PARENT SESSION
Organized Oral Session 6: Development of landscape heterogeneity at multiple scales in wetlands
Organizer(s): B Warner and A van der Valk
Monday, August 8, 8:00 AM - 11:30 AM, Meeting Room 516 A, Level 5, Palais des congrès de Montréal

Peatlands in the arid landscapes of the central Andes.

Warner, Barry¹, Squeo, Francisco², Aravena, Ramon^*,1, Maldonato, Antonio^*,2, ¹ University of Waterloo, Waterloo, Ontario, Canada² Departamento de Biologia, Casilla 599, La Serena, Chile

ABSTRACT- Bofedales are alpine peatlands found in the arid Puna grasslands and Southern Andean steppe ecozones of the central Andes. Members of the Juncaceae, most common species being Oxycloe andina and Patosia clandestine, are the community dominants and primary peat-formers. The bofedales are fed by groundwater, streams, snowmelt, and rain making them freshwater and mildly saline. Radiocarbon ages indicate that some bofedales are 1,000-2,000 years old confirming a recent origin, while others may be as old as 9,000 years. Rates of peat and carbon accumulation are the highest known for peatlands in the world. The occurrence of these exceptional ecosystems in this water-stressed landscape is directly linked to climate. Global Climate Models predict a 25% decrease in moisture over the next 50 years in the central Andes. Measurements of plant biomass production from year to year show changes in response to water availability and length of growing season are directly controlled by El Nino Southern Oscillations (ENSO) phenomena. We can expect that primary productivity in bofedales, and hence capacity to form and accumulate peat, will decrease after several successive El Nina (dry) years. A series of successive El Nina years would contribute to bofedales degradation and a major decline in extent and health of these delicate and unique ecosystems. This paper discusses the linkages between past, present, and future climate in shaping the occurrence and character of bofedales in the southern part of their range in northern Chile.©