农田防护林多样性结构配置方式研究

Diversity structure distribution of shelterbelts

在各树种不同配置方式试验研究的基础上,提出了大面积农田林网杨树与其它树种的多样性与稳定性混交型构架,建立了各种混交林带.试验得出杨榆、杨柳混交的"对称式行混"(U P P U和S P P S)形式较佳,结构较合理;运用"边行效应原理"营造的林带,通过不同株行距试验对比,内行距为3m的林带树木胸径生长分化程度弱于内行距为2 4m的林带,而内行距为2m的林带树木胸径生长分化较为严重.

On the basis of different tree species distribution experiment, the authors present mixed shelterbelt models with system stability and tree species diversity. The results show that the symmetry mixed shelterbelts between rows have optimal effect in structure, growth and landscape heterogeneity,composed of Populus mixed with Ulmus (U-P-P-U), and Populus mixed with Salix (S-P-P-S). The growth differentiation of DBH in shelterbelts which are built with the distance of 3 m between mid-rows according to the principle of Edge Effect is less than that with the distance of 2.4 m between mid-rows, and 2.4 m less than 2 m as diameter is concerned.