Advancing the Study of Soil Change through the Northeastern Soil Monitoring Cooperative.

We have long known that soils are continually changed through natural processes and human activities, but the recognition that these changes can be better understood through repeated measurement of soil properties is a more recent development.    Measurements of soil change over periods ranging from a century to less than a decade can now be found in the literature.  Opportunities for measuring soil change are expanding through the use of archived soils collected in past decades for various studies of acid deposition and forest ecosystems.  To promote the study of soil change through the development and oversight of consistent methodologies, the Northeastern Soil Monitoring Cooperative was formed in March 2007.  Planning is underway for the fourth annual workshop.  Information on the structure and activities of the Cooperative will be presented.  As an example of methodological and interpretive issues addressed by the Cooperative, soil data will be presented from northeastern red spruce stands that were sampled in 1992-93 and resampled in 2003-2004.  Detailed evaluation was done to verify consistency in sampling approaches and chemical analyses, and to evaluate possible storage effects.  Several statistically significant differences in soil chemistry were identified, including changes in organic carbon concentrations and exchangeable Al concentrations.  These differences provided insight into processes that may be responding to changes in atmospheric deposition and climate on a decadal time scale-results that indicate value in the continued monitoring of these soils.