Introduction

Bryophytes are closely associated with the type of substrate on which they grow. Streambanks with cliffs and rocks provide an unique mesohabitat for the colonization and growth of bryophytes.

This research focuses on bryophytes that grow on rock substrate at the streambanks in the tropical rainforest of Costa Rica.

The environmental variables considered are size of rock, river velocity, and canopy cover.

Null hypothesis: The factors river velocity, canopy cover, and size of substrate have no effect on bryophyte growth and distribution on rocks at streambanks in the tropical rainforest of Costa Rica.