Science in Practice Portal

BLM has published several technical references to aid its field personnel in managing the 269 million arecres of public lands and resources for which it it responsible. Many of these technical references emphasize the need to collect and analyze historic information in order to better assess the potential of ecological sites.  The purpose of this technical reference is to provide resources specialists with the basic information, concepts, and procedures associated with using historical photographs to analyze changes that have occurred on specific ecological sites in relationship to possible change agents.