Determining Critical Loads of Nitrogen Deposition in the Pacific Northwest


Principal investigators: Jasmine Saros, Rick Graw (USFS)

Bottom of Dorothy Lake sediment core

Project Summary

Paleolimnological studies in the Pacific Northwest have suggested possible acidification effects of nitrogen (N) and sulfur (S) deposition on alpine lakes in this region, but have been unable to generate a critical load at which these effects occur. In this study, we conducted a series of microcosm experiments in two sub-alpine lakes situated in the Cascade Mountain range in an effort to define critical loads of N to this region. We are also analyzing sedimentary diatom profiles from the two study lakes to assess whether diatom communities in these lakes have already responded to atmospheric deposition.


Jasmine, Natalie, and Marcus profiling Cora Lake under Mt. Rainier


Avalanche that was cleared just before research at Dorothy Lake began

On the hike to Cora Lake