Successional changes in nitrogen availability as a potential factor contributing to spruce declines in boreal North America

Examines the hypothesis that depression of soil N availability by litter from black and white spruce (Picea mariana, P. glauca), which is low in N and high in recalcitrant compounds, may lead directly to spruce decline or predispose the forest to dieback from other factors. Model also shows that if litter of red spruce (P. rubens) has a similar effect on the N cycle, then the effect of acid deposition on red spruce decline must be considered in light of this intrinsic property of spruce ecosystems. -from Authors