Studies On The Standing Forestry Structure Of Pinus Massoniana Plantation In The Process Of Restoration

Pinus massoniana is a kind of pines which distributes most widely and has the lagest quantity.It is mostly used as timber wood, fulewood and pulpwood. It is also a canonical native nceddle tree species in subtropical zone east wet area in China, distributing in Guangdong, Guangxi, Hunan, Fujian, Hubei, Anhui, Sichuang, Guizhou, Henan, Shanxi, Jiangsu, Zhejiang, Jiangxi provinces and so on. Now the area of P. massoniana stands is the largest of needdle tree species in China. As one of the most representative forest s in south of China, P. massoniana has the advantages of good hardiness, growing fast, low cost, easy growth and being protected easily and so on. It is an important sylvicultural pioneer tree species in south of China. So researching on the characteristics of P. massoniana stand structure and community structrue is important for managing of P. massoniana plantation and improving commercial benefits and environment benefits.By using quantity statistical methods, P. massoniana stand structure and community structure in northwest in Fujian province were analyzed in this study, including the characteristics of stand structrue and community structrue of P. massoniana in different sites, densities and ages. The results were as follows:1) By analyzing and drying branches, stems, leaves and roots, the stand structure characteristics of P. massoniana in different sites were studied. The growing condition of 41-year-old P. massoniana plantations indicated that the effect of different sites on the growth of P. massoniana was in evidence. Taken the DBH for example, it could vary over 6 cm with the same density when planted, growing years and management but in different sites. The site condition should be considered fully for planting timber trees.2) By analysing woods, the stand biomass, stand root biomass, branch and leaf biomass and net products were estimated in different ages of P. massoniana, which showed that P. massoniana plantations of mature forest being cutted would get bigger commercial benefits. During the period from near mature forest to mature forest, the branch biomass increased, the height almost stopped growing after some extend, branch and leaf biomass decreased and root biomasss kept stable during the age increasing.3) By analyzing and drying branches, stems, leaves and roots, the stand structure characteristics of P. massoniana in different densities were studied. The biomass of DBH, stem, canopy, and root declined in different extents with the increasing of the density of crop, but the tree height was affected slightly.When the stand productive structure, leaf productive effort and standing crop were all considered, the density of 775 trees per hm was better in three densities.4) The community compositions of P. massoniana plantion under different sites were studied. The results showed that the undergrowth was simple. The diversity of undergrowth was increased with index of the site class increasing, which indicted that the higher of the site class index the higher of diversty. Geometric series index and Log series model were applied in the species abundance pattern of the undergrowth of the P. massoniana plantion under the different site conditions.5)The results of the study on characteristics of the woody community under P. massoniana plantation in different ages showed that species composition was different in woody community under P. massoniana plantation in different ages. Change of species composition occured with the growth of forest stand. However, species composition of herbage under P. massoniana plantation in different age was almost stable. Species diversity indices fluctuated in woody community under P. massoniana plantation in different ages. Species diversitiy of woody plant under the forest was not steady with development of the forest. Logarithmic series, geometric series and comminute model were used to fit comparative abundance species distribution of the tignosa under P. massoniana in different ages. The result showed the comparaticve abundance pattern of lignosa under forests changed with the forestation time. Base on the fitting results, the comparative abundance distribution pattern of lignosa species in P. massoniana plantation in different ages could be described by logarithmic series, geometric series and comminute model, exsecpcial the logarithmic series.6) The primary study was carried out about the changing of the composition, biodiversity, relative abundance of the undergrowth of P. massoniana plantion with different densities. The results showed that the dominant species of undergrowth with different densities was not obvious. The changing of diversity index and biomass showed the same trend, ie,D3> D1>D2.This indicted that the index of the biggest density stand was least. Broken stick model and log series model were fit to the species abundance of shrub layer, while the pattern of species abundance of undergrowth woody plant in D1 and D3 were agree with Log series model.