湛江特呈岛红树林植物群落的结构和动态特征

对特呈岛红树林植被进行多次和全面的调查,通过采用格子样的方法,选取面积为100～800 m^2的样地,每片样地再分成若干10 m×10 m的样方,对红树林样地内的植物进行每木测量,记录各植物的种名、胸径、高度、冠幅等,并进行重要性以及多样性等常规的群落分析,判定该地区植被的生长特征以及研究其演替动态变化。结果表明：①面积较大的群落主要有3个类型,即白骨壤群落（Avicennia marina）、白骨壤＋红海榄群落（Avicennia marina＋Rhizophora stylosa）、白骨壤-桐花树群落（Avicennia marina-Aegiceras corniculatum）;其它面积较小的群落有：白骨壤＋红海榄-木榄＋桐花树群落（vicennia marina＋Rhizophora stylosa-Bruguiera gymnorrhiza＋Aegiceras corniculatum）、红海榄＋木榄群落（Rhizophora stylosa＋Bru-guiera gymnorrhiza）;②在3个主要群落中,优势种的苗木和小树相对较少,优势种群的年龄结构均为衰退型;③各群落的Simpson指数关系为：白骨壤＋红海榄群落﹥红海榄＋木榄群落﹥白骨壤＋红海榄—木榄＋桐花树群落﹥白骨壤—桐花树群落﹥白骨壤群落;白骨壤群落的重要值为300,为典型的单优群落;④特呈岛的白骨壤群落是中国该类群落中面积最大的,目前长势良好,无病虫害,并且红树林外缘的白骨壤枝干在波浪冲刷或人为原因下,受到较严重的侵蚀,其幼树在林外缘基本无法存活,需要加强保护,对其生理生态学特征也值得进一步深入研究。

Structure and dynamic succession on mangrove communities from Techeng Island, Zhanjiang, Guangdong, China

In this paper,the mangrove communities of TeCheng Island in Zhanjiang city,Guangdong Province are investigated comprehensively.The mangrove forest is surveyed with a Lattice-like approach,from which importance and diversity are analyzed.The characteristics of vegetation and succession dynamics are discussed,with the following findings presented： ① The typical communities include three types,i.e.Avicennia marina community,Avicennia marina ＋ Rhizophora stylosa community and Avicennia marina ＋ Aegiceras corniculatum community;additionally,other smaller communities include Avicennia marina ＋ Rhizophora stylosa-Bruguiera gymnorrhiza ＋ Aegiceras corniculatum and Rhizophora stylosa ＋ Bruguiera gymnorrhiza.② Within the three primary communities,the age-structures of the dominant species all belong to the declining-type.③The ordering of the Simpson index within the different communities is found to be： Avicennia marina ＋ Rhizophora stylosa 〉Rhizophora stylosa ＋ Bruguiera gymnorrhiza 〉Avicennia marina ＋ Rhizophora stylosa-Bruguiera gymnorrhiza ＋ Aegiceras corniculatum 〉Avicennia marina ＋ Aegiceras corniculatum 〉Avicennia marina;the importance value of the Avicennia marina community is found to reach 300,making it a prototypical uni-dominant-species community.④The area of the Avicennia marina community on TeCheng Island is found to be the largest in China,owing to the absence of plant diseases and insect pests.However,as Avicennia marina is nearly incapable of growing in the exterior margins of the vegetation,it is very important to protect this community.In addition,the physiological and ecological characteristics of this community are worthy of further study.