Areas of marked changes in NDVI and thus net primary production associated with warmer surface temperatures, increased precipitation, and/or land-use and land-cover changes from 1982 to 2005 (left) and 1982 to 1991 (right) using data with an 8 by 8-km resolution from the noted time periods. In the right figure, the increased NDVI values observed from 1982 to 1991 were due to the following: area 2 experienced warmer temperatures and a longer growing season, coupled with recovery from forest fires and logging in affected areas (the red colors); and area 5 shows the results of large-scale logging. In the left figure, NDVI increases were due to the following: area 1 experienced warmer temperatures and a longer growing season; area 3 experienced warmer temperatures and increased precipitation; and area 4 experienced widespread land-use changes, where dry land farming was replaced by center-pivot irrigation. See Figure 11 for an explanation of the land-use changes that can be observed using coarse-resolution satellite data in area 4. Credit: C.S.R. Neigh, C.J. Tucker and J.R.G. Townshend, NASA / Goddard Space Flight Center and University of Maryland (reproduced from Remote Sensing of Environment with permission from Elsevier).