Insects, Infestations, and Nutrient Fluxes

Abstract

Forest ecosystems are characterized by a high temporal and spatial variability in the vertical transfer of energy and matter within the canopy and the soil, or, more generally within the above- and below-ground compartments of ecosystems (McDowell and Likens 1988). In temperate forests, the principle flow path of organic matter and associated nutrients from the canopy to the ground is provided by litterfall, amounting to annual fluxes of carbon between 900 and 2,600 kg ha −1 year −1 and 20–55 kg ha −1 year −1 for nitrogen (Michalzik et al. 2001). Secondly, organic matter and nutrients are returned to the soil by fluctuating rates of throughfall deposition achieving annual fluxes per hectare between 40 and 160 kg DOC (dissolved organic carbon), 1.2–11.5 kg DON (dissolved organic nitrogen), 0.49–10.4 kg NO 3 -N, and 0.28–12.7 kg NH 4 -N (Michalzik et al. 2001).