Mechanisms of nitrogen deposition effects on temperate forest lichens and trees

• DOI: 10.1002/ecs2.1717
• Publication Date: 2017-03-28T23:12:42Z
• Authors: Therese S. Carter; Christopher M. Clark; Mark E. Fenn; Sarah Jovan; Steven S. Perakis; Jennifer Riddell; Paul G. Schaberg; Tara L. Greaver; Meredith G. Hastings
• Keywords: Temperate rainforest; Temperate forest; Deposition; Global Change

Abstract We review the mechanisms of deleterious nitrogen (N) deposition impacts on temperate forests, with a particular focus trees and lichens. Elevated anthropogenic N to forests has varied effects individual organisms depending characteristics both inputs (form, timing, amount) (ecology, physiology) involved. Improved mechanistic knowledge these can aid in developing robust predictions how respond either increases or decreases deposition. Rising levels affect micro‐ macroscopic ways from physiological responses at cellular, tissue, organism influencing species entire communities ecosystems. A synthesis processes forms basis for overarching themes this paper, which focuses different biological organization forests. For lichens, direct are relatively well known organismal, community levels, though interactions other stressors merit further research. trees, better understood as an acidifying agent than nutrient; cases, reflect short time scales indirect mediated through long‐term soil belowground changes. There many gaps fundamental use cycling ecosystems, we highlight most critical understanding potential include affects specific metabolic pathways is metabolized. onto forest canopies, sensitivity tree mycorrhizal symbionts N, influence properties, reversibility acidification plants soils. Continued study response interact one another, dimensions global change, remains essential predicting ongoing changes lichen populations across North American