| The mangroves are one of the special woody plant communities on the intertidal zones of tropical and subtropical coastal. They not only have the values of economy, recreation, education and scientific research and etc. but also give ecological services in coastal protection. Hainan Island is in the area of high incidence of typhoon, if there is no protection of mangroves, typhoon will bring about huge negative impacts on the development of economy and the life of residents in coastal area. It is an urgent and important issue to command the growth conditions of mangroves and develop mangroves with local conditions. In view of these, I described the mangrove forests of Hainan Island in the fields of plant taxonomy, community distribution, and ecological suitability regionalization. The main research results are as follows:1. The mangrove species of Hainan Island belong to the oriental mangroves group of the world, consisted of 20 families, 25 genera and 38 species, among them there are 12 families, 15 genera and 27 mangrove species (including 1 variety and 1 exotic specie), 9 families, 10 genera and 11 semi-mangrove species. There are 3930.3hm2 mangrove forests and 8 conservation districts, distributed mainly along the coast of Haikou, Wenchang, Sanya, Danzhou and etc.2. Basis on scale of the effect, the environment factors of Hainan Island can be divided into three parts: macroscopic, mesoscopic and microscopic. This paper preliminary studied the factors that influence the distribution of mangroves in Hainan Island by the methods of lateral contrast. The results showed that: macroscopic factors (e.g. climate, Ocean current.) decide the main trend of the mangroves distribution and growth environment; mesoescopic factors (e.g. landform soil and tide) influence on the plant community Structure. This paper focused on the distribution and regionalization of the mangrove in Hainan Island, for the microscopic factors influence the individual growth conditions, so the microscopic factors was not investigated yet3. Remote Sensing Images were use to abstracted the distribution of mangroves by, then investigated the mangroves of each county and conservation districts by the means of plot method. The results indicated that there are 11major mangrove communities, among them, the Avicennia marina (Forsk.)Vierh community is the most widespread one and occupied the largest area, Rhizophoraceae Stylosa Griff is the second; almost each with one dominant species in simple space structure with coverage rate 40%~90%,at height 2～7m. The typical ecological series and general succession disciplinarian of mangrove in Hainan Island are as following: form low tide to high tide and to sea shore, distribute in turn as Avicennia marina community, Rhizophora stylosa community, Aegiceras corniculatum community, Bruguiera gymnorrhiza community, Ceriops tagal community, Rhizophora apiculata community, Bruguiera sexangula community, Sonneratia caseolaris community, Excoecaria agallocha community, Nypa fruticans community, Heritiera littoralia community and semi-mangrove specie community. Because of the influence of the nature factor and the artificial factor, not all the regions have all above communities.4. Suitability Analysis and Cluster Analysis were performed to analysize the ecological suitability regionalization of the mangroves in Hainan Island; the survey data was analysized by spss15.0. The research suggested that: the coastal of the island can be divided into three areas: optimum areas including Lingshui Xinchun Yulin Sanya , suitable areas including Wenchang, Qionghai, Wanning, Dongfang Changjiang and a part of Danzhou, sequence suitable areas including Haikou, Chengmai, Lingao and a part of Danzhou.Summary, this article discussed the mangroves resource in Hainan Island in detail; and regionalized the mangrove forests about ecological suitable in Hainan Island based on main factors affecting the distribution of mangroves, then could give out the alternative suggestions for government on reconstruction and protection of the mangrove forests in Hainan Island...
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