GOTZ SCHROTH is with the International Institute for Tropical Agriculture in Cameroon. GUSTAVO A.B. DA FONSECA is with Conservation International, USA. CELIA HARVEY is professor at the Centro Agronomico de Investigacion y Ensenanza in Costa Rica. CLAUDE GASCON is with Conservation International, USA. HERALDO L. VASCONCELOS is professor at the Federal University of Uberlandia in Manaus, Brazil. ANNE-MARIE N. IZAC is at the Centre de Cooperation Internationale en Recherche Agronomique pour le Developpement (CIRAD) in France.