A system for identifying forest stands within an area of interest that are exhibiting abnormal growth determines a relationship between vegetation index (VI) values determined from a first and a second image of the area of interest. From the relationship, an expected or predicted VI value for each forest stand is determined and compared with the actual VI value computed for the forest stand from the first image. Those forest stands with a difference between the actual and predicted VI values that exceed a threshold are identified as exhibiting abnormal growth.