• Main Authors: Erik A. Hobbie, Stephen A. Macko, Herman H. Shugart
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1998
• Subjects: Glacier Bay; glacier; Alaska
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.453.1358; http://eco.ibcas.ac.cn/group/lingh/siep/pdf/StaleIsotopesyueduwenxian/Hobbieetal1999(405-415).pdf

Abstract Nitrogen cycling in forest soils has been in-tensively studied for many years because nitrogen is often the limiting nutrient for forest growth. Complex interactions between soil, microbes, and plants and the consequent inability to correlate d15N changes with biologic processes have limited the use of natural abundances of nitrogen isotopes to study nitrogen (N) dynamics. During an investigation of N dynamics along the 250-year-old successional sequence in Glacier Bay, Alaska, United States, we observed several puzzling isotopic patterns, including a consistent decline in d15N of the late successional dominant Picea at older sites, a lack of agreement between mineral N d15N and foliar d15N, and high isotopic signatures for mycorrhizal fungi. In order to understand the mechanisms creating these