吉林水田防护林防风效能及其影响因子分析

对吉林省西部水田防护林10条典型林带的结构因子和防风效能进行调查，分析了林带结构因子与防风效能有效防护距离的相关关系。结果表明，林带结构不同，导致林带的防风效能差异显著，并且依据防风效能将水田防护林分为3类:Ⅰ（3、4、6、8）、Ⅱ（2、7）、Ⅲ（1、5、9、10），有叶期防风效能（E_有叶期）和无叶期防风效能（E_无叶期）较好的林带分别为第3、4、6、8条林带.林带的有效防护距离是-60～160 m。第3、4、6、8条林带结构的防风效能较好。防风效能与林带结构因子分析表明，枝下高、β_有叶期、β_无叶期与E_有叶期和E_无叶期呈显著正相关，胸径与防风效能呈负相关，而且其枝下高、β_有叶期、β_无叶期适宜值范围分别为4~7 m、0.31~0.39和0.63~0.75之间，胸径的适宜范围为＜32 cm。

Effectiveness of Windbreak Forest in Paddy Fields and Influencing Factors in West Jilin Province

Structure factors and windbreak effectiveness of ten typical paddy field shelterbelt structures in west Jilin Province were investigated. Correlations between the structure factors and effective distance of windbreak were analyzed. Windbreak effects at leaf stage (E_{leaf stage}) and windbreak effect at non-leaf stage (E_{non-leaf stage}) were determined. Due to the differences in structure，differences of windbreak effect of different paddy field shelterbelts were significant. The shelterbelts were divided into three categories: Ⅰ(3, 4, 6, 8), Ⅱ(2, 7), and Ⅲ(1, 5, 9, 10). The shelterbelts with the number 3, 4, 6, and 8 demonstrated high effectiveness of windbreak. The effective distance of shelterbelt was -60-160 m. In addition, correlation analysis showed that branch height, porosity at leaf stage (β_{leaf stage}) and non-leaf stage (β_{non-leaf stage}) had positive correlation with E_{leaf stage} and E_{non-leaf stage}, while diameter at breast high (DBH) had a negative correlation with them, and its branch height, β _{leaf stage} and β_{non-leaf stage} appropriate values were 4-7 m, 0.31-0.39 and 0.63-0.75, respectively, suitable range of DBH was<32 cm.