广东大峡谷常绿阔叶林主要植物种间关系、生态位及其群落稳定性研究

Study on Interspecific Relationship and Ecological Niche of Dominant Species and Community Stability of the Evergreen Broad-leaved Forest in Guangdong Grand Canyon

摘要:

探究特殊生境中常绿阔叶林主要植物的种间关系、生态位状态及群落稳定性，可为区域的生物多样性保育和自然保护地的保护管理提供科学依据。该文基于广东大峡谷森林生物多样性固定监测样地野外调查数据和2×2列联表，测定了主要植物的重要值、生态位宽度和生态位重叠，并应用方差比率法和χ²检验分析主要植物间的种间联结、OI指数、DI指数，并依据Godron法评价群落稳定性。结果表明，群落共记录104种植物，隶属于39科74属，其中木荷(Schima superba)的重要值和生态位宽度最大，华润楠(Machilus chinensis)、鸭脚木(Schefflera octophylla)、罗浮柿(Diospyros morrisiana)和黄杞(Engelhardia roxburghiana)次之，5种树在群落资源竞争中占据优势地位，并且与群落中其他植物产生了较高的生态位重叠(占总数的67.16%)。群落主要26优势种325种对中，负联结大于正联结。χ²检验结果表明种间相对独立性强，联结较为松散；但5种主要优势种间呈现紧密的关联性，相伴出现率大。Godron法分析表明，群落处于不稳定状态，群落物种间呈现显著负关联。因此，广东乳源大峡谷常绿阔叶林群落种间联结不强，群落不稳定，亟待加强保育和经营管理。

Abstract:

The research on the interspecific relationship, niche status and community stability of dominant plants in evergreen broad-leaved forests in special habitats can provide scientific basis for the conservation of regional biodiversity and the conservation and management of nature reserves. Based on the filed investigation data of long-term plots in Guangdong Grand Canyon and 2×2 correlation tables, the importance value, niche width and niche overlap of dominant species were determined. The index of interspecific associations, OI index and DI index for dominant species were analyzed by using variance ratio method and χ² test. Moreover, the community stability was evaluated by Godron method. The results showed that there were 104 species, belonging to 39 families and 74 genera, in which the importance value and niche width of Schima superba were the biggest, followed by Machilus chinensis, Heptapleurum heptaphyllum, Diospyros morrisiana and Engelhardia roxburghiana. These five species occupied a dominant position in the competition for community resources and had a high niche overlap with other plants in the community (67.16% of the total). In 325 pairs of 26 dominant species, negative associations were greater than positive associations. χ² test showed that the species were relatively independent and loosely connected. However, the five dominant species showed close correlation, and the concomitant occurrence rate was high. Godron method analysis showed that the community was in an unstable state and there was a significant negative correlation between species. Therefore, it was revealed that the interspecific association of the community in broad-leaved evergreen forests in Guangdong Grand Canyon had weak interspecific association and unstable community, which needs to be strengthened for conservation and management.