Fig. 1

Approximate locations of vegetation change studies spanning at least 30 years. Circles show forestry plots, while squares show repeat-photography studies. These symbols are meant to show general locations only, and their size on the map is not indicative of the actual surface area studied. Arrows indicate the general trend of forest cover over the years (up or down; no arrow indicates that the study did not show a net trend in either direction). Each location is labeled with the author (and year of publication if needed to differentiate between studies), as well as the years spanned by the study. Green shading denotes areas dominated by forest or shrubland, while white indicates deserts, grasslands, agricultural lands, etc. See Appendix A for details of each study