Effects of prescribed burning on soil inorganic Nitrogen, foliar chemistry, and pitch pine (Pinus rigida Mill.) seedling growth in the New Jersey Pinelands

Fire disturbances impact most terrestrial ecosystems throughout the world, and can have significant impacts on the cycling of nitrogen (N), a nutrient essential for life. Prescribed burning is regularly employed as a management practice to reduce hazardous fuels and risk of wildfires in the New Jersey Pinelands (NJPL), a fire-adapted ecosystem in central and south New Jersey. My research sought to quantify the role vegetation communities play in nitrogen retention after a fire disturbance. In a field study, I found that prescribed burning significantly increased resin-available inorganic N in burned plots. Increasing resin-available ammonium correlated negatively with understory foliar C:N, suggesting that the understory may be an important sink for N released from a fire disturbance. A greenhouse study was performed to assess how burned litter affected pitch pine (Pinus rigida Mill.) growth and foliar chemistry, and no significant effect of burned litter was observed. Overall, these results demonstrate that prescribed burns can significantly increase soil inorganic N availability to plants and that the understory community of the NJPL may be an important sink for available N after a prescribed burn.