I have diverse interests in ecology and evolution. A few aspects of my current and past research are:

Meta-Ecosystem Processes

The meta-ecosystems framework addresses the movement of organisms and material among ecosystems. Instead of considering only dispersal of organisms (as in a meta-community framework), a meta-ecosystem consists of patches (ecosystems) linked by movement of both resources and of living and dead organisms. Almost all ecosystems on earth are open to such flows, therefore considering meta-ecosystem processes is important even when the goal is to understand the dynamics of specific local ecosystems. I use the meta-ecosystem framework for much of my empirical research in specific study systems (such as watersheds, below), but also ask more general questions using data synthesis and theory:

Watershed Meta-Ecosystems

Freshwater systems have an extensive interface with the terrestrial world: river networks snake across a matrix of land. Classic work in ecosystem ecology established that a large part of the material and nutrients in freshwater food webs come from the terrestrial side of this interface. My work is interested in the fate of these terrestrial subsidies and their effects on freshwater ecosystem functioning. A central part of my approach is considering watershed-ecosystems not just as having terrestrial and aquatic components, but also as comprising linked aquatic ecosystems. That is, the configuration of both the terrestrial landscape, and of reaches and habitats within a river or stream network, is important to the quantity and distribution of resources, and their consumption by aquatic organisms. I use a combination of field surveys, experiments, and geostatistical modeling to tease apart these processes.


Dispersal is a key process in meta-communities and meta-ecosystems. While it is an important parameter in theoretical work, it is also a biologically very complex process. I am interested in inter- and infraspecific variation in dispersal, both based on organismal traits (condition-dependence) and environmental conditions and species interactions (context-dependence). I’m particularly interested in the implications of infraspecific variation in dispersal on ecosystem function. So far, my work on dispersal has been focused on mesocosm experiments.

Community Assembly and Biodiversity

One of the central questions in ecology is, why are species found where they are? I am interested in the interplay between organisms’ ability to get to an ecosystem (see above) and their ability to persist once there, interact to shape community composition and structure, and ultimately the community’s contribution to ecosystem functions. I’m especially interested in how these dynamics are modified by the structure of landscapes, e.g. through dispersal limitation, and on how communities respond to disturbance and longer-term global change. I study community ecology processes in the field with both experimental and observational approaches.

Global Change in Tundra Communities

One of our best options for understanding what effect future climate change might have on natural ecosystems comes from long term manipulations. Working with field sites which have been undergoing warming for one to two decades as part of the International Tundra Experiment (ITEX), I previously examined community composition and, to a much lesser extent, ecosystem processes. This work also contributed to the Tundra Trait Team, which pooled tundra data to ask whether responses are similar across regions, community types, and functional groups, or whether heterogeneity of these responses make it difficult to predict the sum of global change effects. While I do not have any active tundra research at the moment, I’m interested in returning in the future to work on the ecosystem function consequences of community change (or resistance to change), and possibly applying the meta-ecosystem framework in the arctic.