西门岛红树林沉积物细菌分布与环境特征

Bacteria distribution and environmental characteristics in the sediment of Ximen Island mangrove

为了解浙江省西门岛红树林沉积物的细菌分布与环境特征,2010年4月和11月,采集红树林(T1、T2站)和光滩(T3、T4站)中潮带0~2 cm、10 cm^12 cm和20 cm^22 cm层沉积物,培养计数异养细菌(HB)、反硝化细菌(DNB)、氨化细菌(AB)、无机磷细菌(IPB)和有机磷细菌(OPB);同时测定总有机碳(TOC)、总氮(TN)、总磷(TP)、氧化还原电位(Eh)、硫化物(S)及油类(Oil)含量;进行站位聚类分析和细菌与环境因子的相关性分析。结果显示:5类细菌在20 cm以上沉积物中均有分布,但0~2 cm层数量明显高于10 cm^12 cm和20 cm^22 cm层;HB、IPB和OPB数量均值无明显季节差异,而DNB和AB数量呈现秋高春低。聚类结果显示:春季,T1和T4站的相似度最高(93.3%),秋季,T1和T2站的相似度最高(94.6%),即红树林区沉积物细菌群落未与光滩区形成稳定差异。环境因子中,TOC、TN和TP含量因充足而未对细菌生长产生限制;而Eh(p=0.002)和Oil(p=0.034)对细菌分布的影响显著。本文综合分析细菌数量和碳、氮、磷元素分布特征认为,西门岛红树林生态系统与我国大面积长时间自然生长的红树林生态系统仍存在差异。

In order to know the distribution characteristics of bacteria in the sediment of Ximen island mangrove and also to analyze its similarities and differences compared with other mangroves, the author conducted culture counting of heterotrophic bacteria（ HB ）, denitrifying bacteria（ DNB ）, ammonifying bacteria（ AB ）, inorganic phosphorus bacteria（IPB） and organic phosphorus bacteria（OPB） in 0 - 2 era, 10 cm - 12 cm and 20 - 22 cm layers of middle intertidal zone in the mangrove sediment （T1 and T2） and mudflats （T3 and T4） of Ximen Island in April and October, 2010 respectively. Meanwhile, total organic carbon （TOC）, total nitrogen （TN） and total phosphorus （TP） were measured in every sample; oxidation -reduction potential （Eh ）, sulfide（S） and oil in autumn samples were measured in addition. Based on these, cluster analysis among stations was carried out and relationship between bacteria distribution and environmental factors were analyzed. The results showed that all of the five kinds of bacteria exist in the 0 - 20 cm layer of middle intertidal sediment of Ximen Island and the number of bacteria in layer 0 - 2 cm holds much more than that in layer 10 - 12 cm and 20 - 22 cm. For 0 - 2 cm layer, there was no obvious seasonal difference in the number of HB ,IPB and OPB, while the number of DNB and AB in autumn were more than those in spring. The result of cluster analysis was that similarity between T1 and T4 was highest （93.3%） in spring, while in autumn T1 and T2 were mostly similar （94.6%）. It therefore can be concluded that there had not been obvious difference in bacteria community between the mangrove sediment and mudflat. The result of relationship analysis dem- onstrated that TOC, TN and TP did not impose restrictions on the growth of bacteria due to their comparatively abun- dant content in spring and autumn while Eh（p =0. 002） and Oil（p =0.034） were the factors that affected bacteria distribution significantly. The author＇s final conclusion is that there exists difference between Ximen Island mangrove ecosystem and the natural mangrove ecosystem with wild expanse.