西双版纳望天树林主要树种的竞争关系研究

Study on the Competitive Relations of the Main Tree Species of Parashorea chinensis forest in Xishuangbanna

以西双版纳热带雨林的5块望天树林样地为研究对象,采用Voronoi图的方法确定竞争单元,选择V-Hegyi竞争指数对其中的14个主要树种的竞争关系进行了分析。结果表明,在望天树林中,种内竞争明显小于种间竞争,种内竞争占总竞争的19%,种间竞争占总竞争的81%。按竞争指数大小将种内竞争强度分为3个级别,假海桐种内竞争最激烈,其次是望天树,其余树种竞争强度较弱。在种间竞争中,处于群落上层的望天树不仅个体多,且径级大,在林内资源的利用上最占优势,是其他树种的主要竞争者。假海桐处于乔木最下层,被其他树种干扰程度最大,其种间竞争也最激烈。总竞争强度的排序为假海桐>望天树>木奶果>金钩花>蚁花>滇南溪桫>毒鼠子>云树>大花柃>绒毛番龙眼>山韶子>尾叶榕>网脉肉托果>木莲。

By selecting Voronoi diagram method for determining the competition unit, V-Hegyi competition index was chosen for analyzing the competition ralation of 14 main tree species in 5 Parashorea chinensis forest samples located in Xishuangbanna tropical rainforest. The results showed that intraspecific competition is much smaller than interspecific competition in Parashorea chinensis forest, intraspecific competition accounted for 19 % of total com- petition, interspecific competition accounted for 81% of total competition. Based on competition index, intraspecific competition intensity could be divided into three levels, intraspecific competition of Pittosporopsis kerrii was the most competitive, followed by Parashorea chinensis, competition of the rest tree species was the lowest. In terms of interspecific competition, Parashorea chinensis, located in upper part of the whole community, not onXy had the large number of individuals, but also big diameter magnitude, and it was in an advantageous position in resource utilization and was the main competitor for other tree species. Located in the lowest part of the whole tree layer, and intensively disturbed by other tree species , the interspecific competition of Pittosporopsis kerrii was also intense. The sorting of total competition intensity among different tree species was Pittosporopsis kerrii 〉 Parashorea chinensis 〉 Baccaurea ramiflora 〉 Pseuduvaria indochinensis 〉 Mezzettiopsis creaghii 〉 Chisocheton siamensis 〉 Dicha- petalum gelonioides 〉 Garcinia cowa 〉 Eurya magniflora 〉 Pometia tomentosa 〉 Nephelium chryseum 〉 Ficus hetero- pleura 〉 Semecarpus reticulata 〉 Manglietia fordiana.