X2 A6. Response of element cycles in a tropical mountain rain forest to environmental and land-use change
PI(s) for this project:
Nutrient cycles and their response to climate change in a tropical montane rain forest in the Andes of South Ecuador.
The north Andean forest is affected by climate-driven acid and base depositions and will experience increasing N input in the future. Based on our knowledge of element cycling in the Reserva Biologica San Francisco, we aim at developing scenarios of possible responses of the study forest to expected environmental change. We will evaluate the available data series and complete the parameterization of a catchmentbased hydrologic model (CATFLOW). We will assume the joint change scenarios of the Research Unit. The developed scenarios will be validated by continuing the Long-term Ecosystem Study and the Nutrient Management Experiment (NUMEX). The Long-term Ecosystem Study was established in 1998. For >15 years, a unique data set of weekly records of all major water and element fluxes has been collected. In the interdisciplinary NUMEX experiment, established in 2007, we continuously add N, P, N+P, and Ca twice per year to native forest in a block design at ca. 2000 m a.s.l. to explore the forest response to low-level nutrient input. In 2012, a 15N pulse chasing experiment was conducted on the NUMEX plots in the RBSF to further explore the fate of added N and to set up a complete flux budget of the applied isotope label.