Earlier Springs are Causing Reduced Nitrogen Availability in North American Eastern Deciduous Forests
Elmore AJ, Nelson DM, Craine JM. 2016. Earlier Springs are Causing Reduced Nitrogen Availability in North American Eastern Deciduous Forests. Nature Plants. (16133)
ABSTRACT: There is wide agreement that anthropogenic climate warming has influenced the phenology of forests during the late twentieth and early twenty-first centuries1,2. Longer growing seasons can lead to increased photosynthesis and productivity3, which would represent a negative feedback to rising CO2 and consequently warming4,5. Alternatively, increased demand for soil resources because of a longer photosynthetically active period in conjunction with other global change factors might exacerbate resource limitation6,7, restricting forest productivity response to a longer growing season8,9. In this case, increased springtime productivity has the potential to increase plant nitrogen limitation by increasing plant demand for nitrogen more than nitrogen supplies, or increasing early-season ecosystem nitrogen losses10,11. Here we show that for 222 trees representing three species in eastern North America earlier spring phenology during the past 30 years has caused declines in nitrogen availability to trees by increasing demand for nitrogen relative to supply. The observed decline in nitrogen availability is not associated with reduced wood production, suggesting that other environmental changes such as increased atmospheric CO2 and water availability are likely to have overwhelmed reduced nitrogen availability. Given current trajectories of environmental changes, nitrogen limitation is likely to continue to increase for these forests, possibly further limiting carbon sequestration potential.
- Type
- Journal Article
- Authors
- Elmore, Andrew; Nelson, David; Craine, Joseph
- Units
- CATO , GRSM , HAFE , PRWI
- Keywords
- APHN, Appalachian Highlands Network, Biogeochemistry, CATO, Catoctin Mountain Park, climate change, Great Smoky Mountains National Park, GRSM, GRSM-01165, HAFE, Harpers Ferry National Historical Park, National Capital Region, NCR, nitrogen, Phenology, Plant physiology, Prince William Forest Park, PRWI, remote sensing, SER, Southeast Region