Predict By SVM And Grade Division Of Wild Plant Species With Extremely Small Populations’ Reintroduction Area In Hainan Island

On the basis of ((The saving and conservation program on extremely small populations in China》 which introduced by the State Forestry Administration of China in2011, Wild plant species with extremely small populations (PSESP) was defined as a kind of extreme endangered wild plant, and the species of geographical distribution in Hainan had24. In order to understand the field distribution of these species as soon as its effective protection, the study conducted a field investigation PSESP on the whole Hainan Island, and then summarized the status of the field distribution based on the findings; First proposed the use of support vector machine (SVM) model system to predict the method of its reintroduction area, and improved the selection method based on previous experience; Then, based on SVM model predictions, further connectivity assessment and optimization of PSESP reintroduction area in Hainan were made out by GIS system; Finally, based on the forest type distribution map of the different interference level of the human activities, the reintroduction area were done the corresponding grade division in accordance with the difficulty of the population reestablishment.The main experimental results are as follows:Conclusion1:There are24kinds of literature recorded PSESP in Hainan, Bulbophyllum hainanense, Sunipia hainanensis, Phaius hainanensis and Ilex kaushue, that the four kinds of species have not found in the field survey, But It was uncertain whether they already extincted or not in the field, further investigation should be made to reach a conclusion; Because of excessive human exploitation and utilization,20kinds of PSESP found in the survey were mostly concentrated in the non-protected areas with strong human activities, such as the roadside, forest edge and travel boardwalk in natural forests area of Hainan island, they were seriously endangered, and need urgent effective human protection.Conclusion2:Except for mangrove plants of special habitats, SVM model can be used to predict the reintroduction area of the species on Hainan Island if the effectively coordinate distribution point of PSESP were greater than or equal to3.It also need to introduce land-type data in the modeling data to predict the reintroduction area of mangrove plant. On the basis of free foreign shared Worldclim database, the model is very easily applied to predicte the reintroduction areas of other PSESP and endangered wild plants populations.Conclusion3:The connectivity of14kinds of PSESP reintroduction area were evaluated, and the degree of connectivity from low to high were.Chieniodendron hainanense, Michelia odora, Thrixspermum odoratum, Don’t is pulcherrima, Cymbidiun insigne, Horsfieldia kingii, Ceratostylis hainanensis, Hope a hainanensis, Paranephelium hainanense, Dendrobium sinense, Dendrolirhim tomentosum, Oxystophyllum changjiangense, Cymbidium eburneum, Dendrobium hainanense.Conclusion4:The optimization results of PSESP reintroduction area in Hainan showed that:PSESP in Hainan were mainly concentrated in the central and south-central mountain areas with less human disturbance and better habitat protection on Hainan Island. There was a positive correlation between potential distribution species and virgin forest areas, while virgin forest areas were not suitable for the main areas of population reestablishment, and the main areas of population reintroduction should be secondary forest areas, the shrubbery and open forest areas.Conclusion5:The reintroduction area will be divided into three grade regions according to the degree of the population reestablishment difficulty. Virgin forest areas of non-human disturbance were classified as level one, the difficulty of the population reestablishment was the smallest, in order to avoid secondary damage, the virgin forest were not recommend as main area of population reestablishment; Secondary forest areas, the shrubbery and open forest areas of human disturbance were classified as level two, the degree of the population reestablishment difficulty was the second, we recommended these areas as main area of population reintroduction; Plantations and other areas of serious human disturbance were classified as level three, the population reestablishment was the most difficult, habitat restoration and treatment here suggested to be the main methods of population reestablishment, and population reestablishment supplemented.Conclusion6:SVM prediction of the reintroduction area made up the blind area on the selection method of the reintroduction area, made the screening method of the reintroduction area more systemized and theoretied. Combined connectivity evaluation, optimization analysis and grade division of the reintroduction area, provided a complete case for the preliminary work for population reestablishment of PSESP and other endangered plant, made the the technical route of the population reestablishment more completed.