Effect of Nitrogen Availability on Nitrogen Cycling in a Douglas-Fir Stand

Abstract

Short-term nitrogen cycling in a Douglas-fir stand was assessed for uptake and return to the forest floor. The five treatments included separate applications of nitrogen and carbohydrate, the latter being used to widen the forest floor C/N ratio and reduce N availability. Effects of nitrogen applications included increased N uptake and needle biomass and decreased forest floor weight compared to the control, while the carbohydrate treatment caused a reduction in N uptake, increased internal redistribution, and reduced needle biomass. FOREST SCI. 23:307-316.