Geophytoelectrical current in trees of a subtropical rainforest in Mexico

Abstract

The geophytoelectrical current of three evergreen tropical tree species is studied as an indirect measure of their relative water content. Two intermediate shade-tolerant species (Aphananthe monoica and Pleuranthodendron lindenii), distributed in the middle and upper canopy strata, and an understory shade-tolerant species (Psychotria costivenia) were examined. The annual rhythm of geophytoelectrical currents per cm of diameter (DBH) is seasonal, with the highest occurrence in the winter and summer. There is a significant association between maximum temperature, moisture in the environment, and geophytoelectrical current per cm of DBH in the three species, as shown by multiple regression analysis. This finding suggests the existence of various geophytoelectrical current patterns which differs from that reported for temperate species. © 2007 Institute of Experimental Botany, ASCR.