鱼藤在红树林中的扩散规律初探

Dispersal Pattern of Derris trifoliata in Mangroves

为了解鱼藤(Derris trifoliata Lour.)在红树林中的扩散规律,选择位于海南省和广东省的3个红树林分布区为研究区域,研究鱼藤在红树林中的扩散速率以及攀爬物和群落类型对鱼藤扩散速率的影响。首先利用Google Earth得到2015—2019年研究区域的遥感影像,结合实地调查结果,确定不同年份鱼藤分布面积,并计算扩散速率;通过实地调查得到鱼藤生境的红树林群落类型,并在实验室开展攀爬物对鱼藤生长速率影响的对比实验。结果表明:鱼藤的扩散速率(分布面积变化率)与鱼藤扩散的初始面积呈极显著负相关,与初始周长面积比呈极显著正相关;攀爬物的支撑使鱼藤地径和株高有显著增加;不同红树林群落类型中鱼藤分布面积占比不同,其排序为桐花树(Aegiceras corniculatum)>无瓣海桑(Sonneratia apetala)>海莲(Bruguiera sexangula)>秋茄(Kandelia obovata)>白骨壤(Avicennia marina)>木榄(Bruguiera gymnorhiza)>海漆(Excoecaria agallocha)>红海榄(Rhizophora stylosa)。

In order to explore the dispersal mechanism of Derris trifoliata in mangroves,3 mangrove distribution areas in Hainan and Guangdong Province were selected as the research area to study the dispersal rate and the impacts of climbing objects and community types on the dispersal rate of D.trifoliata.Firstly,the images of the study area from 2015 to 2019 were obtained by using Google Earth,then the distribution characteristics of D.trifoliata in different years were determined and the dispersal rate was calculated combined with the results of field surveys.The types of mangrove communities in the habitat of D.trifoliata were identified according to the field survey,and the experiment of the climbing objects on the growth rate of D.trifoliata was carried out in the greenhouse.The results showed that the dispersal rate(change rate of distribution area)of the D.trifoliata had a very significant negative correlation with the initial area of D.trifoliata and a very significant positive correlation with the initial perimeter area ratio.Climbing objects have a significant impact on the ground diameter and height of the D.trifoliata.The order of the percentage of D.trifoliata area in the investigated mangrove communities follows as:Aegiceras corniculatum>Sonneratia apetala>Bruguiera sexangula>Kandelia obovate>Avicennia marina>Bruguiera gymnorhiza>Excoecaria agallocha>Rhizophora stylosa.