Revista Chilena de Historia Natural 75 (4): 757-765, 2002
RESEARCH ARTICLE
Effects of the cushion plant Oreopolus glacialis (Rubiaceae) on species richness
and diversity in a high-Andean plant community of central Chile
ERNESTO I. BADANO, MARCO A. MOLINA-MONTENEGRO, CONSTANZA QUIROZ & LOHENGRIN A.
Cushion plants growing in high mountain habitats can modify the microclimate within their
canopy generating microhabitats more favorable for the recruitment of other plant species, acting as nurse plants. Although several
studies have shown that species richness is higher within cushions than outside them, no attempts have been made in order to
assess the effect of cushions on other community aspects such as total and individual abundance, diversity and evenness. In this
study we analyzed the effect of Oreopolus glacialis –a cushion plant from the South American Andes- on the species
richness, total and individual abundance, diversity and evenness of a plant community located in a high mountain environment at 1,900
m of altitude in central Chile. Species richness and abundance were determined both within and outside O. glacialis
cushions. Results showed that, per area, species richness and individual abundance were higher within cushions. In contrast,
diversity and evenness within O. glacialis cushions were lower than outside. This apparent incongruence was caused by
some species being highly dominant within cushions. Analyses of the frequency and abundance of each species showed that not all
the species were affected in the same way by the cushions, with only four species growing more frequently within cushions. This
suggests that nurse effect of O. glacialis is a species-specific phenomenon.
facilitation, nurse effect,
positive interactions, cushion plants, Andes
