Natalie Zurbriggen - Personal Homepage

Organisational unit: Landscape Dynamics Dynamic Macroecology Phone: +41 44 7392 817 Fax: +41 44 7392 215 Room: Bi HL E 28 E-Mail: Address: Swiss Federal Research Institute WSL Zürcherstrasse 111 8903 Birmensdorf

Research interests

I am interested in forest dynamics, especially how biotic processes (such as neighborhood interactions) and abiotic processes (such as disturbances) together influence the spatial patterns of tree composition and structure at multiple scales, and how these may change over time. In this respect, we can learn much from the absence of trees in certain areas, such as above alpine treelines or beyond species' ranges. I am particularly interested in how biotic and abiotic processes can be inferred from existing spatial and temporal patterns for improving (dynamic) forest modeling, and in the application of models to projecting forest dynamics in continually changing environments.

In my PhD work I focused on the following key questions:

• Which stages of a tree's life are important for limiting adult recruitment? For a tree species to move to higher altitudes with climate change, one of the earliest limiting stages is species-specific seedling survival and performance. In a field experiment at and above the current treeline I followed seedling performance of seven species over several years.
• How do limiting factors and processes, such as climate and disturbances, interact to shape the forests and treelines? This is a crucial consideration because interactions and feedbacks may affect trees near the alpine treeline differently than trees at lower elevations. I am exploring this complex interplay of forces using the dynamic and spatially-linked forest-landscape model TreeMig, with a focus on snow avalanches, and their interaction with alpine forests.
• How can feedbacks between forests and snow avalanches be represented in a dynamic and spatially explicit model? Avalanches influence forests by increasing mortality, changing species composition, and altering the spatial patterns of the treeline. Forests can also influence snow avalanches, mainly by reducing avalanche release probability, which leads to a positive feedback between them. I incorporated a dynamic and spatially explicit representation of snow avalanches into the forest-landscape model Treemig to explore several questions: How can feedback processes on different spatial and temporal scales be combined in a model? How do feedbacks interact with the changing climate? What is the range of projections for future avalanche release areas and protection forests?

Publications

Conference contributions

Projects

CCES MOUNTLAND

Co-supervised MSc thesis

• Hug D. 2011, Simulating future tree species composition in abandoned chestnut orchards in southern Switzerland. Department of Forest Ecology, Institute of Terrestrial Ecosystems, Swiss Federal Institute of Technology ETH. Main supervisors: Prof. H. Bugmann, M. Conedera, H. Lischke