侧柏古树后备资源健康评价体系的建立与应用

Establishment and Application of Health Evaluation System for Reserve Resources of Platycladus orientalis

古树后备资源指树龄50~99 a的城市园林树木,是古树的储备资源。为建立客观、科学的侧柏(Platycladus orientalis)古树后备资源健康评价体系,以西北农林科技大学北校区内23株侧柏古树后备资源为研究对象,采用主成分分析法遴选指标,利用层次分析法确定各个指标的权重,最后应用健康综合评价法对其进行评价。结果表明,西北农林科技大学的侧柏古树后备资源健康状况一般,处于亚健康状况的有19棵,健康侧柏仅有1棵,不健康侧柏有3棵;健康侧柏E3号生长势良好,胸径、树高年均生长量较高,根系分布较均匀,树干、枝叶无明显损伤;而不健康的W14号、W16号、W17号侧柏生长势较差,受相邻木遮阴影响严重,胸径和树高年均生长量较低;叶片、枝条和树皮枯损程度较大。本研究建立的侧柏古树后备资源健康评价体系,为古树后备资源健康管理提供科学依据,也为其他古树后备资源健康评价提供借鉴。

The reserve resources of ancient trees refer to the urban garden trees with the ages of 50 to 99 years,which are the conservation resources of ancient trees.In order to establish an objective and scientific health evaluation system of Platycladus orientalis reserve resources,in this paper,23 reserve resources of P.orientalis in the north campus of Northwest A&F University were studied.Principal component analysis was used to select indicators,then the analytic hierarchy process was applied to determine the weight of each indicator,finally,the comprehensive health evaluation method was adopted to conduct the evaluation.The results showed that the health status of reserve resources of P.orientalis in the campus was in general level,manifested by the fact that 19 P.orientalis trees were in sub-health level,1 in healthy(E3)and 3 in unhealthy(W14,W16,and W17)levels.Compared with others,E3 had better growth vigor,higher annual increment of DBH and tree height,more uniform root distribution,and no obvious damage in trunk and branches.W14,W16 and W17 had poor growth potential,they were seriously affected by the shade of adjacent trees,and had lower annual DBH and tree height growth;the leaves,branches and bark were damaged severely.The health evaluation system of P.orientalis reserve resources established in this study provides a scientific basis for the health management of reserve resources of ancient trees,and also provides a reference for the health evaluation of other reserve resources of ancient trees.