Nitrogen Recovery from Decomposing Tree Leaf Tissue and Forest Humus

Abstract

AbstractRecovery of N from decomposing leaf litter of alder (Alnus rugosa [Du Rois] Spring.), dogwood (Corus florida L.), tulip poplar (Liriodendron tulipifera L.), hemlock (Tsuga canadensis [L.] Carr.), eastern redcedar (Juniperus virginiana L.), and red pine (Pinus resinosa Ait.) was studied under laboratory and greenhouse conditions. Weight loss and N deficits in decomposing tissue were more marked in hardwoods than in conifers. There was no pronounced species correlation between Ca concentration of the leaf litter and either weight loss or N deficit, but N deficit was increased in some cases by addition of CaCO3. Considerable variation in availability of N to Douglas‐fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings was observed in soil cultures where N originated from decomposing leaf tissue or from humus samples collected under the aforementioned species. Recovery of N ranged from about 60 to over 90% of the original N content.