Impact of tree species on soil solutions in acidic conditions

Abstract

Capillary solutions of two acidic forest topsoils were sampled for one year. On each of the two soils there were three stands (Norway spruce, Douglas fir, Hardwood). Capillary solutions were extracted using the centrifugation method. Soil moisture under Hardwood stands was higher than under coniferous stands. Soil solutions under the coniferous tree species were more acidic and more concentrated in SO4-2 and Na+ than under Hardwoods, showing that coniferous tree species intercept atmospheric depositions more efficiently than hardwood tree species do. Soil solutions under hardwood stands were more concentrated in K+, Alt, Si and Fe3+ than those under coniferous stands. On the least desaturated site, soil solutions under the hardwood stand were less concentrated in NO3--N and C than under the coniferous stands. The amount of rainfall significantly influenced results by diluting soil solutions. When the amount of rainfall was high, there were little difference between tree species.