热带北缘鹅凰嶂季雨林四种群落特征及成熟度分析

Characteristics and maturity level analysis of four communities in Ehuangzhang tropical monsoon forests of northern edge

为分析我国热带北缘季雨林的不同演替阶段的群落特征,该研究对广东阳春鹅凰嶂典型季雨林中4种(A、B、C、D)不同植物群落展开调查,对群落的物种组成、多样性和空间结构等进行分析,判断成熟度差异,预测演替方向,并提出优化建议。结果表明:(1)4种群落林层单一,小径级木与下层木占主体地位,具有1~3种明显的优势树种。(2)Shannon-Wiener指数为2.72~3.74,Simpson指数为0.90~0.97,Pielou均匀度指数为0.74~0.89,各群落多样性特征差异显著。(3)4种群落乔木胸径大小比数为0.49~0.51,角尺度为0.56~0.61,混交度为0.54~0.83,林分空间结构指数为60.57~71.44,林分空间结构距离为53.15~68.53。(4)综合群落基本特征、多样性和空间结构特征的分析得出,各群落的成熟度排名为D>A>C>B。综上认为,4种群落都处于演替前期或中期,乔木个体胸径和树高发展空间较大;群落整体处于中庸生长状态,个体均呈轻微聚集分布,树种表现为中度、强度或极强度混交,空间结构与理想林分存在一定距离。随着成熟度的增加,4种群落都继续以阳性树种作为主要优势树种进行演替,并初步具备该区域地带性顶极群落的典型植被特征;季雨林群落物种多样性提高,并向混交度增加、空间结构优化、稳定性增强的趋势演替。该研究结果为群落构建机制和森林结构优化等提供科学依据。未来应对该区域加强监管与保护,同时应对该地区的植被生态学和生物多样性保护展开广泛监测与深入研究。

To analyze the community characteristics of tropical monsoon forests with different succession stages,four different plant communities named A,B,C,and D were investigated in this study,respectively,in a typical monsoon forest of Ehuangzhang in Yangchun,Guangdong Province.The species composition,biodiversity and spatial structure were analyzed,their maturity levels’differences were detemined,succession direction was predicted,and suggestions for optimization were put forward.The results were as follows:(1)The forest layers of the four communities were single.Small diameter at breast height(DBH)class trees and lower forest dominated these communities,owning 1-3 obvious dominant species.(2)The Shannon-Wiener index ranged from 2.72 to 3.74,Simpson index from 0.90 to 0.97,and Pielou evenness index from 0.74 to 0.89,suggesting that their diversity characteristics were significant differences.(3)Their dominance ranged from 0.49 to 0.51,uniform angle from 0.56 to 0.61,mingling from 0.54 to 0.83,forest spatial structure index from 60.57 to 71.44,forest spatial structure distance from 53.15 to 68.53.(4)The analysis of community basic characteristics,diversity characteristics and spatial structural characteristics indicated that the maturity levels in all community ranked D>A>C>B.In conclusion,four communities are currently in the pre-or mid-term succession stages and the development space of DBH and tree height is large.The four communities are in the moderate growth state.All trees show a slight aggregated distribution,and the tree species are moderately,strongly or very strongly mingling.Besides,there is a distance in spatial structure between four communities and ideal forest with the development of maturity levels.The four communities continue to succession with intolerant tree species as the main dominant tree species,and gradually and preliminarily have the typical vegetation characteristics of the district forest climax community.With the development of maturity levels,the four communities’biodiversity and mingling will increase,the spatial structure will be optimized and the stability will be enhanced.The results of this study provide scientific basis for community construction mechanism and forest structure optimization.In the future,Ehuangzhang tropical monsoon forests should be more regulated and protected,while the ecology of vegetation and biodiversity conservation in the area should be widely monitored and studied in depth.