Contents volume 7

Abstract

Modern pollen rain from a one-hectare plot of the South Brazilian Atlantic rain forest of the reserve Volta Velha (26°04′S, 48°38′W, 9 m asl) and two secondary forests, ±50 and 7 years old, were analyzed by pollen traps. 248 identified tree, shrub and herb species (excluding epiphytes) of 50 families (Angiospermae, Gymnospermae and Pteridophyta) from the plot of the Atlantic rain forest are represented by 126 different pollen and spore types (including non-local taxa). The calculated average influx of pollen rain from the native Atlantic rain forest is 12,465 pollen grains cm−2 yr−1. The influx from the ±50 years old and from the 7 years old secondary forest is relatively low (4112 and 3667 grains cm−2 yr−1, respectively) compared to the undisturbed rain forest. The occurrence of pollen grains of herbs and fern spores is significantly higher in the secondary forests than in the undisturbed rain forest. Pollen rain in the rain forest is very variable due to local effects. Therefore, results from single terrestrial pollen traps and surface samples from tropical forests should be cautiously applied to the interpretation of fossil pollen records. They can give an incorrect impression of the vegetation and cannot be used as representative data.