Response Of Tree Growth To Climate Change Based On Tree Ring Characteristic From Nondestructive Measurement

The relationship between climate change and tree ring data is of great significance in the study of global climate change.Tree ring data has been widely used to evaluate the relationship between tree growth and environmental factors due to their advantages of accurate dating,strong continuity,high resolution and easy access to multiple copies.In this study,tree ring data of living trees from six tree species were collected with Resistograph（?）non-destructive measurement technology,the growth models for each species were established,and the relationship between climate change and tree ring data was summarized and discussed,so as to reveal the influence of meteorological change on the growth and development of various tree species in the study area,and lay a foundation for further research on the relationship between tree ring data and climate in the future.The main conclusions of the study are as follows:1.Through the wood disc of stem analyze,it is proved that the measurement accuracy of Resistograph resistance meter for coniferous trees is higher than that of broad-leaved trees,and the tree ring characteristic data with higher precision can be obtained by pointing the trace of resistance meter probe to the tree center.The moisture content of wood has a negative correlation with the measurement of the Resistograph.2.In this study,there were six tree species from the study area:Metasequoia glyptostroboides,Taxodium ascendens,Pinus massoniana,Koelreuteria paniculata Laxm,Eucommia ulmoides and Platanus acerifolia.There was no significant difference in the tree ring characteristics of east-west and north-south directions.After principal component analysis,coniferous and broad-leaved tree species were well distinguished by their width and density characteristics.3.Through the optimization of growth equation,the optimal model was selected for the growth of the ring width of the six tree species.Based on the calculation of the model,the maturity age of the six tree species was obtained as follows:Metasequoia glyptostroboides 28years,Taxodium ascendens27 years,Pinus massoniana 20 years,Koelreuteria paniculata Laxm23 years,Eumoides 18 years and Platanus acerifolia 60 years4.The correlation between tree ring width（RD,ED,LD）and ring density（RW,EW,LW）of six tree species with annual meteorological factors(YT,YT_min,YT_max,YP,YRH,DP_max)showed that:YT_min had the greatest influence on the ring width index of Metasequoia glyptostroboides and Taxodium ascendens,temperature had the greatest influence on the ring width index of Pinus massoniana,and YT and YT_min had the greatest influence on the ring width index of Koelreuteria paniculata Laxm.YT_max was the main factor affecting the growth of ring density of Metasequoia glyptostroboides and Taxodium ascendens,and YT_min was the main factor affecting the growth of ring density of Masson’s Pine.YT was the main factor affecting the ring density of Koelreuteria paniculata Laxm,YT_max was the main factor affecting the ring density of Eucommia ulmoides Oliver,and YT and YT_min were the main factors affecting the ring density of Platanus acerifolia paniculata.5.The correlation between the tree ring width（RD,ED,LD）and ring density（RW,EW,LW）of the six tree species with the monthly meteorological factors(YT,YT_min,YT_max,YP,YRH,YS)showed that:Under the condition of sufficient water in Nanjing,temperature is the most important factor affecting the growth of growth rings,and a variety of tree species have a high response relationship with the temperature factor of C3.