汕尾市城区古树后备资源组成和空间分布特征

古树后备资源保护是目前创建国家级、省级园林城市的重要指标之一，对生态保护和环境美化有极其重要意义. 通过汕尾市城区实地调研，分析了现有古树后备资源的组成结构、形态特征、重要值与空间分布等. 结果显示，古树后备资源共97株（隶属10科12属13种），均为广东乡土树种，且桑科（Moraceae）为优势科，其中细叶榕（Ficus microcarpa L. F.）为优势种，占古树后备资源的80.41%. 空间分布上，后备资源主要集中于115.34~115.37°E与22.79~22.80°N交叉处，数量和种数在经纬度上的分布均无明显差异. 基于调查分析结果认为，后备资源应当着重保护和扩大基数偏低的树种，同时平衡发展各区域后备资源数量，以缓解古树除册的风险.

Composition and spatial distribution characteristics of ancient tree reserve resources in Shanwei City district

The protection of ancient tree reserve resources is one of the important indicators of building a national and provincial garden city, which is of great significance to ecological protection and environmental beautification. Based on the field investigation in Shanwei City, this paper analyzes the composition structure, morphological characteristics, important value and spatial distribution of the existing ancient tree reserve resources. The results showed that there were 97 ancient tree reserve resources (belonging to 10 families, 12 genera and 13 species), all of which were native tree species in Guangdong, and Moraceae Ficus microcarpa L. F. is the dominant species, accounting for 80.41% of the ancient tree reserve resources. In terms of spatial distribution, reserve resources are mainly concentrated at the intersection of 115.34~115.37 °E and 22.79~22.80 °N, and there is no significant difference in the distribution of quantity and species in longitude and latitude. Based on the investigation and analysis results, it is considered that the reserve resources should focus on protecting and expanding the tree species with low base, and balance the number of reserve resources in various regions, so as to alleviate the risk of ancient tree de listing.