戴云山罗浮栲林主要乔木树种营养生态位研究

通过生态位空间分割,应用多维生态位宽度和生态位重叠分析戴云山罗浮栲(Castanopsis fabri)群落主要乔木树种在不同资源空间中的营养利用情况。结果表明,各物种在不同资源空间的营养利用情况存在差异。同一物种不同龄级生态位宽度不同,同一龄级不同物种生态位宽度也存在差异。罗浮栲天然林主要种群生态位重叠值介于0.2~0.3的有33对,占27.5%;大于0.3的有51对,占42.5%,群落中优势种种群生态位具有较大程度重叠,对资源的利用能力相似且竞争格局明显。乔木层中,个体多度分布较大的罗浮栲与其它树种生态位重叠在0.042~0.424,罗浮栲与其它物种在资源利用上所受到的竞争相对较弱,在一定程度上决定了该种群在群落中的优势地位。按照经典的分层频度分析,罗浮栲种群属于典型的衰退种,与群落演替的实际情况相一致。

Nutrition Ecological Niche of Dominant Arbor Species in Castanopsis fabri Forest in Daiyun Mountain

Based on the ecological niche space compartmentalization,the nutrition utilization status of the main arbor species of Castanopsis fabri community in different resource spaces in Daiyun Mountain Nature Reserve were studied by using their multidimensional niche breadth and their niche overlap rates.The results showed that the nutrition utilization of different species varied in different resource spaces,i.e.the niche breadths of the same species at different age class were different,and also did the niche breadths of different species at the same age class.There were 33 pairs of species with niche overlap rate ranged from 0.2 to 0.3,which acounted for 27.5% of the total species;and those of 51 pairs over 0.3 acounting for 42.5%.It revealed that the niche overlap rate of dominant populations was comparatively high with similar resources utilization ability,and the competition pattern among them was obvious.The niche overlap rate ranged from 0.042 to 0.424 between C.fabri and other species in tree layer,it indicated the competition to resource utilization between C.fabri and other species was low,and to some extent,it determined the population’s dominant place in the community.According to the classical layered frequency analysis,the C.fabri population belongs to the typical recession type of species,which is consistent with their actual community succession sequence.