Physical Sciences and Mathematics Commons^™

Soil Processes Drive Seasonal Variation In Retention Of 15N Tracers In A Deciduous Forest Catchment, Christine L. Goodale, Guinevere Fredriksen, Marissa S. Weiss, Carmody K. Mccalley, Jed P. Sparks, Steven A. Thomas

School of Natural Resources: Faculty Publications

Seasonal patterns of stream nitrate concentration have long been interpreted as

demonstrating the central role of plant uptake in regulating stream nitrogen loss from forested

catchments. Soil processes are rarely considered as important drivers of these patterns. We

examined seasonal variation in N retention in a deciduous forest using three whole-ecosystem

¹⁵N tracer additions: in late April (post-snowmelt, pre-leaf-out), late July (mid-growingseason),

and late October (end of leaf-fall). We expected that plant ¹⁵N uptake would peak in

late spring and midsummer, that immobilization in surface litter and soil would peak the

following autumn leaf-fall, and that leaching losses …