Fire Eases Imbalances of Nitrogen and Phosphorus in Woody Plants
Fires are widespread and can result in large nutrient losses from ecosystems simultaneous with pulses in nitrogen (N) and phosphorus (P) that can increase their availability to plants. Plant growth is frequently limited by N and P, and fire has the potential to enhance or moderate the magnitude of N and P limitation in plants with important consequences for long-term net primary productivity and global carbon cycling. We used meta-analysis to explore fire effects on N and P concentrations in aboveground plant biomass among a variety of plants and plant communities worldwide. We show that across all observations, fire enhanced N concentration in plants when N/P ratios in biomass were low, and enhanced P concentration in plants when biomass N/P ratios were high. P concentration increased particularly in woody plants. Furthermore, responses of the N/P ratio in woody plants were more flexible than in herbaceous plants so that fire eased N and P imbalances only in woody plants. Our results suggest that these changes in plant N and P in response to fire may help sustain net primary productivity and persistence of woody plants in fire-affected ecosystems worldwide.
Keywordsavailable soil nutrients disturbance meta-analysis nutrient limitation N/P stoichiometry prescribed burn slash-and-burn wildfire
We thank D. Binkley, P. Attiwill, and P. Reich for helpful comments on an earlier version of the manuscript. This research was supported by the Australian Research Council (FT100100779).
- Binkley D, Vitousek P. 1991. Soil nutrient availability. In: Pearcy R, Ehleringer J, Mooney H, Rundel P, Eds. Plant physiological ecology. The Netherlands: Springer. p 75–96.Google Scholar
- Hedges LV, Olkin I. 1985. Statistical methods for meta-analysis. Orlando: Academic Press.Google Scholar
- Jackson RB, Schenk HJ, Jobbagy EG, Canadell J, Colello GD, Dickinson RE, Field CB, Friedlingstein P, Heimann M, Hibbard K, Kicklighter DW, Kleidon A, Neilson RP, Parton WJ, Sala OE, Sykes MT. 2000. Belowground consequences of vegetation change and their treatment in models. Ecol Appl 10:470–83.CrossRefGoogle Scholar
- Randerson JT, Chen Y, Van Der Werf GR, Rogers BM, Morton DC. 2012. Global burned area and biomass burning emissions from small fires. J Geophys Res 117:G04012.Google Scholar
- Rosenberg MS, Adams DC, Gurevitch J. 1999. MetaWin: statistical software for meta-analysis. Sunderland: Sinauer Associates.Google Scholar
- Tilman D. 1988. Plant strategies and the dynamics and structure of plant communities. Princeton: Princeton University Press.Google Scholar