Climate change alters stoichiometry of phosphorus and nitrogen in a semiarid grassland
Article first published online: 25 SEP 2012
© 2012 The Authors. New Phytologist © 2012 New Phytologist Trust
Volume 196, Issue 3, pages 807–815, November 2012
How to Cite
Dijkstra, F. A., Pendall, E., Morgan, J. A., Blumenthal, D. M., Carrillo, Y., LeCain, D. R., Follett, R. F. and Williams, D. G. (2012), Climate change alters stoichiometry of phosphorus and nitrogen in a semiarid grassland. New Phytologist, 196: 807–815. doi: 10.1111/j.1469-8137.2012.04349.x
- Issue published online: 9 OCT 2012
- Article first published online: 25 SEP 2012
- Manuscript Accepted: 22 AUG 2012
- Manuscript Received: 23 JUL 2012
- US Department of Agriculture (USDA)-Agricultural Research Service Climate Change
- Soils & Emissions Program
- the US National Science Foundation. Grant Number: DEB# 1021559
- US Department of Energy's Office of Science
- Australian Research Council. Grant Number: FT100100779
- elevated carbon dioxide;
- N : P stoichiometry;
- nutrient availability;
- PHACE ;
- soil moisture;
- Nitrogen (N) and phosphorus (P) are essential nutrients for primary producers and decomposers in terrestrial ecosystems. Although climate change affects terrestrial N cycling with important feedbacks to plant productivity and carbon sequestration, the impacts of climate change on the relative availability of N with respect to P remain highly uncertain.
- In a semiarid grassland in Wyoming, USA, we studied the effects of atmospheric CO2 enrichment (to 600 ppmv) and warming (1.5/3.0°C above ambient temperature during the day/night) on plant, microbial and available soil pools of N and P.
- Elevated CO2 increased P availability to plants and microbes relative to that of N, whereas warming reduced P availability relative to N. Across years and treatments, plant N : P ratios varied between 5 and 18 and were inversely related to soil moisture.
- Our results indicate that soil moisture is important in controlling P supply from inorganic sources, causing reduced P relative to N availability during dry periods. Both wetter soil conditions under elevated CO2 and drier conditions with warming can further alter N : P. Although warming may alleviate N constraints under elevated CO2, warming and drought can exacerbate P constraints on plant growth and microbial activity in this semiarid grassland.