尖峰岭杉木人工林群落主要木本植物的生态位和种间联结

Niche and interspecific association of main woody plants in Cunninghamia lanceolata plantation community in Jianfengling,China

生态位与种间联结研究可揭示目标群落植物种间关系,为促进人工林向天然林转型发展提供理论支持。本研究基于海南热带雨林国家公园尖峰岭片区杉木人工林固定样地调查数据,分析群落重要值排名前20的主要木本植物的生态位与种间联结特征。结果表明:杉木人工林群落包含木本植物55科101属163种,群落物种组成复杂。作为建群种的杉木,其重要值及生态位宽度均为最高,占据群落绝对优势地位,与大多数木本植物都存在较大的生态位重叠与生态相似性,其中重叠程度最高的植物为海南杨桐。群落的生态位重叠与生态相似性均值分别为0.54和0.49,2种生态位指标的变化趋势基本一致,部分物种对资源的需求较为相似。主要木本植物的总体联结性表现为显著正联结,χ^(2)检验、联结系数、Pearson相关系数和Spearman秩相关系数显示,正关联种对的数量多于负关联种对的数量,但显著关联种对占比较低,反映出群落稳定性较强,物种能够稳定共存,多数物种间未形成紧密联系。综合来看,杉木抑制了热带天然树种的更新,可利用海南杨桐、岭南山竹子及鹅掌柴等对国家公园内的杉木人工林进行自然化改造修复。

Studies on niche and interspecific association can reveal plant interspecific relationship in the community,and provide theoretical support for promoting the transformation and development of plantation to natural forest.Based on Cunninghamia lanceolata investigation data of permanent plots of plantation in Jianfengling area of Hainan Tropical Rainforest National Park,we analyzed niche and interspecific association of the top 20 woody species in the community according to their importance values.The results showed that there were 163 species of woody species belonging to 101 genera and 55 families in the C.lanceolata plantation community,with complex species composition.As a constructive species,C.lanceolata had the highest importance value and niche breadth,and thus was the absolute dominant species in the community.It had a large niche overlap and niche similarity with many other species,among which the highest was observed in Adinandra hainanensis.The average niche overlap and niche similarity of the community were 0.54 and 0.49,respectively.The change trends of those two niche indicators were basically the same,indicating that some species were similar in resource demands.The overall association of main woody species was significantly positive.The χ^(2) test,association coefficient,Pearson correlation coefficient,and Spearman rank correlation coefficient suggested that the amounts of pairs with positive association were more than that with negative ones.The proportion of significant association species pairs was relatively low,indicating that the community stability was strong,species could coexist stably,and most species did not form close ties.On the whole,C.lanceolata had inhibited the regeneration of original tree species,and A.hainanensis,Garcinia oblongifolia,and Heptapleurum heptaphyllum could be used in natural transformation and restoration of C.lanceolata plantation in the Hainan Tropical Rainforest National Park.