【摘要】 为进一步揭示北亚热带森林次生演替规律 ,于 2 0 0 2年 5月在定点样带上沿用前人的方法 ,对南京灵谷寺森林进行了群落调查。通过比较 195 1、1981、2 0 0 2年的定点样带资料 ,对灵谷寺森林的物种组成、多度、频度、重要值、种群结构以及物种多样性的动态变化进行了研究。 5 0多年来 ,群落中立木株数相对基本稳定 ,但空间分布异质性逐渐增加 ,而林下苗木和灌木个体数波动幅度极大 ,由 195 1年的 4 712株大幅上升至 1981年的 4 4 130株 ,到 2 0 0 2年又回落至 7372株。群落中物种数和建群种构成等都存在明显变化 ,物种数由 195 1年的 75种下降到 1981年的5 0种 ,2 0 0 2年又上升为 73种。物种多样性指数也存在波动 ,但目前尚未发现物种多样性指数有明显的上升或下降趋势。历经 5 0多年的次生演替 ,早期人工针叶林中的马尾松 (Pinusmassoniana)逐渐衰退 ,首先被阳性落叶阔叶树 ,如黄连木 (Pistaciachinensis)、枫香 (Liquidambarformosana)等取代 ,之后又被相对耐荫的栓皮栎 (Quercusvariabilis)等树种所替代 ,一些常绿树种成功入侵 ,人工针叶林经针阔混交林、落叶阔叶林 ,逐渐向地带性植被落叶 常绿阔叶混交林方向演替 ,其中立地条件较好地段的群落演替速度也较快。更多还原

【Abstract】 We studied 50 years of change in the species composition, abundance, frequency, importance value, population structure and species diversity of secondary subtropical forests in Nanjing Spirit Valley by comparing data collected along the same belt transects in 1951, 1981 and 2002. In general, the amount of stumpage was relatively steady over time, but the spatial heterogeneity increased. The number of under-story seedlings, saplings and shrubs changed significantly, increased from 4 712 in 1951 to 44 130 in 1981, and then decreased to 7 372 in 2002. Both species richness and dominance changed greatly. The number of species decreased from 75 in 1951 to 50 in 1981 and increased to 73 in 2002. The species diversity indices varied but there was no obvious increase or decrease over time. During over 50 years of secondary succession, the dominant species in the masson pine forest, Pinus massoniana, declined over time because of poor regeneration. It was first replaced by intolerant broad-leaved species, such as Pistacia chinensis and Liquidambar formosana, which were then replaced by relatively tolerant species, such as Quercus variabilis. Some evergreen species invaded successfully and were increasing in dominance. Artificial coniferous forests succeeded to coniferous and deciduous mixed forests, then to deciduous forests, and gradually to zonal vegetation —— deciduous and evergreen broad-leaved mixed forests. Communities on good sites were found to have faster successional rates of change.更多还原