carbon isotope ratio elevational gradient forest-use intensity functional traits nitrogen isotope ratio vascular epiphytes Island Biogeography Pacific Ocean naturalised species plant invasion species database Aboveground-belowground interactions Acalypha diversifolia Adenaria floribunda Aegiphila panamensis Alchornea costaricensis Alchornea latifolia Amaioua corymbosa Anacardium excelsum Andira inermis Annona spraguei Apeiba tibourbou Ardisia bartlettii Baccaris trinervis Banara guianensis Brosimum guianense Byrsonima crassifolia Byrsonima spicata Calophyllum longifolium Calycolpus warszewiczianus Casearia arborea Casearia commersoniana Casearia guianensis Casearia sylvestris Cecropia insignis Cecropia obtusifolia Cecropia peltata Cespedesia spathulata Cestrum megalophyllum Chromolaena odorata Chrysophyllum argenteum Citrus aurantium Clibadium surinamense Clidemia dentata Coccoloba manzinellensis Cochlospermum vitifolium Conostegia speciosa Conostegia xalapensis Cordia alliodora Cordia bicolor