塔克拉玛干西南缘风沙前沿防护林对条田的防护作用

Protective Effect of Shelterbelt on Strip Fields in Southwest Margin of Taklimakan Desert

[目的]研究不同疏透度防护林对塔克拉玛干沙漠绿洲边缘条田的防风效能,为当地网格条田可持续发展提供理论指导。[方法]选取塔克拉玛干南缘县城——新疆叶城县恰其库木管理区城郊防护林为研究对象,通过野外实地观测,对比研究不同疏透度防护林对塔克拉玛干沙漠绿洲边缘条田的防风效能。[结果]①叶城县恰其库区防护林内条田里离防护林10—15 m范围是防风效果最佳区域,可种植防风能力较差农作物。②3种结构防护林总体而言,防护林1.5 m高处防风效能最佳,2 m处防风效能最低。本研究区条田内,种植生长期总株高小于1.5 m以下的农作物,可有效避免风害导致的损失。③疏透结构林带固沙效率最佳,通风结构次之,紧密结构林带固沙效率最差,其固沙效率排列顺序为:58.39%>57.99%>36.29%。[结论]要发挥防护林的固沙作用,林带疏透度应控制在疏透结构为宜,可以使其达到较好的防风效果。疏透结构防护林周围的条田内可种植抗沙能力较弱农作物。

[Objectives]The windbreak efficiency of shelterbelts with different permeability on strip fields at the edge of the oasis in the Taklamakan Desert was analyzed in order to provide theoretical guidance for sustainable development of local grid strip fields.[Methods]The peri-urban shelter forest in the Qiaqikumu area of Yecheng County,Xingjiang Wei Autonomous Region on the southern edge of the Taklamakan Desert was selected as the research location.Field observations were made to quantify the windbreak effect for shelterbelts with different structures on the edge of the Taklamakan Desert oasis.[Results]①The strip field within 10—15 m of the leeward side of the shelterbelts in the Qiaqikumu area of Yecheng County experienced the best windbreak effect.Crops with poor ability to withstand wind damage can be planted in this strip field.②In general,the windbreak effect provided by shelterbelts was highest for plants with a height of 1.5 m and lowest for plants with a height of 2 m.Therefore,planting crops with a plant height of less than 1.5 m in the shelterbelts can effectively minimize losses caused by wind damage in this study area.③The sand fixation efficiency of the open-structure shelterbelt was the greatest,followed by the ventilated-structure shelterbelt.The sand fixation efficiency of the compact-structure shelterbelt was the worst.The order of sand fixation efficiency for the three kinds of structural shelterbelts followed the order of 58.39%>57.99%>36.29%,respectively.[Conclusion]In order to increase the sand-fixation efficiency of shelterbelts,open-structure shelterbelts should be recommended.This shelterbelt type can achieve the best windbreak effect.Strip fields around open-structure shelterbelts can be planted with crops having weak sand resistance.