浙江西天目山古树树干健康状况及其随海拔梯度变化规律

古树作为组成和支撑森林和城市生态系统的重要组成部分，为各种动植物的生长提供了条件，为人类社会提供多种生态系统服务。分析古树树干腐烂及空洞状况沿海拔梯度的分布规律及其限制因素，有助于古树管理和保护策略的制定与实施。基于PICUS应力波树木断层图像诊断仪，本研究对浙江天目山国家自然保护区内不同海拔梯度上古树树干的腐烂及空洞情况进行了定量评估。共调研137株古树，结论如下：古树树干胸高断层处腐烂及空洞面积所占比例平均值为18.89%；古树树干腐烂及空洞面积占比在不同物种间存在一定差异；古树树干健康状况与海拔和气候因子之间存在一定的相关性，主要表现为随海拔升高，树干内出现腐烂及空洞的古树增多，且腐烂及空洞面积占比不断增大，这一相关性在不同树种之间也存在差异。

Health status of ancient trees and their variations along an altitudinal gradient in the West Tianmu Mountain,Zhejiang Province

As an important part of the forest and urban ecosystems, ancient trees support a large group of animal and plant species and sustain the critical ecosystem services for human beings. An understanding of ancient tree distributions along elevations and the limiting factors could contribute to ancient tree management and conservation strategies. In this study, 137 ancient trees of 11 species were surveyed using the PICUS Tree Tomography to investigate the ratios of decay and hollow area in ancient trees trunks. By analyzing the variations in the health status of ancient trees along the altitudinal gradient and the correlations with climate and tree size, we found that the ratio of decay and hollow area in the ancient tree trunks in Tianmu Mountain was 18.89%, the health conditions of ancient trees varied with species, and the health status of ancient trees showed significant correlations with the altitude. The ancient trees with decayed or hollow conditions in the trunks and the ratios of decay and hollow area increased with increasing altitude.