Oil palm (Elaeis guineensis) mapping with details : smallholder versus industrial plantations and their extent in riau, Sumatra - Descals, Adrià (Centre de Recerca Ecològica i d'Aplicacions Forestals) ; Szantoi, Zoltan (Stellenbosch University) ; Meijaard, Erik (Borneo Future) ; Sutikno, Harsono (Austindo Nusantara Jaya Tbk) ; Rindanata, Guruh (Austindo Nusantara Jaya Tbk) ; Wich, Serge (Liverpool John Moores University. School of Biological and Environmental Sciences)