关键词: 紫色土, 植被恢复, 微生物群落, 衡阳, 功能多样性

Abstract: Old ginkgoes with age ≥100 years are main components of large old trees in central Jiangsu, providing vital ecosystem services. It is significant to understand quantitative population characteristics of such old ginkgo trees by population inventory within a certain area. The static life table of old ginkgo population in Nantong of Jiangsu Province was compiled by applying age class structure represented by diameter at breast height (DBH) classes and smoothing technique. There were 282 individuals of old ginkgo trees, with the sex ratio of female to male being 1.37. Most of the old trees were distributed in the southwest of Nantong. The population of old ginkgo trees showed inverseJ size distribution, and its survival curve trended to the type of Deevey0Ⅱ. There was a fluctuation of life expectancy for the whole population. The life expectancy of the second age classes was relatively low. The mortality rate curve and disappearance rate curve in the lifespan had similar variation trend, with the peaks in the 2nd and 4th age classes. Due to long life span with severe fragmentation in the distribution of those old trees, it is suggested to improve their habitat quality and strengthen protection in concentrated areas of Nantong, especially for the individuals after the 5th age classes.

Key words: functional diversity, re-vegetation, microbial community, Hengyang., purple soils