The Ecosystem Ecology Laboratory
In collaboration with Stan Wullschleger and Charles Garten we used a basic ecosystem model to test the hypothesis that the intra-specific variation in leaf and root litter chemistry and decomposition rates among hybrid poplar genotypes has large and sustained impacts on soil carbon sequestration and ultimately alters ecosystem trajectories.
The role of intra-specific variation in leaf and root litter chemistry among hybrid poplar genotypes in soil C sequestration
The response of terrestrial ecosystems to climatic changes is likely constrained by extant traits of the ecosystem such as N availability. Using a large-scale field experiment (Free-Air CO2 Enrichment Experiment – FACE) that manipulates CO2 levels in a forest, Colleen Iversen led a project to examine if previously observed changes in carbon allocation to fine roots is due to N limitation and what an increase in soil C from root inputs might mean for long-term C storage and N cycling in forests.
Colleen on NPR: ME 02.22.08 ORNL FACE Site ck.mp3
The role of nutrient availability in limiting forest response to global change
In collaboration with Richard Norby and Jake Weltzin, we established a multi-factor climatic change experiment in an old-field to test the relative importance of direct and interactive effects of climatic drivers on ecosystem function.
Click here to see a list of publications resulting from this project
Old-field Community, Climate and Atmospheric Manipulation (OCCAM)
Belowground respiration consists of root, bacterial, and fungal respiration. Each of these components is likely to respond to perturbation differently, yet ecologists have no way of adequately teasing them apart from bulk soil respiration measurements. In collaboration with Chris Schadt we used qRTPCR to assay portions of the ecosystem transcriptome that may be indicative of autotrophic and heterotrophic respiratory activity.
Scaling across levels of biological organization to better understand how climatic change may alter ecosystem function
