Species-specific trajectories of nitrogen isotopes in Indiana hardwood forests, USA

Citations of this article
Mendeley users who have this article in their library.


Humans have drastically altered the global nitrogen (N) cycle, and these alterations have begun to affect a variety of ecosystems. In North America, N deposition rates are highest in the central US, yet there are few studies that examine whether N availability has been increasing to different tree species in the forests of the region. To determine the species-specific trajectories of N availability in secondary temperate forests experiencing high N deposition, we measured the N concentrations and composition of stable N isotopes in wood of four tree species from six hardwood forest remnants in northern Indiana, USA. Annual nitrogen deposition rates averaged 5.8 kg ha -1 from 2000 to 2008 in this region. On average, wood δ 15N values in Quercus alba have been increasing steadily over the past 100 years. In contrast, wood δ 15N values have been declining in three other hardwood species - Acer saccharum, Carya ovata, and Fagus grandifolia - over the same time period. The species-specific trends suggest a change in the partitioning of ammonium and nitrate among species, due to an increase in nitrification rates over time. With no apparent net change in wood δ 15N over the past century at the stand level, there is currently little evidence for consistent trends in stand-level N availability over time in the Indiana forests. © Author(s) 2012.




McLauchlan, K. K., & Craine, J. M. (2012). Species-specific trajectories of nitrogen isotopes in Indiana hardwood forests, USA. Biogeosciences, 9(2), 867–874. https://doi.org/10.5194/bg-9-867-2012

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free