[Reconstruction of July NDVI over 172 years based on tree-ring width of Larix chinensis in Taibai Mountain Nature Reserve, China.]

We used the correlation analysis of Larix chinensis tree-ring width chronologies, meteorological data as well as regional NDVI data to reconstruct the NDVI sequence variation of the north and south aspects of Taibai Mountain Nature Reserve in the recent 172 years. The results showed that the NDVI variation of Taibai Mountain Nature Reserve was consistent with plant growth dyna-mics. Hydrothermal condition in growing season was the dominant factor controlling NDVI changes. Tree-ring width was significantly positively correlated with NDVI in growing season. The strongest correlation occurred in July. Thus, we used the long time series of tree ring width index in July to reconstruct the regional historical period variation of NDVI sequence. The results demonstrated that historical changes of July NDVI sequence existed five dense periods and five sparse periods. Further analysis indicated that these periods corresponded with the climate change trends and drought events. The reconstructed July NDVI sequence of both northern and southern slopes of Taibai Mountain Nature Reserve highlighted the existence of quasi periodic variation of 60 years.