Study On Habitat Characteristics And Regionalization Of Cyclobalanopsis Glauca Natural Forest Community In Zhejiang Province

On the basis of understanding the vegetation habitat,it is of great significance to develop the niche and inter-species relationship within the community to understand the function and characteristics of the ecosystem.In this study,423 plots in the natural forest of Cyclobalanopsis glauca in Zhejiang Province were used to sort the TWINSPAN classification and the Canonical Correspondence Analysis(CCA)method in quantitative ecology,and to analyze the habitat characteristics and interspecific associations.The relationship between the distribution pattern of forest communities on the gradient of habitat conditions and various environmental factors.In addition,the MaxEnt niche model was used to simulate the suitable bioclimatic conditions and planting zoning of Cyclobalanopsis glauca,in order to provide a theoretical basis for the improvement of forest quality and the development of precious tree species in Zhejiang Province.The main findings are as follows:(1)There are 233 species of 197 genera and 59 species in the study area.According to the important values,the main dominant species are Pinus massoniana,Cunninghamialanceolata、Cyclobalanopsis glauca,Loropetalumchinense,Phyllostachys heterocycla,Schimasuperba,Castanopsissclerophylla,Lithocarpusglaber,Castanopsiseyreiand Quercus fabri.The typical habitats of Cyclobalanopsis glauca in Zhejiang Province are estimated by the important values of environmental factors:the altitude is between 50-700m,the slope is between 20°-45°,and the soil type is red soil.(2)The niche breadth in the community of Cyclobalanopsis glauca is in the order of masson pine,Chinese fir,Cyclobalanopsis,Schimasuperba,Aralia elata,Phyllostachys pubescens,Tartary buckwheat,Dendrobium,Sweet sorghum,and White peony.The niche breadth of Cyclobalanopsis glauca is the same as that of Masson pine and wood.The top three in the Netherlands indicate that their ecological adaptability is stronger than other tree species.The niche overlap values of Cyclobalanopsis glauca and Pinus massoniana,Cyclobalanopsis glauca and Schimasuperba were all greater than 0.8,indicating that Cyclobalanopsis glauca,Schimasuperba and Pinus massoniana have similar resource utilization ability,or exist in complementary conditions.Preliminary analysis of interspecific association showed that Cyclobalanopsis glauca has a very significant positive correlation with Chinese fir,Masson pine and Schimasuperba.In the inter-species relationship,Cyclobalanopsis glauca and the dominant species of each cluster have common needs for photothermal conditions.(3)Using TWINSPAN,the Cyclobalanopsis natural forest community in the study area can be divided into 7 clusters.The CCA ranking shows that the environmental factor with the highest correlation coefficient between the nine environmental factors and the first axis is the soil type,and the correlation coefficient is 0.2139.The correlation between the second axis and altitude is the strongest,and the correlation coefficient is 0.2283.Altitude,slope and soil type mainly affect the distribution of Cyclobalanopsis natural forest communities.(4)Based on MaxEnt niche model and ArcGIS,the suitable distribution area of Cyclobalanopsisglauca in Zhejiang was simulated.The average AUC value of 15 simulations was 0.8343,and the standard deviation was 0.0287,indicating that the model has a high simulation level and the prediction is high.Credibility and reference value.The simulation results show that the suitable area of Cyclobalanopsis glauca in Zhejiang Province is mainly distributed in the northwestern part of Zhejiang Province.It is from the Baiji Mountain-Tianmu Mountain Range in the north to the south,the Qianligang-Longmen Mountain area,the Huishan Mountain area,and the Xianxia Ridge-Dapan Mountain.A zone and surrounding area.Among them,the most suitable area is mainly located in the Tianmushan-Baijishan-Longmenshan triangle block in the most northwestern part of Zhejiang.Most of the Cyclobalanopsis glauca distribution points are located in their high-yielding areas.The probability of occurrence of Cyclobalanopsis glauca is mainly affected by the average temperature and monthly difference,the most dry monthly precipitation,the most dry season precipitation,and the coldest season average temperature.