title: Stratification of δ13C values of leaves in Amazonian rain forests.
abstract: The contribution of soil respiration to the photosynthesis of the shade flora in the Amazon forest was evaluated by measuring the δ13C values of leaves collected at different levels in two forest communities. Canopy leaves have an average δ13C of-30.5‰ in the podsol forest and-28.7‰ in the laterite forest. Leaves from plants in the lower forest strata have a significantly lower value of-35.2‰ in the podsol forest and-34.3‰ in the laterite forest.
authors.affiliation: Instituto Venezolano de Investigaciones Cientificas, Centro de Ecologia, Aptdo. 1827, Caracas, Venezuela.
authors.forename: E
authors.initials: E
authors.lastname: Medina
authors.affiliation: Physics and Engineering Laboratory, Department of Scientific and Industrial Research, Lower Hutt, New Zealand.
authors.forename: P
authors.initials: P
authors.lastname: Minchin