Transandean Distributions of Bromeliaceae in Ecuador

Abstract

The distributions of members of the tropical plant family Bromeliaceae with their soil—nutrient independence are especially linked to microclimate and are valuable indicators of microclimatic regimes. Meteorological records show that the annual rainfall on the eastern slopes of the Ecuadorian Andes is higher and more evenly distributed than on the western slopes, which receive very little precipitation during several months of the year. Seventeen of the 249 Ecuadorian species of Bromeliaceae are known from collection records to be distributed on both the eastern and western slopes of the Andean Cordillera. On the eastern slopes, individuals of these species have been consistently collected at lower altitudes than on the western slopes. The more even distribution of precipitation throughout the year and the smaller range in relative humidity on the eastern slopes is apparently responsible for the strikingly lower elevations of the species' distributions on most of the eastern slopes.