Environmental quality effects and the ecological context of a rainforest canopy bromeliad fauna
McCracken, Shawn F.
Canopy strata of tropical forests are one of the remaining unexplored biotic frontiers. New access techniques enabling us to reach the canopy have facilitated an increased investigation on the ecology of forest canopies and their function in tropical ecosystems. As the interface between the terrestrial environment and atmosphere, the canopy and its inhabitants are integral to ecosystem function and maintenance. Epiphytes, particularly tank bromeliads, provide microhabitat for a high diversity of fauna and flora in tropical forest canopies and are considered a “keystone resource”. Anthropogenic perturbations are rapidly altering the landscape of the Ecuadorian Amazon and along with it the species diversity, forest dynamics, and ecosystem functions. Aechmea zebrina is a large tank bromeliad typically found in the high canopy of the upper western Amazon Basin in Columbia and Ecuador. As part of this study I have identified a diverse amphibian community inhabiting these phytotelmata, yet their ecological role in forest canopies remains primarily unknown. I investigated the symbiotic relationship of A. zebrina bromeliads and their inhabitants, ecological factors driving this relationship, microclimate moderation by A. zebrina supporting faunal diversity, vertical distribution of the amphibian chytrid fungus Batrachochytrium dendrobatidis, and the influence of anthropogenic forest disturbance on the anuran inhabitants of A. zebrina. My research has resulted in a successful protocol for sampling the fauna of high canopy bromeliads. It has contributed to the identification and description of new bromeliad-inhabiting anuran species, along with accounts of reproductive ecology and behavior. Ecological characteristics of A. zebrina bromeliads were quantified and effects of microclimate moderation identified as playing a significant role in A. zebrina providing a viable microhabitat in the harsh canopy environment. The first occurrence of B. dendrobatidis in lowland Amazonian rainforests and canopy-inhabiting anurans was discovered across a vertical gradient from the forest floor to the upper canopy. Lastly, low-level anthropogenic forest disturbance along an isolated oil road was found to negatively impact the abundance, occurrence, and diversity of anuran inhabitants in A. zebrina. These data provide science-based support to promote social responsibility and conservation efforts throughout Amazonia.
Ecology, Oil road, Generalized Linear Mixed Model, Pristimantis, Batrachochytrium dendrobatidis, Anthropogenic disturbance, Amphibian, Anura, Herpetofauna, Rainforest, Neotropical, Canopy, Bromeliad, Aechmea zebrina, Amazon
McCracken, S. F. (2012). <i>Environmental quality effects and the ecological context of a rainforest canopy bromeliad fauna</i> (Unpublished dissertation). Texas State University-San Marcos, San Marcos, Texas.