Regional droughts have led to extensive mortality and range shifts in the keystone species, quaking aspen (Populus tremuloides). We are investigating the genetic and ecophysiological basis of this mortality, and are using remote sensing methods to better predict future mortality. This work is based in southwestern Colorado.

Climate change is driving increasingly hot and dry conditions in many parts of the world. We are investigating how plant water and carbon use strategy may change in extreme environments, via work in deserts and seasonally dry tropical forests.

We work to scale up plant functional trait measurements to performance, demographic parameters, and geographic distributions. We use a combination of ecophysiological and energy budget modeling approaches coupled to modern coexistence theory. Fieldwork includes monitoring and trait measurement campaigns throughout the world.

One long-term research site in Colorado (Mt. Baldy) has focused on detailed measurements of alpine plant community dynamics for the past six years.

Biotic interactions play a key ecological role in shaping the compositions and dynamics of communities. We investigate trait-based approaches for predicting these interactions, as well as observational approaches for detecting them. We also develop theory for controlling and manipulating interaction networks and ultimately community structure.

Plants have leaves characterized by an intricate network of veins. These venation networks may play a key role in mediating plant performance via tradeoffs inherent to the construction of resource supply and distribution networks, and are a key example for understanding the general properties of other transport networks, e.g. urban systems. We are interested in understanding how the geometry of these networks reflects their evolutionary history and ecological context, to better use network traits to predict species functioning and distribution. We are especially interested in variation in reticulation (looping) within these networks. We develop conceptual and software approaches for quantifying these networks as well as carry out broad-scale trait measurements across environments and clades. This work is supported by the National Science Foundation’s Rules of Life program and the Smithsonian Institution.

Hutchinson’s n-dimensional hypervolume concept underlies many areas of modern ecology and evolutionary biology. We examine the potential and the limitations of this approach for modeling species’ distributions, quantifying functional diversity, and understanding community dynamics.

Past climate change and past human uses of landscapes may have a strong legacy on contemporary biodiversity patterns. Understanding these effects will be key to making robust predictions about future biodiversity dynamics. We develop concepts for understanding disequilibrium in communities and regions based on these effects, and also carry out comparative empirical studies using large eco-informatics resources and various Holocene and Anthropocene data sources.

Humans may have shifted ‘natural’ baselines in many regions due to the dispersal of species for food usage. We are investigating the scope and impact of these influences in order to better understand the non-climate factors driving plant diversity in the past and in the future.

Urban systems share some important similarities to ecological systems in terms of their composition and spatiotemporal dynamics. We apply ecological concepts and use informatics methods to better understand constraints on urban development and diversity, and to better predict how future urbanization processes can be shaped to support better outcomes for humans and nature.