2018年1月初发生特大降雪后,对淮南市4种类型的城市绿地中树木雪灾受损情况进行了调查.将受损树木分为6个受损类型,确定所有胸径(地径)高于6 cm受损树木的受损等级;分析不同生长型(常绿/落叶)树种的受损特征,利用 Pearson 相关分析,分析胸径(地径)、树高以及树冠重叠度与树木受损之间的关系;计算不同树种受损指数,并利用单因素方差分析判断不同树种受损指数之间的差异.结果表明,调查范围内树木受损较严重,有23种5181株树木存在不同程度的受损,轻度受损、中度受损和重度受损个体占总受损个体比例分别为36.15%、44.53%和19.32%;生长型(常绿/落叶)是影响树木受损的重要因素,常绿树种在各个受损等级均高于落叶树种;随着胸径的增加,树木受损的比例先减小后增大,胸径(地径)与断枝少个体的比例呈极显著正相关(P＜0.01),与严重断枝或断梢和折断个体的比例呈极显著负相关(P＜0.01);树木的损伤比例随树高增大而降低,但断枝多、断梢等损伤程度高的比例有增加的趋势.矮树主要为压弯和折断,中、高树主要为断枝;树冠重叠度与树木中度受损呈显著正相关(r=0.824,P＜0.01),重叠度低的树木易发生压弯、折断和倒伏,重叠度高的易发生断枝.受损比例高于40%的6个树种间的受损指数差异显著(P＜0.05),香樟(Cinnamomum camphora)的受损指数最高(ID=0.42),与其他 5 个树种之间均存在显著差异.该研究对绿化树种的选择及突发暴雪灾害中树种的管理和保护具有一定参考意义.%The damage of landscape afforestation trees in 4 types of urban green space of Huainan City were investigated after the snowstorm of January 3, 2018. In the study, the damaged trees were grouped into 6 damage types, all the damaged trees with DBH (basal diameter, BD) above 6 cm were divided into 6 damage levels. The damage characteristics of the tree species with different growth types (Evergreen/deciduous) were analyzed, and the relationships between damage extent and DBH (BD) size, tree height (H) and overlap degree of crown (ODC) was also studied, respectively, by using pearson correlation analysis. Additionally, the differences in the calculated Damage Index (ID) among different tree species were analyzed by using One-way ANOVA. The results showed 5181 trees which belonged to 23 species had different degrees of damage, and the proportion of individuals with slightly damage, moderate damage and severely damage accounted for 36.15%, 44.53% and 19.32%, respectively; The proportions of damaged evergreen trees were greater than those of deciduous trees in various damaged grades which indicated that the growth form (evergreen/deciduous) was an important factor affecting tree damage. With the increase of DBH, the proportions of damaged trees decreased initially and then increased over time. The DBH (BD) sizes had significant positive correlations with the amounts of individuals suffered from slight branch loss (STB) (P＜0.01), but it showed significant negative correlations with the ratios of trees suffered from serious branch loss or crown broken (SSB & CB) and snapping (S). The damage rate of trees decreased with increasing of tree height, however, there was an increasing trend in the proportion of serious branch loss or crown broken (SSB &CB). Bending (B) and snapping (S) were the main damage types in short trees, but branch loss (STB, MEB) were the main damage types in both of the middle and high trees. The amount of individuals suffered from moderate damaged had significant positive correlations with overlap degree of crown (ODC) (r=0.824, P＜0.01). Trees with low overlap degree of crown was tended to bending, snapping and uprooted, but it was subjected to branch loss with high overlap degree of crown. The difference of calculated damage index among 6 tree species with the ratio of damage over 40% was significant (P＜0.05). Cinnamomum camphora had the highest calculated damage index(ID=0.42),which showed significantly difference with other 5 tree species.In present study, the snow-induced damage extent, characteristics of landscape afforestation trees was investigated, and the main factors that caused the different levels of damage were also explored. The results that obtained in our investigation would provide some references for tree species selection, the conservation and management of urban trees following the natural disturbances.
展开▼
