在严重缺林的田界应努力营造大网格的防护林体系,带间距300—500米(为树高的20—25倍),与主风向相垂直,副林带间距约为主林带带间距的2倍。在营造时应考虑到防风林在夏天疏透度仍应保持50%,而不应形成相同高度的凸峰线。一般以三行防风林带为常见,中间一行是高 In severely tree-deficient fields, efforts should be made to create a large grid of shelterbelts with 300-500 m spacing (20-25 times the height of the tree) perpendicular to the prevailing wind direction, with subtropical forest spacing approximately equal to the main forest belt spacing 2 times. In the construction should take into account the permeability of the windbreak in the summer should remain 50%, and should not form the same height of the convex line. Generally three lines of windbreaks as common, the middle line is high