FOREST FLOOR AND SOIL NUTRIENT STATUS UNDER NORWAY SPRUCE AND RED PINE IN A PLANTATION IN SOUTHERN QUEBEC

The influence of 40 years of red pine and Norway spruce growth on fore st floor and soil nutrient status was examined in a well-replicated se ries of plantation blocks established on abandoned agricultural land. Concentrations of N, P, K and Ca, and mass of organic matter and all n utrients in the forest floor were higher under spruce than under pine. In the mineral soil, concentrations of exchangeable K and Ca were hig her under spruce whereas Mg, extractable P and mineralizable N did not differ between the species. Forest floor pH was higher under spruce b ut mineral soil pH did not differ between the species. The soil charac teristics reflected litter chemistry of the two species. Relative to p ine, spruce foliage litter was consistently higher in nutrient concent ration and had lower acidity and higher ash bases. The results are inc onsistent with the reputation of Norway spruce as a species that stron gly acidifies soils, an observation that may be the result of elevated levels of Ca and K in our soils relative to those in other studies wh ere acidification has been observed. This research demonstrates that s oil fertility can be altered significantly by tree species effects ove r the period of a single rotation.