Forest Phenology Dynamics and Its Responses to Meteorological Variations in Northeast China

Abstract EN

Based on time series of Moderate Resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) data (2000–2009), we extracted forest phenological variables in Northeast China using a threshold-based method, which included the start of the growing season (SOS), end of the growing season (EOS), and length of the growing season (LOS).

The spatial variation of phenological trends was analyzed using the linear regression method.

In Northeast China, SOS was delayed at the rate of <1.5 days per year.

The delay trend of EOS was well distributed in the entire region with almost the same rates.

LOS increased slightly.

The analysis of the relationship between forest phenology and meteorological variations shows that SOS was mainly affected by spring temperature, whereas SOS had a negative relationship with precipitation in the warm-temperate deciduous broadleaf forest region.

The EOS in temperate steppe region was affected by temperature and precipitation in August, whereas the others were significantly affected by temperature.

Because of the increased temperature in spring, the LOS of the temperate steppe region and temperate mixed forest region increased, and the LOS was positively correlated with the mean temperature of summer in the cool-temperate needleleaf forest region.