【摘要】 为研究宁夏地区农田防护林体系的生态效益 ,于 2 0 0 2年和 2 0 0 3年 8月 ,对宁夏地区农田防护林体系的疏透度、林网内风速、温度、湿度、农作物增产量等多项生态因子 ,进行了全面调查。采用综合疏透度和农作物增产量的综合权重指标分析表明 :大林网、多林带、多树种混交 ,利于防护林体系综合效益的提高 ,应是今后防护林建设的重点。对该地区农田防护林体系的生态效益研究表明 :农田防护林的防风效能在 35 %～ 4 5 %时较高 ,偏高或偏低时 ,防护效能都将下降 ,农田防护林体系特征 ,决定了林网内风速变化规律 ;农田防护林体系通过对太阳辐射的再分配 ,在地面、树体、树叶及作物表面使温度下降 4 0 %～ 6 0 % ,这种温度效益在宁夏地区具有防止作物被灼伤的作用 ;农田防护林网具有增加空气相对湿度和土壤含水量的生态效益 ,其作用机制与林带的防风功能密切相关更多还原

【Abstract】 Through the investigation on the structure and ecological benefits of shelter-belt on farmland in Ningxia and the analysis of comprehensive weight index, that the important roles played by large net, multi-shelter belt and mixed multi-tree-species in the construction of protection forests is explained. The results show that the wind protection effect of shelter-belt on farmland is better when its porosity reaches 35%～45% and its characters determine the law of variation of wind speed. By the redistribution of solar radiation, shelter-belt on farmland has prominent temperature effects on the surface of the soil and plant, which can prevent the crop from heating. Shelter-belt for farmland can increase air relative humidity and soil moisture. The mechanism is related to its wind control function.更多还原