Ecological Study Of Keteleeria Davidiana Populations Of Yachang Forestry Farm In Nanpanjiang Basin

Keteleeria davidiana belonged to the Pinaceae family, which is evergreen tree species and endemic to China. Due to its high quality and beautiful shape, it has become an important and valuable timber tree species in China. At present, the population ecology research of Keteleeria davidiana is rarely reported. In this paper, the method of field survey and mathematics statistics was used to reseach on the K. davidiana in Yachang Forestry Farm, providding scientific theoretical basis for protection and sustainable management of Keteleeria davidiana natural forest. The results were as follows:(1)In Yachang Forestry Farm, three different altitudes of Keteleeria davidiana communities were basically the same in families, genera distribution types. Except the world distribution, the tropical distribution was the main type, especially in the pan tropical distribution. With the rise of the altitudes, the distribution of the tropical types decreased gradually, and the temperate distribution types increased gradually.(2) The important value of Keteleeria davidiana in three different altitudes showed inconsistent, decreasing with decreasing altitude.(3) The biodiversity in three different altitudes of Keteleeria davidiana communities was not consistent in various layers:In tree layer, Middle altitude community> Low altitude community> High altitude community; In the shrub layer and the herb layer, Middle altitude community> High altitude community> Low altitude community.(4) The co-existence of three different altitudes in Keteleeria davidiana communities were various in different layers:The co-existence were similar in the Middle altitude community and High altitude community, while in Middle altitude community and High altitude community were different in the Low altitude community.(5) The size structure was not complete in Keteleeria davidiana population under the different altitudes. Keteleeria davidiana pure forest belonged to the recession began type; Keteleeria davidiana mixed forest belonged to the growth type; Keteleeria davidiana mixed forest was a mature type; Keteleeria davidiana scattered forest was similar to a reverse J-shaped or stable type.(6) The tree height structure was unconsistent in Keteleeria davidiana population under the different altitudes:Keteleeria davidiana pure forest was major in Seedling Stage 1 and adult tree 7, 8.Keteleeria davidiana scattered forest was major in 1,2 of the seedlings and saplings. While the two mixed forests were dominant in Grade 1 seedlings,2?3 grade sapling and 4?5 adult trees, and the tree top distribution is relatively uniform.(7) The age structure of Keteleeria davidiana population under the different altitudes showed:Keteleeria davidiana pure forest and scattered forest disappeared in the young and old stages. The two mixed forests showed evenly in each age stages. Keteleeria davidiana scattered forest was major in young and middle age stages, especially in 1 to 3 age stages.Static life table showed that, four sample plots showed the same decreasing trend.Population survival curve of four sample plots were consistent, and the survival curves were between Deevey ? type and Deevey ? type.(8) The spatial distribution patterns of Keteleeria davidiana population under the different altitudes showed:Keteleeria davidiana pure forest was attributed to cluster distribution, Keteleeria davidiana mixed forest was ascribed to uniform distribution. However in different grid scale, the spatial pattern of Keteleeria davidiana population also changed. In the grid of 2mx2m scale and 4mx4m grid scale, Keteleeria davidiana pure forest changed from the uniform distribution to aggregation distribution, Keteleeria davidiana mixed forest from the aggregation distribution to the uniform distribution.(9) Natural regeneration survey showed that the regeneration of Keteleeria davidiana population mainly rely on seed breeding, following by sprouting reproduction.