title: [Acumen function in leaves and its vertical distribution in a tropical rain forest of Costa Rica].
abstract: Water retention on the leaf surface can be maladaptive to the plant because it increases the colonization of epiphylls and interferes with the physiologic processes of the leaf, diminishing the photosynthetic capacity. To test if leaf driptips facilitate leaf drying after rainfall in a tropical rain forest of Costa Rica, we (1) experimentally measured the capacity to retain water on leaf surfaces of 30 plant species before and after driptip removal, and (2) analyzed the development of driptips along forest strata. We expected leaf driptips to be less developed in the upper strata due to the environmental conditions of the canopy (i.e., high solar radiation, strong winds and low relative humidity), which favor the natural drying of leaves. The presence of driptips increased 100% the water run off capacity of leaves in all the analyzed species. Also, the development of leaf driptips was smaller in canopy species than in understory species. Additionally, they became less developed in canopy species as trees increased in height. These results support the hypothesis that the adaptive role of driptips is to facilitate the drying of leaf surfaces.
authors.affiliation: Lab. Ecotono, Depto. de Ecología, CRUB, Unidad Postal Universidad del Comahue, (8400) Bariloche, Argentina. alefarji@yahoo.com
authors.forename: Alejandro G
authors.initials: AG
authors.lastname: Farji-Brener
authors.forename: Oscar
authors.initials: O
authors.lastname: Valverde
authors.forename: Leonardo
authors.initials: L
authors.lastname: Paolini
authors.forename: María
authors.initials: M
authors.lastname: de los Angeles La Torre
authors.forename: Estela
authors.initials: E
authors.lastname: Quintero
authors.forename: Elisa
authors.initials: E
authors.lastname: Bonaccorso
authors.forename: Luisa
authors.initials: L
authors.lastname: Arnedo
authors.forename: Richard
authors.initials: R
authors.lastname: Villalobos
mesh_terms: D003364:Costa Rica; D018515:Plant Leaves / Q000145:classification / Q000378:metabolism / Q000502:physiology*; D011891:Rain; D014197:Trees; D014867:Water
chemical_list: D014867:Water