Prescribed fire alters foliar stoichiometry and nutrient resorption in the understorey of a subtropical eucalypt forest.

Background and aims: Changes to soil nutrient concentrations following vegetation fire may affect biogeochemical cycling and foliar stoichiometry. Phosphorus (P)-limited plant communities are widespread and may be particularly sensitive to fire, but have received relatively little research attention in this context. Methods: We measured soil nutrient concentrations, foliar carbon (C), nitrogen (N) and P stoichiometry of understorey plants in a recently, frequently burned eucalyptus forest area in south-east Queensland, Australia, and compared these properties to an adjacent unburned area. Results: Surface soils in the area subjected to relatively recent, frequent prescribed burning had higher P concentrations than those in the adjacent unburned area, although this did not include the 'available' forms of P. All plant species had high foliar N:P ratios, regardless of fire history, consistent with widespread P-limitation. Some species had lower foliar N:P ratios in the burned area, indicating interspecific variation in nutrient requirements and burning responses. The nutrient resorption proficiencies of a grasstree ( Xanthorrhoea johnsonii Lee) were lower in the burned area, suggesting that the nutrient cycling of this species was made less conservative by burning. Conclusions: The stoichiometric patterns observed in the responses of plants to prescribed burning highlight the significance of fire in this P-impoverished plant community, and suggest the potential value of stoichiometric approaches in fire ecology. [ABSTRACT FROM AUTHOR]