济南城区绿地大叶女贞抗寒性分析与评价

Evaluation of Ligustrun lucidum Freezing Tolerance in Urban Green Space of Jinan

摘要: 针对2021年初济南市区两次强寒潮(−18.3℃)天气侵袭，采用全面踏查、典型抽样、样地详查的方法，采集了济南城区20处绿地大叶女贞冻害数据。通过引入树体冻损指数概念，构建其计算方法，采用聚类分析和主成分分析对大叶女贞抗寒性进行综合评价。结果表明，20处绿地大叶女贞冻损指数在77.39%~100.00%之间，均值达93.64%；通过聚类分析将20处大叶女贞划分为最轻、较轻、较重、严重4个冻损类型；主成分分析结果表明，位置效应是大叶女贞存活的关键指标，胸径10~15 cm，冠幅2~3 m的树体耐寒能力最弱；虽然济南大叶女贞90%以上受到严重冻害，但仍有零星栽培于4处调查点的19株几乎没有受冻害，其种源耐寒性极强，可作为北方耐寒性大叶女贞品种推广应用。

Abstract: In this study, the freezing damage data of Ligustrun lucidum in 20 different locations of urban Ji-nan were collected by the methods of comprehensive investigation, typical sampling and plot in-vestigation after two strong cold waves (−18˚C) in the year 2021. The concept of Tree Freezing Loss Index (TFLI) was introduced to calculation the plant’s freezing conditions for the comprehensive evaluation of cold resistance of Ligustrum lucidum by cluster analysis and principal component analysis. The results indicated that the value of TFLI of Ligustrum lucidum in 20 locations ranged from 77.39% to 100.00%, with an average of 93.64%. The result of cluster analysis divided the 20 locations into four groups by the lightest, lighter, heavier and severe damage grade. The results of principal component analysis showed that position effect (windward/leeward) was the key index for survival of Ligustrum lucidum in cold winter, the cold tolerance of Ligustrum lucidum was the weakest when DBH was 10~15 cm and crown width was 2~3 m. Although, more than 90% of Ligustrum lucidum was severely damaged by freezing in Jinan, 19 individual plants isolated from 4 locations were freezing tolerance without injured during the cold winter. These plants had strong cold tolerance which could be selected and applied as a cold-tolerant variety in northern China.