广西团水虱的种类组成及其对红树林的生态效应初探

为探究广西红树林区团水虱(Sphaeroma)的种类组成和分布特征,在广西北海、钦州、防城港3市的红树林区共设置30个调查断面并进行实地踏查,用随机取样的方式采集团水虱样品。调查结果表明:在广西红树林区共发现3种团水虱,分别为有孔团水虱(Sphaeroma terebrans Bate,1866)、光背团水虱(Sphaeroma retrolaeve Richardson,1904)和福建团水虱(Sphaeroma fujianensis sp. nov.)。30个调查断面中,有团水虱分布的断面有25个,其中有孔团水虱是广西红树林区域中的主要种类,分布最广,其次为光背团水虱,而福建团水虱仅发现于北海的3个断面。团水虱大多数分布于中低潮区的潮沟边缘或潮沟内以及林缘等地势较低的区域,在高潮区域分布较少。团水虱的蛀洞底质有桐花树(Aegiceras corniculatum)、白骨壤(Avicennia marina)、秋茄(Kandelia candel)、无瓣海桑(Sonneratia apetala)、木桩、软质沉积岩和聚苯乙烯泡沫等,表明其蛀洞底质多种多样。根据这些分布特征,本文讨论和分析了团水虱与红树林生态系统退化的关系,提出红树林是健康退化后才遭致团水虱侵害的假设。团水虱是否是侵蚀红树植物并导致大片红树林退化死亡的主因还有待进一步研究。

Preliminary Study on Species Composition of Sphaeroma and its Ecological Effect to Mangrove in Guangxi

To explore the species composition and distribution characteristics of Sphaeroma in Guangxi mangrove area, a total of 30 survey sections were set up in the mangrove area of the three cities of Guangxi Beihai, Qinzhou and Fangchenggang, and field surveys were carried out to collect Sphaeroma samples by random sampling. The results indicated that a total of three species of genus Sphaeroma were found in Guangxi mangrove, including Sphaeroma terebrans Bate, 1866, Sphaeroma retrolaeve Richardson, 1904 and Sphaeroma fujianensis sp.nov. There were 25 investigated sections where Sphaeroma inhabited among the 30 survey sections. S.terebrans which distributed most widely was the dominant specie in Guangxi mangrove area among the species we found. The secondary specie was S.retrolaeve, while S.fujianensis only occurred in 3 investigated sections of Beihai.Sphaeroma were mostly distributed at low-lying areas of the middle and low tide zone, such as the edge or interior of the tidal creek and the margin of mangrove forest, and was less distributed in the high tide zone.The substrates of Sphaeroma were Aegiceras corniculatum, Avicennia marina, Kandelia obovata, Sonneratia apetala,timber pile, soft sedimentary rock and Styrofoam, etc, which illustrated that their substrates were diverse. Based on these distribution characteristics, the relationship between the Sphaeroma and the degradation of mangrove ecosystem was discussed and analyzed, and the hypothesis that the Sphaeroma invasion occurred after the degradation of mangrove health was put forward. Whether Sphaeroma is the main reason that erode the mangrove and cause the degeneration and death of large mangrove remains to be further studied.