PROBLEM TO BE SOLVED: To provide a method for evaluating healthiness of plants at higher accuracy, using spectral reflection characteristic of trees. SOLUTION: This method for evaluating healthiness of each tree comprises collecting leaves from trees of a subject kind of investigation, measuring spectral reflection data with a multipurpose spectral reflectometer or spectral reflectometer Field Spec from right above the trees, and investigating from collected soil in each investigation point, soil characteristics of volume water content, macropore ratio, pore void ratio, gap ratio, coefficient of permeability, effective depth of soil and final infiltration rate to relate to the spectral reflection data. Furthermore, the method comprises making a database through relating nutrition data in the collected leaves to spectral reflection characteristics, performing regression analysis by multivariate analysis, making a healthiness database through relating leaf spectral characteristics to healthiness of trees by every tree kind, soil characteristics and nourishment in leaves with vegetation environment data, reading spectral characteristic of the trees from satellite images of high resolution, and referring the healthiness database with the soil characteristics of trees as a subject to be investigated and the nourishment data in leaves. COPYRIGHT: (C)2007,JPO&INPIT
