Response of element cycles in a tropical mountain rain forest to environmental and land-use change

北安第斯森林受到气候驱动的酸碱沉积的影响，未来将经历越来越多的N输入。基于我们在旧金山保留区的元素循环知识，我们的目标是开发研究森林对预期环境变化的可能反应的情景。我们将评估现有的数据系列，并完成基于流域的水文模型(CATFLOW)的参数化。我们将假设研究股的联合变化情景。所开发的情景将通过继续进行长期生态系统研究和养分管理实验(Numex)来验证。长期生态系统研究是在1998年建立的。11年来，收集了所有主要水和元素通量的每周记录的独特数据集。在2007年建立的跨学科Numex实验中，我们每年连续两次在原生林中按区块设计增加N、P、N+P和Ca，大约2000 m a.s.l。探讨森林对低水平养分输入的响应。在下一阶段，将进行联合15N脉冲追逐实验，以进一步探索添加N的命运。我们通过建立应用的同位素标记的完整流量预算来做出贡献。

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 catchment-based 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 >11 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. For the next phase, a joint 15N pulse chasing experiment will be conducted to further explore the fate of added N. We contribute by setting up a complete flux budget of the applied isotope label.