Richness of cultivable endophytic fungi along an altitudinal gradient in wet forests of Costa Rica

Abstract We collected various plant species along an altitudinal gradient ranging from 400 to 2900 m in tropical wet forests of Costa Rica, isolated the associated endophytic fungi, and performed bioinformatic analyses to determine whether changes in altitude are related to changes in their richness and community structure. We showed that the richness of endophytic fungi varied along the altitudinal gradient, being higher in the lowest stratum and decreasing as elevation increases. Each stratum presented a particular composition and diversity of endophytes, although the whole population was characterized by the presence of a few dominant and apparently ubiquitous species, coexisting with a number of less abundant species that presented a more limited host range. These results have important implications for better understanding the role of altitude on the distribution and composition of endophytic fungal populations in tropical forests, but also for maximizing the number and diversity of endophytic isolates in bioprospecting campaigns.