农田防护林林网景观结构定量评价与分析

Quantitative Evaluation and Analysis of Landscape Structure of Farmland Shelterbelt Network

以东北地区的“三北”防护林工程重点建设区为研究对象,选取林网的带斑比、连接度、环度、优势度等作为评价指标,利用高分辨率的ZY-3影像,根据景观生态学原理及地理信息系统技术,对2021年实际林网和合理状态下林网的景观指标值进行定量评估及对比,并分析现有农田防护林景观结构参数的空间分布差异性。结果表明:该区域的防护林数量与面积基本达到优质林网的要求,并且分布较均匀,但是主副林带条数不足,成型状况较差,且形成的闭合网格太少,削弱了林网的防护功能。从林网数量、分布以及成型状况等方面对防护林工程进行了宏观评价,指明了下阶段建设工作方向,为该区域防护林的管理和更新提供参考。

Taking the key construction area of the Three-North Shelterbelt Forest Program in northeast China as the research object,the ratio of belt to patch,connectivity,ring and dominance of the forest network were selected as the evaluation indexes.According to the principle of landscape ecology and geographic information system technology,the landscape index values of the actual forest network and those of the forest network in a reasonable state in 2021 were quantitatively evaluated and compared by using ZY-3 images with high resolution.The spatial distribution differences of landscape structure parameters of existing farmland shelterbelts were analyzed.The results showed that the number and area of shelterbelts in this area basically met the requirements of high-quality forest network,and the distribution was relatively uniform.However,the number of main and secondary forest belts was insufficient,the forming condition was poor,and there were too few closed grids.That weakened the protection function of the forest network.The Shelterbelt Forest Program was evaluated macroscopically from the aspects of the number,distribution and forming status of the forest network.The direction of the construction work in the next stage was pointed out.That provided the reference for the management and renewal of the shelterbelt in this area.