PREMISE OF THE STUDY: Tropical Montane Cloud Forests (TMCFs) are important ecosystems to study and preserve because of their high biodiversity and critical roles in local and regional ecosystem processes. TMCFs may be particularly affected by changes in climate because of the narrow bands of microclimate they occupy and the vulnerability of TMCF species to projected increases in cloud base heights and drought. A comprehensive understanding of the structure and function of TMCFs is lacking and difficult to attain because of variation in topography within and across TMCF sites. This causes large differences in microclimate and forest structure at both large and small scales. M ETHODS: In this study, we estimated the abundance of the entire epiphyte community in the canopy (bryophytes, herbaceous vascular plants, woody epiphytes, and canopy dead organic matter) in six sites. In each of the sites we installed a complete canopy weather station to link epiphyte abundance to a number of microclimatic parameters. KEY RESULTS: We found significant differences in epiphyte abundance across the sites; epiphyte abundance increased with elevation and leaf wetness, but decreased as vapor pressure deficit (VPD) increased. Epiphyte abundance had the strongest relationship with VPD; there were differences in VPD that could not be explained by elevation alone. CONCLUSIONS: By measuring this proxy of canopy VPD, TMCF researchers will better understand differences in microclimate and plant community composition across TMCF sites. Incorporating such information in comparative studies will allow for more meaningful comparisons across TMCFs and will further conservation and management efforts in this ecosystem.
|Number of pages||12|
|Journal||American Journal of Botany|
|State||Published - Dec 2017|
Bibliographical noteFunding Information:
We thank the members of CLOUDNET, a National Science Foundation-funded Research Coordination Network (DEB# 1146446, PIs: Heidi Asbjornsen, Thomas Giambelluca, Patrick Martin, Fredrick Scatena, and Kenneth Young), and especially Autumn Amici and Nalini Nadkarni for help in developing the epiphyte abundance protocol. The authors thank Floortje van Osch for creating Fig. 2. We thank the Curi Cancha Reserve, the Monteverde Reserve, the University of Georgia field station, and the owners of the Leiton and Buen Amigo private farms for permission to conduct this research. We also thank Todd Dawson, Kenneth Young, Nalini Nadkarni, and three anonymous reviewers for providing feedback on earlier versions of this manuscript, and acknowledge funding from Franklin and Marshall College and the National Science Foundation (PI: Gotsch, IOS Award #1556289).
© 2017 Botanical Society of America.
- Costa rica
- Elevation gradient
- Vascular epiphytes
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Plant Science