结构模式及其影响因素分析

Analysis of the Structural Pattern of the Windbreak and Sand Fixation Forests in Hexi Corridor and Its Influencing Factors

防风固沙林在控制风沙和保障区域生态安全等方面发挥着重要的作用。通过对河西走廊防风固沙林进行调查分析,结果表明:河西走廊防风固沙林的乔木应用比例只有8.18%,灌木树种比例达91.82%,其中梭梭占比60.93%。纯林所占比例达56.82%,其中梭梭纯林的比例达到50.00%;造林密度超过1650株·hm^(-2)林地占调查样地的84.38%,都是株距小行距大的结构均匀林分。灾害性大风和长期干旱影响和限制了防风固沙林分布与人工林建设,早期造林所建防风固沙林密度过大、配置不合理等问题已经显现。

Windbreak and sand fixation forests play an important role in controlling wind-sand and ensuring regional ecological security.Based on the investigation and analysis of the windbreak and sand fixation forests in Hexi Corridor,the results showed as follows:the proportion of trees used in the windbreak and sand fixation forests in Hexi Corridor was only 8.18%,and the proportion of shrub species reached 91.82%,of which Haloxylon ammodendron accounted for 60.93%;the proportion of pure forest in the windbreak and sand fixation forests reached 56.82%,of which the proportion of pure forest Haloxylon ammodendron reached 50.00%;the forest land with the afforestation density more than 1650 plants·m^(-2) accounted for 84.38%of the survey plots,all of which were uniform structure forests with small plant spacing and large row spacing.Severe winds and long-term drought have affected and limited the distribution of the windbreak and sand fixation forests and the construction of the planted forests.The problems,such as excessive density and unreasonable allocation of the windbreak and sand fixation forests of early afforestation have emerged.