| In order to provide a basis and reference for the vegetation ecological improvement of the plantations, and expound the vitality and health status of Pinus massoninana plantations at present, then, offer some elementary analysis and suggestions for the operators, and reference for the assessments of forestry. The mainly research object of the study was the Pinus massoninana plantations in Zijinshan Forest of Hunan Hengshan. The author adopted the method of space substitute time, sited a standard plot in the plantations of each age stages to study the species diversity in the communities, used the method of functional key performance indication of composite structure, to build the stand's vitality and healthy assessment indicator system of Pinus massoninana plantations, structured by3criteria-population vitality of Pinus massoninana, ecological health of vegetation type, and resistance vitality of stand, and14Index hierarchys affiliated. The diverse phases of cultivation of Pinus massoninana plantations in Hengshan Mountain was taken as sub-compartment samples to evaluate,15of which, with5distinct growing stages, were put in stand vitality and health assessments. By using the principal component analysis method, obtained the key factors for the stand's vitality and health of Pinus massoninana plantations through the analysis of indicator data, then verified the effectiveness of the key factors. The results were as followed:1. Different stages of Pinus massoninana secondary plantations investigation of108kinds of plants species,56families under91genera, in Zijin Mountain National Forest, Hengshan County, Hunan Province. Loropetalum chinensis, Quercus fabri, Radix Syzygii, Gardenia jasminoides and Imperata cylindrica, Schizachyrium scoparium, Lophatherum gracilie and Woodwardia japonica have a greater advantage in the whole community. Before the mature forest (15years), the index value of the entire community and its diversity is very volatile. New species of wild trees appeared after the mature forest (15years), while the index value of the whole community tend to stabilize. Throughout the evolution of the communities, the species similarity is lowest(Sm of0.158) between communities of old growth forest (25years) and young forest (5years), β diversity the most, reflecting the young forest (5years) is the most unstable community.2. The stand's vitality and healthy assessment indicator system of Pinus massoninana plantations has been structured. The total stand's vitality and healthy conditions of masson pine plantations are in a sub-healthy state, including15sub-compartment samples. Moreover, it was apparent that the H-value of population vitality of5,10, and15years were more higher than those of2and25years. Besides, principally focused on the sub-compartment samples aging2and25years were in healthy state, the ecological conditions of vegetation type were dissimilar in each sub-compartment samples. However, there was little distinction in resistance vitality conditions between sub-compartment samples, and all of them were in a sub-healthy state, consistent in the total plantation.3. Stand flammable index, the main road distance index, Shannon Wiener index, species richness, pest and disease index were great positive role in promoting the vitality and health of Pinus massoniana plantations, the5factors were determined to be the vitality and health key factor for Pinus massoniana plantations. By analysing the meaning of the factors, proposed that Pinus massoniana plantations which in good vitality and good health should have a high fire protection capacity, subjected to a smaller interference of no business purpose, evenly distributed and a large number of species of understory vegetation communities, and moreover, there was no serious plant diseases and pests. |
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