Growth Characteristics Of Different Densities Camphor Plantation And Landscape Quality Assessment

Stand density is an important factor affecting the structure and function of the urban forest. For Shanghai urban plantation density is larger, the condition of forest decline phenomenon obviously, in order to analyze the density of urban plantation forest growth and forest stand structure, the influence of the different forest age of stand density effect. To explore the effects of density on the growth and stand structure and density mechanisms of different forest age benefit, and plantation self-sustaining mechanism, this study choose parks, forest parks and suburban areas for typical plots, the relationship between the growth characteristics of the initial seedling planted camphor crown for the study, a typical forest quad rat survey, survey of forest, forest analysis camphor, density and forest stand age and growth characteristics between levels-principal component analysis, a single wooden landscape, forest landscape, stand landscape typical plots of selected quality indicators to evaluate its landscape.The results showed that:(1) Most of the forest in Shanghai area camphor is in young forests, communities have not yet reached a steady state. In forest age between5-15a stand, have bigger influence on the growth of camphor wood density, stand growth to16a, density of less than800plants/hm2, the density of corresponding to reduce the influence of camphor forest growth, stand growth gradually to reach a steady state. In more than1000plants/hm2forest stand density, the density as the growth of the age, the influence of density on the growth larger.(2) Greater impact on the growth of low-density, community density and average diameter, average crown width between showing a significant negative correlation with increasing stand density, diameter was gradually decreasing trend, community density and average DBH, the relationship between the average crown was a significant negative correlation with increasing stand density, diameter was gradually decreasing trend. Different stand biomass in forest age difference was not significant, the size of the biomass is still gradually decreases with increasing density, but with the increase in forest age, the relationship between stand biomass and density smaller.(3) The fastest of Cinnamomum camphor DBH region about5a-20a, and then begin to decline; different density classes and age classes all increase first then to reduce the balance of the trend, some of which fluctuations in the growth plots at different age.(4) People take more attention on the crown shape, diameter distribution of tree canopy lines; stand density and forest age structure is relatively suitable ratio, the landscape can have a better quality of results; the lower of the density, the larger age of forest, the smaller of the density, the larger age of forest correspondingly.(5) It is the best forest landscape quality is large forest age (21a), low density (256/hm2), this age of stand density, tree crown type index is more reasonable, Trunk diameter ratio centered; In terms of forest landscape, tree diameter distribution of discrete degree is bigger, but the big diameter class more trees, undergrowth layer advantage degree is not high, bringing layer type less, low height, form unified landscape understory layer; For reunite landscape, canopy line ups and downs and canopy level more obviously (at least2layer), trunk significant degree is better.(6) With the increase of forest age, DBH growth increased, at the same time, the tree have differentiation, make the trees diameter distribution of discrete degree increase, because the artificial tending and the influence of forest self thinning density will be reduced. Through the landscape quality of different density, the score of the diameter distribution of discrete degree is bigger, forest landscape effect is good. Integrated forestry and ecology construction, therefore, cultivating different ages, different levels and low density, full crown, forests space empty stand structure type, can better meet the needs of construction of forest city from all directions.