© 2000 Heron Publishing—Victoria, Canada
Leaf optical properties in Venezuelan cloud forest trees
Lourens Poorter (1, 2), R. Kwant (1), R. Hernández (3), E. Medina (3) and M. J. A. Werger (1)
1. Department of Plant Ecology, Utrecht University, P.O. Box 800.84, 3508 TB Utrecht, The Netherlands / 2. Department of Silviculture and Forest Ecology, Wageningen University, P.O. Box 342, 6700 AH Wageningen, The Netherlands (Lourens.Poorter@BTBO.BOSB.WAU.NL) / 3. Centro de Ecología y Ciencias Ambientales, Instituto Venezolano de Investigaciones Cientificas, Aptdo 21827, Caracas 1020
A, Venezuela / Received March 3, 1999
Summary
Leaf optical properties and related leaf characteristics were compared for thirteen cloud forest tree species differing in
successional status. Sun leaves were sampled for the eight pioneer species and sun and shade leaves were sampled for the five
climax species. Sun leaves had a slightly higher absorptance than shade leaves, although differences were small. Sun leaves
had a higher leaf mass per unit area (LMA) and a lower chlorophyll concentration per unit leaf mass, resulting in similar
chlorophyll concentrations per unit leaf area and hence similar light harvesting capacities as shade leaves. However, shade
leaves realized a higher efficiency of absorptance per unit leaf biomass than sun leaves. There were few differences in leaf
characteristics of sun leaves between the climax and pioneer species. Absorptance values of cloud forest species were comparable
with values reported for rain forest and more seasonal forest species. Intraspecific variation in leaf absorptance was largely
the result of variation in LMA, whereas interspecific variation in leaf absorptance was largely a result of variation in chlorophyll
concentration per unit leaf area.
Keywords:
carotenoids, chlorophyll, climax, cloud forest, leaf absorptance, light, pioneer species.
