Field data for satellite validation and forest structure modeling in a pure and sparse forest of Picea glehnii in northern Hokkaido

摘要

To validate and to improve ecological products obtained from satellites, such as a leaf area index (LAI), above-ground biomass (AGB), and a fraction of photosynthetically active radiation (fAPAR), in-situ accurate data are indispensable. They must be not a single point-data but an areal data representing the satellite footprint. Their accuracy needs to be much higher than the required accuracy for the satellite products. The quantitative assessment of their error is necessary for evaluating the satellite products' error from the discrepancy between the satellite products and the in-situ data. However, such data had not been available. In particular, there had been few data of LAI in a sparse evergreen needle-leaved forest, because of difficulty of accuracy control of in-situ observation in such a forest. To overcome the difficulty and to obtain the representative LAI, we made an allometric equation to estimate the leaf mass of Picea glehnii in northern Hokkaido. We report the allometric equations of leaf mass and AGB of P. glehnii, its leaf mass per area (LMA), its leaf life span, its leaf distribution, its crown shapes, its wood specific gravity, and tree locations. We also report LAI, AGB, and fAPAR within the 500 m x 500 m area, which is the footprint scale of the Global Change Observation Mission-Climate satellite, in a pure and sparse forest of P. glehnii in northern Hokkaido. These precise data are useful for validation of other satellite data, especially with higher spatial resolution, and forest structure modeling.