兴安落叶松树轮宽度指数与归一化植被指数的关系研究

A Study on the Relationship between Tree Ring Width Index and NDVI of Larix gmelinii

为探究兴安落叶松树木径向生长与归一化植被指数(Normalized Difference Vegetation Index, NDVI)的关系,从而了解树木生长动态,本文运用1973-2018年塔河采样点的兴安落叶松、1982-2018年GIMMS NDVI(Global Inventory Modelling and Mapping Studies,全球植被指数变化研究)数据集与研究区的气候因子(降水量、月平均气温、月平均最低气温、月平均最高气温)进行相关分析。研究结果表明,树轮宽度指数与6月、7月、6-7月平均气温显著负相关(P<0.05),与6月、7月、6-7月平均最高气温显著负相关(P<0.05);NDVI与上年12月平均最低气温、月平均气温显著负相关(P<0.05),与5月平均气温、平均最高气温、7月平均气温显著正相关(P<0.05),NDVI与7月、8月、7-8月平均最高气温极显著正相关(P<0.01);树轮宽度指数与当年7月NDV相关关系不显著,与上年7月NDVI显著正相关。从而得出,6-7月平均最高气温是树木径向生长的主要控制因子,7-8月平均最高气温是树木冠层生长的主要控制因子,主干生长与冠层生长受控因子不同,冠层生长状况与主干生长状况不同。

To explore the relationship between radial growth and NDVI(Normalized Difference Vegetation Index)of Larix gmelinii,and to provide reference for understanding tree growth dynamics,based on Larix gmelinii at Tahe sampling point from 1973 to 2018,GIMMS(Global Inventory Modelling and Mapping Studies)NDVI data set from 1982 to 2018 and climate factors(precipitation,monthly mean temperature,monthly mean minimum temperature,monthly mean maximum temperature)was analyzed in this paper.Results showed that the tree ring width index was significantly negatively correlated with the mean temperature in June,July and June-July(P<0.05),and significantly negatively correlated with the mean maximum temperature in June,July and June-July(P<0.05).NDVI was significantly negatively correlated with the mean minimum temperature and monthly mean temperature in December last year(P<0.05),significantly positively correlated with the mean temperature in May,the mean maximum temperature in May and the mean temperature in July(P<0.05),extremely positively correlated with the mean maximum temperature in July,August and July-August(P<0.01).There was no significant correlation between tree ring width index and NDV in July of that year,but a significant positive correlation between tree ring width index and NDVI in July of last year.It can be concluded that the mean maximum temperature from June to July was the main controlling factor of tree radial growth,and the mean maximum temperature from July to August was the main controlling factor of tree canopy growth.The control factors of trunk growth and canopy growth were different,and the growth status of canopy was different from that of trunk.