Herbivory in epiphytic bromeliads, orchids and ferns in a Mexican montane forest

Abstract

Herbivory is important in tropical woody plants, but the few data available suggest that rates of herbivory are mostly low in epiphytes. We quantified herbivory at the community level in five bromeliad, three orchid and five fern species of a Mexican humid montane forest. Leaf area loss was <1.5% in bromeliads and orchids, but much higher (7–20%) in ferns. Damage was positively correlated with leaf nitrogen content but not with leaf life span. In contrast to low leaf damage, many bromeliads were infested by curculionid larvae feeding on the meristematic tissue at the ramet base, and we estimate that this accounts for 18 and 31% of ramet and shoot death of large individuals of Tillandsia punctulata and T. deppeana, respectively. Herbivory in flowers, capsules or inflorescence stalks reduced fecundity by c. 14–18% in three of the five bromeliads and by 90% in the orchid Lycaste aromatica, but had little effect on the other species. These data show that even if the leaf area consumed is indeed low in epiphytic orchids and bromeliads, the less conspicuous damage done to reproductive organs and meristematic tissue can have a strong effect on fecundity and survival.