The Effects Of Climate Warming On The Growth Characteristics Of Tetracentron Sinense Oliv.

In this paper,we use the ARSTAN method to establish the standard chronology,difference chronology and autoregressive chronology of the Teracentron sinense Olive,and combine the research sites 1983-2013 meteorological elements(monthly average precipitation,monthly average temperature,monthly extreme temperature)A significant correlation analysis was performed to investigate the response of radial growth of Teracentron sinense Olive to climatic factors.At the same time,the anomaly analysis of the meteorological factors in the narrowest and widest annual years of the test results was carried out to test the test results;Exploring the photosynthesis difference of young Teracentron sinense Olive and Teracentron sinense Olive in the reproductive stage in different elevation by comparison of leaf phenotypic analysis,photosynthetic parameters,net photosynthetic rate,intercellular C02 concentration,stomatal conductance,transpiration rate and light response curves of young Teracentron sinense Olive and Teracentron sinense Olive in the reproductive stage at three elevation.Simulating temperature reduction with elevation increases,"spatial sequence instead of time successional sequence" indirectly explore the effects of climate warming on the morphology and physiological processes of Teracentron sinense Olive.The main findings are as follows:(1)Growth response of Teracentron sinense Olive to climatic factorsBoth temperature and precipitation have an effect on the radial growth of the Teracentron sinense Olive.In terms of temperature,the radial growth of the Teracentron sinense Olive was significantly positively correlated with the monthly average temperature in July of that year and the extreme maximum temperature in March and July of that year(P<0.05),and was significantly negatively correlated with the extreme minimum temperature in November of that year(P<0.01).In terms of precipitation,the radial growth of the Teracentron sinense Olive was significantly negatively correlated with the monthly average precipitation in September of the previous year and April of that year(P<0.01).The temperature in the pre-season and mid-growth seasons is the main factor affecting the radial growth of the Teracentron sinense Olive.The results of the anomaly analysis of meteorological factors with the narrowest(1983)and widest(2008)annual rings are consistent with the above conclusions.(2)Photosynthetic characteristics of Teracentron sinense Olive in different elevation Regions.The maximum net photosynthetic rate of Teracentron sinense Olive increased with altitude,and the light compensation point increased first and then decreased with the elevation.The light saturation point increased with the elevation.The youngTeracentron sinense Olive increased with altitude.Gradually increase,the leaf length gradually increases,and the leaf dry weight gradually decreases.This is the adaptive response of the leaf shape of the Teracentron sinense Olive to the low light environment in high altitude areas.There was no significant difference in the maximum net photosynthetic rate of Teracentron sinense Olive with altitude at the reproductive stage.The light saturation point and light compensation point increased first and then decreased with altitude.The phenotype of Teracentron sinense Olive leaves in the reproductive stage increased with altitude.The area gradually increased,the leaf length gradually increased,and the leaf dry weight gradually decreased,which was consistent with the sapling stage of the Teracentron sinense Olive,but the change range was not as large as that of the Teracentron sinense Olive.Combined with the above conclusions,it can be concluded that temperature and precipitation have effects on the radial growth of Teracentron sinense Olive in Dafengding Nature Reserve under historical climate conditions.The monthly mean temperature in July of that year,the maximum temperature in March and July of that year are the important factors affecting the growth of Teracentron sinense Olive in the study area,and the monthly average precipitation in September last year and April of that year is the main limiting factor for the radial growth of Teracentron sinense Olive In the future,the influence of climate warming on younger trees is greater than that of young trees,and the natural regeneration of T.sinense would be affected by climate warming..