Tropical treelines and global change in the high Andes

Dr. Alexandra Ponette-González and colleagues were awarded a National Geographic Society grant to conduct research on treeline and global change in northern Peru.

At high elevations across the tropical Andes, montane forests grade into alpine grasslands, overlapping at their edges to create a unique transition zone referred to as treeline. Modified by humans for millennia, this vast ecotone stretches thousands of kilometers from western Venezuela to northern Argentina, yet remains virtually unexplored--cartographically and biologically. As a result, there is little evidence to indicate if, how, and at what rate the Andean tropical treeline will respond to global environmental change. Will interactions between land-use legacies and altered climate stabilize or destabilize existing boundaries between forests and grasslands?

With support from the National Geographic Society Committee for Research and Exploration and Ponette-González's NSF Minority Postdoctoral Research Fellowship, Ponette-González and her colleagues are investigating this long unresolved question in Río Abiseo National Park, Peru. The interdisciplinary research team uses methods spanning multiple spatial and temporal scales, including dendroecology, vegetation and soil analysis, and GIS mapping, to understand current and future treeline responses to reduced grazing pressure, fire exclusion, and climatic change.

Team members include researchers with expertise in geography, paleoecology, and botany from institutions in the U.S., Peru, and Argentina: Dr. Alexandra Ponette-González (UNT), Dr. Matthew Fry (UNT), Dr. Kenneth Young (UT Austin), Dr. Blanca León (UT Austin), Susana Castillo (Museo Natural de Historia, Peru), and Dr. Julieta Carilla (Universidad de Tucumán, Argentina).