Effects of considering greenhouse gas consequences on fertilizer use in loblolly pine plantations.

Fertilizer use, widely practiced in forest plantation management to stimulate tree growth, contributes to greenhouse gas (GHG) emissions. We explore how accounting for GHG consequences affects optimal fertilizer application rates of commercial forest plantations. A generic model that maximizes the equivalent annual net benefit of timber production and GHG balance is developed and applied to loblolly pine (Pinus taeda L.) plantations in the southern United States. We find that fertilizer use still is a viable practice for managing loblolly pine plantations in the region although fertilizer application rate should be reduced when GHG consequences are valued. A greater reduction in fertilizer application rate is recommended where wood is used for paper production because life cycle GHG emissions of paper products are much higher than those of solid wood or bioenergy products. A higher fertilizer rate should be applied when forest residues are used for the production of bioenergy that offsets GHG emissions from consuming fossil fuels.