Average tree regrowth time of CONUS from 1985 to 2017

We developed a 30-m spatial resolution forest regrowth time map for CONUS over 1985?2017. This map is the first attempt, as far as we know, to quantify tree regrowth rate at a national extent in the United States. The method used all available Landsat images to detect disturbances over forest lands and classify grass/shrub to tree class transitions on an annual basis. The average regrowth time was then calculated for each pixel that experienced tree regrowth process. The regrowth map was validated with independent reference data, showing average one-year of difference and 6-year standard deviation difference in the national tree regrowth time. The southeast is a major tree regrowth region where our map also showed higher accuracy with less than one-year average difference and 3.6 years standard deviation. The satellite-estimated regrowth time of major forest types agreed well with the reference data.