The Value column is a housekeeping column. Pixels marked with the value 1 in the "NCS_Refor column" of this raster display the extent of Reforestation as shown in Fig S1A of the following publication:

Griscom, B., Adams, J., Ellis, P., Houghton, R.A., Lomax, G., Miteva, D.A., W. H. Schlesinger, D.S., Woodbury, P., Zganjar, C., Blackman, A., Campari, J., Conant, R.T., Delgado, C., Elias, P., Hamsik, M., Kiesecker, J., Landis, E., Polasky, S., Putz, F.E., Sanderman, J., Siikamäki, J., Silvius, M., Wollenberg, L., Fargione, J., Conservancy, T.N., Nichols, M., 2017. Natural climate solutions. Proc. Natl. Acad. Sci. doi:10.1073/pnas.1710465114

Note that this map does NOT include the following non-spatial deductions:

1) The mean forest “gain” rate for 2000-2012.

2) The unmapped area of forested peatlands and mangrove forests

See "Reforestation" Section of Supplementary Material starting on p 48 for details:

https://www.pnas.org/content/pnas/suppl/2017/10/11/1710465114.DCSupplemental/pnas.1710465114.sapp.pdf