Climate change contribution to forest growth in eastern China over past two decades

Abstract

China has experienced substantial climate change during past decades. To understand the response of forests to this change, we investigated the trends in forest growth and the control mechanism behind the observed variations in the North-South Transect of Eastern China (NSTEC). Interpretations were made based on the Normalized Difference Vegetation Index (NDVI) and temperature and precipitation data from 1982 to 2006. Our results indicated that the growing season NDVI trend showed a significant linear relationship with the mean growing season temperature and precipitation trend exhibiting inconsistent or even opposite performances from the north to south of the NSTEC. Prevalent forest greening was observed in the cold and dry regions where the climate becomes warmer and drier, while forest browning appeared to dominate in the warm and humid areas where climate turns warmer and wetter. These phenomena indicated the positive effect of growing season climates on forest growth may stall under warmer and wetter conditions in the much warmer and wetter regions. Our findings showed a difference in growth trend between needle leaf forests and broadleaf forests. In the cold and dry regions, the NDVI of most needle leaf forests showed an increasing trend, but nearly half of the broadleaf forests exhibited a negative NDVI slope while the other broadleaf forests exhibited a positive NDVI slope.