Abstract

Tropical montane cloud forests (TMCF) belong to the most species-rich terrestrial habitats and are characterized by a prolific and extremely specialised epiphyte flora. Compared to vascular epiphytes such as orchids and bromeliads, epiphytic bryophytes (mosses and liverworts) dominate the canopies of TMCF . Being poikilohydric organisms, water input from rain and fog represents the most limiting factor for photosynthesis and productivity of these cryptogams. Epiphytic bryophytes can therefore serve as sensitive indicators of climatic changes in TMCF biomes. This project is set out to examine bryophyte diversity, abundance and ecophysiology along an environmental gradient in southeastern Peru. The aim is to undertake an integrated study which analyses canopy profiles of bryophyte species richness, biomass and water storage along an altitudinal transect from the high Andes to the Amazon lowland forest. Stable isotopes 13C and 18O are used as tracers of plant-environment interactions. Given that the cloud base and precipitation inputs may shift in response to global warming, we hypothesize that the cryptogamic flora in TMCF could provide sensitive markers of changing climatic conditions.