Remote sensing of relative moisture status in old growth Douglas fir

One of the limiting factors affecting the growth of trees is the presence or absence of sufficient moisture. In locations where seasonal moisture deficits are frequent this can lead to substantial variations in the magnitude of tree growth. In these situations the detection of variations of canopy moisture through remote sensing techniques can improve forest mapping and management. This Letter reports on a study examining the potential of utilizing optical remotely sensed data to detect variations in canopy reflectance at a number of growth-limited sites located on southern Vancouver Island, Canada. Topographic variations coupled with rapidly drained soils and precipitation induced moisture deficits promote spatial variations in growth rates of the dominant tree species, coastal Douglas fir. Optical remotely sensed data were collected using the AVIRIS sensor and comparison of annual growth rates with reflectance data made.