Abstract: The correlation between the monthly, seasonal and yearly mean NDVIs of forest vegetations and corresponding water/thermal conditions (precipitation and temperature) in Northeast China from 1982 to 2003 were analyzed. Results showed that, temperature was the primary climatic factor affecting the NDVIs. The mean NDVIs of various forest vegetations had significant correlations (P<0.01) with the temperature and precipitation in spring and autumn, and the correlation coefficient with temperature was higher than that with precipitation. For cool-temperate needleleaf forest, its NDVI had significant correlation (P<0.01) with the temperature and precipitation of growing season, the correlation between NDVI and precipitation was higher than that with temperature but was adverse for the whole year. The time lag partial correlation between NDVI of cool-temperate needleleaf forest and precipitation is higher in April, with a correlation coefficient of -0.385. For temperate needleleaf and broadleaf mixed forest, the time lag partial correlation of its NDVI with temperature was higher in April-July，with a correlation coefficient of 0.581，0.490，-0.266 and -0.297, respectively. For warm-temperature deciduous broadleaf forest, the time lag partial correlation between its NDVI and temperature was higher in April, with a correlation coefficient of 0.571, while the coefficient between NDVI and precipitation was higher in July with a correlation coefficient of -0.367. During growth period, the effects of water/thermal conditions (precipitation and temperature) on forest vegetation NDVI were lagged significantly.

Key words: Tibet, Beijing, Wheat, Planting in the different location, Quality variation