Correlation between maximum latewood density of annual tree rings and NDVI based estimates of forest productivity

In boreal conifers, maximum latewood density (MXD) of annual rings varies in response to warm-season temperatures. Vegetation productivity can be estimated using the Normalized-Difference Vegetation Index (NDVI) calculated from satellite sensor data. Ground measurements related to productivity are required in order to evaluate these estimates. MXD from three boreal sites was compared with estimates of net primary productivity (NPP) for 1982-1990 produced by the CASA (Carnegie-Ames-Stanford-Approach) model from FASIR (Fourier adjustments, solar zenith angle correction, interpolation at high latitudes, and reconstruction of tropical values) NDVI. All three density series correlated significantly with the CASA estimates, suggesting that in boreal conifers MXD may be an appropriate index for productivity or canopy growth in regions where productivity is strongly temperature-related.