We note with great sadness the passing of Alexander (Sandy) Mather on Tuesday, November 14, 2006, aged 63 years, Professor, Department of Geography and Environment, University of Aberdeen. Sandy passed away one day after the publication in PNAS of our joint paper on “Returning forests analyzed with the forest identity.†Our article in PNAS is a memorial to Sandy’s work. We first learned of Sandy while writing our papers about encroachment of farming on forests. His concept of the Forest Transition inspired us. Whenever anyone writes forest transition, they remember Sandy, pictured here leading a group in the Costa Rican forest. His passing coincides with the high-profile validation of his work over many years.
