井冈山植物群落优势种空间分布格局与种间关联

摘要

为了解井冈山植物群落优势种的生存现状，对其空间格局和种间关系进行研究，并探讨保护策略。结果表明，重要值排前4位的优势物种，马银花(Rhododendron ovatum)、甜槠(Castanopsis eyrei)、黄丹木姜(Litsea longate)和石木姜(L. longatevar. faberi)的径级结构不同，垂直空间分布也存在明显差异。在检测的大部分尺度上，马银花、黄丹木姜和石木姜呈显著聚集分布，而甜槠呈随机分布。林冠上层物种甜槠只对林冠下层物种马银花在小尺度上(<6 m)存在正相关作用，甜槠在一定范围内为马银花的生长提供了庇护场所。大部分个体处于林冠中层的黄丹木姜和石木姜，在树冠能够接触到的范围内呈明显的竞争关系，在尺度9~13 m呈显著负相关分布。因此，井冈山植物群落优势物种间不存在显著竞争作用，若采取合理保护措施，植物群落的多样性水平还会继续提高。%In order to understand the survival situation of plant community in Jinggang Mountain, the spatial patterns and interspeciifc relationship of dominant species were studied, and the protection strategy was discussed. The results showed that four dominant species with top importance value, such asRhododendron ovatum, Castanopsis eyrei,Litsea elongateandL. elongatavar.faberi, had different size structures, as well as in vertical distribution. Based on relative neighborhood density index (Ωr) analyses, the spatial distribution ofRhododendron ovatum,Litsea elongateandL. elongatavar.faberishowed signiifcantly aggregated distribution at most scales, while that ofCastanopsis eyreiwas random distribution. The upper canopy speciesCastanopsis eyreihad only significant positive correlation with under canopy speciesRhododendron ovatumat small scale (<6 m), and Castanopsis eyreiprovide refuge forRhododendron ovatumwithin a certain range. However, mostLitsea elongate andL. elongatavar.faberiindividuals in the middle canopy had obvious competitive relationship, which the two species showed signiifcantly negative correlation at 9–13 m scale. Therefore, there were no signiifcant competition among dominant species in Jinggang Mountain communities. If taking reasonable and scientiifc protection, the diversity of plant community will continue to improve.