尖峰岭热带山地雨林不同更新林的群落特征

Community Structure Characteristics of Tropical Montane Rain Forests with Different Regeneration Types in Jianfengling

基于对尖峰岭热带山地雨林原始林、皆伐后恢复41a的天然更新林和皆伐后恢复25a的人工促进天然更新林的调查数据,对其物种组成、物种相似性、物种丰富度及多样性、植株密度和稳定性等进行比较分析,并通过优势种群龄级结构分析预测群落的发展趋势。结果表明:1)物种丰富度及物种多样性均以原始林最高,乔木层物种多样性表现为天然更新林>人工促进天然更新林,幼树层和下木层表现为人工促进天然更新林>天然更新林;2)天然更新林与原始林的物种相似性比其与人工促进天然更新林的高,说明天然更新林恢复程度较人工促进天然更新林好;3)植株密度表现为人工促进天然更新林>天然更新林>原始林,与干扰程度正相关,与皆伐后恢复时间负相关;4)乔木层和下木层的群落稳定性表现为原始林>天然更新林>人工促进天然更新林;5)优势种群发展趋势分析表明,原始林群落主要优势种群大部分表现为增长或稳定趋势,天然更新林群落上层阳性树种表现为衰退或稳定趋势,下木层的优势种则表现为增长趋势,人工促进更新林的栽培种和一些偏阳性树种表现出衰退或稳定趋势,林下一些优势度稍低的种群表现出逐渐增长趋势。因此,虽然天然更新林和人工促进天然更新林所在群落具有一定的稳定性,但其种类组成结构将发生较大的变化,仍处在由前期阳性树种向后期耐荫树种转变的演替进程中。

The community structure characteristics were analyzed with the survey data from three plots which respectively were： a virgin forest （virgin forest, 0501 ）, a natural secondary forest after clear-cutting for 41 years （ nature secondary forest, 0502） and an artificial promoting secondary forest after clear-cutting for 25 years （artificial promoting secondary forest, 0503）. The community composition, species similarities, abundance and floristic diversity, individual density and stability were compared, and the community development trends were also predicted by the age structure analysis of the dominant populations. The results were listed as following： 1） 0501 had the most species abundance and floristic diversity. 0502 had higher floristic diversity than artificial promoting secondary forest in the arbor layer. 0503 bad higher floristic diversity than nature secondary forest in the young tree layer and the underwood layer. 2） 0502 had more similar species composition to 0501 than to 0503, which suggested that 0502 had better recovery than 0503. 3） The sequence of individual density was 0503 〉 0502 〉 0501, which was positively correlated with disturbance degree and negatively correlated with length of the recovery time after clear-cutting. 4 ） The community stability of the arbor layer and the underwood layer was 0501 〉 0502 〉 0503. 5） The development trends analysis showed that the dominant populations in 0501 tended to increasing or being stable. The intolerant trees of the arbor layers in 0502 tended to declining or being stable. While the dominant populations in the underwood layer had increasing trend. The cultivated species and some intolerant species in 0503 showed declining or stable trend while some populations in the underwood layer showed gradual increasing trends. Therefore, although some populations in both 0502 and 0503 tended to being stable trend. Their species composition and structure would change greatly and they were still in the succession process from the intolerant species in the initial period to the shade-tolerant species in the later period.