海南鹦哥岭广东松(Pinus kwangtungensis)群落优势种群的生态位

Niche Characteristics of Dominant Populations in Pinus kwangtungensis Community in Hainan

采用植物群落调查法,在海南鹦哥岭选取3个广东松样方,分别为1,2,3号,佳西岭选取1个样方,为4号样方,每个样方为60×60 m,取样面积共14 400 m2,对广东松群落优势种群的生态位关系进行比较研究,结果表明:(1)在4个样方中,广东松种群的生态位宽度分别为2.101 4(样方4)>1.601 6(样方1)>1.444 1(样方2)>1.170 1(样方3),广东松在4号和3号样方中分别具有最强和最弱的环境适应力和竞争力。(2)4个样方中广东松与其他优势种群的生态位重叠程度与生态位宽度大小的排序一致,分别为样方4>样方1>样方2>样方3,其中,广东松在4号样方中与其他优势种群的生态位重叠最高,受其他优势种群的竞争和排挤最严重。(3)各样方生态位高度重叠的种对分别占到总对数的85%,84%,71%和84%,群落物种在资源和生存空间的利用上产生了较高的生态位重叠。结果说明,现阶段海南的广东松群落种间在生境和资源的需求上具有较高的相似性,群落物种生态位分化不明显,在资源利用上存在较大竞争,仍是一类介于针阔混交林和常绿阔叶林之间的不稳定过渡群落。

Pinus kwangtungensis is a special species of conifers in China,mainly distributed from the north tropics to the north pan-tropics. As P. kwangtungensis was distributed in the southernmost area in China it is of a great scientific value and practical significance to analyze the coexistence mechanism of community species,the community structure and stability of P. kwangtungensis forest. Four sample plots or quadrats were established:three from the Yingge Mountains and one from the Jiaxi Mountains,with a total land area of 144 00 square meters,6 060 m each plot,to make a comparative study in dominant population niche and inter-specific associations. The results showed that the niche breadth of P. kwangtungensis population in the four plots was in the order of Plot 4( 2. 101 4) > Plot 1( 1. 601 6) > Plot 2( 1. 444 1) > Plot 3( 1. 170 1),indicating P. kwangtungensis in Plot 4 had the highest adaptation and competition but the lowest in Plot 3. The niche overlap of P. kwangtungensis and other dominant populations in the four plots was similar to the niche breadth in the order of Plot 4 >Plot 1 > Plot 2 > Plot 3. In Plot 4 the P. kwangtungensis population had the highest niche overlap with other dominant populations and hence competed and excluded most seriously with other dominant populations. The pairs of the species with high niche overlap in each plot contributed 85%,84%,71% and 84% to the total pairs of the species,and the species in the community had a very high niche overlap in their use of the resource and living space. The results showed that the P. kwangtungensis community had a high interspecific similarity in requirements of the species for habitat and resource in Hainan,and that the species in the community did not have a high niche differentiation and had a high competition in use of the resources,indicating that this community was still an instable and transitional community from the needle and broad-leaved mixed forest to the evergreen broad-leaved forest.