My master’s program project employs the use of remotely sensed and field data to characterize forest structure on the North Rim of Grand Canyon National Park.  The motivation for this study is the need for a forest structure monitoring protocol for the North Rim.  I am testing the value of small footprint lidar for its ability to provide the needed forest structure information. Because lidar is currently expensive, I will be determining the utility of Landsat data when used in combination with lidar, where the lidar data are used to inform the Landsat analysis, and thus provide a more comprehensive training dataset.  Several variables will be mapped, including tree density, height, canopy cover, basal area and biomass.

Fire catalyzes ecosystem change and drives terrestrial and atmospheric carbon dynamics from local to global scales.  In western North America, fire has recently recovered its dominant disturbance role.  Since 2002, large fires have burned more than 65,000 hectares (160,000 acres) across diverse forest gradients in the Eastern Cascade Range of Oregon.  Because of key feedbacks with anthropogenic climate change, it is increasingly important to quantify and understand fire’s impacts on terrestrial ecosystems.

The current study focuses on four large fires that burned approximately 35% of the Metolius Watershed (~115,000 hectares) in 2002 and 2003, generating a landscape mosaic of burn severity.  Specific objectives are to: (a) quantify post-fire distributions of live and dead biomass pools; (b) evaluate remotely-sensed trajectories of aboveground biomass and associated fire impacts; (c) model landscape carbon balance before and after recent fires.  Methods include field surveys, data assimilation, remote sensing (Landsat), and ecosystem modeling (Biome-BGC process model).  To facilitate analysis of post-fire interactions across three landscape gradients (forest type, burn severity, and pre-fire biomass), 48 inventory plots were established using a stratified random factorial design and sampled in the summer of 2007.

Preliminary findings indicate that: (a) the fires yielded complex mortality patterns and associated shifts in carbon balance; (b) natural recovery is strong, with patchy but generally abundant conifer regeneration and diverse shrub and herbaceous communities; (c) the fires tended to kill fire-sensitive species such as Grand Fir, while fire-adapted Ponderosa Pine and Douglas-Fir survived, potentially moving the system toward historic conditions.  Ongoing analyses and results from this study will advance scientific understanding of pre- and post-fire ecosystems and help inform management across a biologically and socially important landscape.

Research interests: Satellite remote sensing of forest structure and ecosystem function, land cover and land-use change from local to global scales, mapping peatlands for global carbon research.