河北坝上农田防护林防风效能及类型配置研究——以河北省康保县为例

Research on Windproof Efficiency and Type Configuration of Farmland Shelterbelt in Bashang Region of Hebei Province——Taking Kangbao County as an Example

通过野外试验观测,对比分析了不同种类和林网结构农田防护林的防风效能,在此基础上提出了区域防护林优化配置建议。结果表明:综合防风效应和有效防护距离因素分析,对乔木农田防护林的综合防风效应进行评价:疏透型农田防护林>通风型农田防护林>紧密型农田防护林护林;在垂直方向上,三种疏透度的乔木农田防护林在不同高度上大体遵循随高度的增加防风效能逐渐下降的趋势。乔灌混交林、灌木防护林平均防风效能:榆树+柠条的乔灌混交林带21.5%>灌木防护林带20.5%,风速降低20%的有效防护距离分别出现在林后25H和12H。防护林建设方面乔灌木混交林应为首选;灌木防护林可布设在沙漠化严重的坡耕地或风口地带的农田;乔木防护林不是最佳的选择。

Through field test observations,this paper made a comparative analysis of the windproof performance of farmland shelterbelt in different types and structure.Optimal allocation recommendations of shelterbelts are proposed on this basis.The results show that windproof effects decrease in the order sparse transparent farmland shelterbelts>ventilated farmland shelterbelts>compact shelterbelt forest;In the vertical direction,the three kind sparse transparent tree shelterbelts at different heights generally follow this trend of increase of wind with height performance gradual downward.The average wind performance of mixed shrubs and bushes shelterbelts is elm +caragana shrubs mixed with 21.5%>20.5%shrub shelter belts.The effective protection distance for wind reduction by 20%appeared at Corinthians 25Hand 12H.Shelterbelt construction should be the preferred mixed shrubs;shrub shelterbelts can be laid in serious desertification of cropland or outlet strip of farmland;tree shelterbelts are not the best choice.