人为干扰(采集)对闽楠群落优势种群生态位的影响

Effects of Human Disturbance(Collection) on Niche of Dominant Populations in Phoebe bournei Community

为了解人为干扰(采集)对闽楠(Phoebe bournei)群落优势种群利用资源和占据生态空间能力的影响,以广西富川县闽楠天然林为研究对象,通过样地调查,研究人为干扰对闽楠群落优势种群生态位宽度和生态位重叠的影响。结果表明,人为干扰下,闽楠在乔木层中的生态位宽度明显提高,在灌木层中大幅降低;乔木层优势种木荷(Schima superba)的生态位宽度受人为干扰影响不大,生态位重叠在干扰下变大,其生态位重叠值在蚌贝村委(BB)和白面寨(BMZ)2个群落中均为最大,远高于其他树种。综合分析表明,群落各层次优势种群的生态位对人为干扰的响应存在差异。乔木层优势种群的物种组成受干扰影响最大。人为干扰降低了乔木层和灌木层优势种群的生态位宽度,提高了草本层的生态位宽度;其对生态位重叠的影响则表现出与生态位宽度不同的变化趋势,人为干扰导致乔木层优势种群的种间竞争强度变大,不利于群落发展。

In order to know effects of human disturbance(collection) on ability of resources utilization and ecospace occupation of dominant populations in Phoebe bournei community, natural forests of P. bournei were used as objects in Fuchuan county, Guangxi. Based on field surveys, effects of human disturbance on niche breath and overlap of dominant populations in P. bournei community were investigated. Results showed that human disturbance caused significantly increase of niche breadth for P. bournei in tree layer and decrease in shrub layer.Affected by human disturbance, niche breadth of Schima superba in tree layer changed little, but overlap with other species increased with the largest niche overlap values in BB and BMZ communities, which were much higher than other species. Human disturbance had different effects on niche of dominant populations at different community levels and had the greatest impact on species composition of dominant populations in tree layer.Human disturbance reduced niche breadth of dominant populations in tree layer and shrub layer, which increased in herb layer. Effects of human disturbance on niche overlap showed different change compared with niche breadth. Human disturbance increased interspecific competition intensity of dominant populations in tree layer, which was not conducive to community development.