(1) Independent of NDVI source, the NDVI–LAI relation-ship varies both inter and intraannually. Three pheno-logical stages (leaf production, leaf-constant, and leaf
senescence) had different NDVI–LAI relationships.
There were strong linear relationships during the leaf
production period and leaf senescence period. On the
other hand, there was no clear relationship between
NDVI and LAI during the leaf constant period. This is
mainly due to the saturation of NDVI above certain
LAI values.