003420000a2200109000450024500760000065000230007665000270009965000240012604100130015010000240016377300450018710aObservations on biological aspects of productivity of forest ecosystems14aBosques tropicales14aCambios vegetacionales14aEspecies forestales0 aInglés1 aRamakrishnan, P. S.1 tGlimpses of Ecology3252q193-199d1982?