Recovery of ectomycorrhiza after 'nitrogen saturation' of a conifer forest.

Trees reduce their carbon (C) allocation to roots and mycorrhizal fungi in response to high nitrogen (N) additions, which should reduce the N retention capacity of forests. The time needed for recovery of mycorrhizas after termination of N loading remains unknown. Here, we report the long-term impact of N loading and the recovery of ectomycorrhiza after high N loading on a Pinus sylvestris forest.

N abundance of surface soils, roots and mycorrhizas in profiles of European forest soils.

N natural abundances of soil total N, roots and mycorrhizas were studied in surface soil profiles in coniferous and broadleaved forests along a transect from central to northern Europe. Under conditions of N limitation in Sweden, there was an increase in δN of soil total N of up to 9% from the uppermost horizon of the organic mor layer down to the upper 0-5 cm of the mineral soil. The δN of roots was only slightly lower than that of soil total N in the upper organic horizon, but further down roots were up to 5% depleted under such conditions.

N abundance of soils and plants along an experimentally induced forest nitrogen supply gradient.

N abundances of soils and a grass species (Deschampsia flexuosa (L.) Trin.) were analysed in a forest fertilization experiment 10 years after the last fertilization.