Abstract
Species-related differences in needle litter nutrient concentrations and subsequent N mineralization were examined in 17-year-old stands of loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.) at a common site. Results of this common-garden study indicate that a feedback may exist between foliar litter nutrient concentration and soil N mineralization. Net N mineralization (to 30 cm) was significantly greater in loblolly pine than in slash pine stands, which was attributed to greater litter nutrient concentrations in loblolly pine. Stand volume production was also greater in loblolly pine than in slash pine and was positively correlated with N mineralization. Although lower litter nutrient concentrations may have reduced productivity of slash pine relative to loblolly pine in this study, they may serve as a mechanism to increase the relative fitness of the species by lowering the soil nutrient availability below the optimum of loblolly pine.