Die Bodenkultur - Journal for Land Management, Food and Environment

R. Jandl and E. Herzberger:

Is soil chemistry an indicator of tree nutrition and stand productivity?


We investigated if the foliar nutrient levels of trees, a proxy for tree nutrition, are closely related to the nutrient content of forest soils. In addition we investigated if the Yield Class, a proxy for the general growing conditions of a stand, is related to two common soil chemical indicators, the C:N ratio and the base saturation, We used a subset of the data from the Austrian Forest Monitoring System (WBS). Our analysis was restricted to sites on non-calcareous parent rock, where stands are dominated by Norway spruce (Picea abies). Overall, the relation between tree nutrition, Yield Class, and soil chemical data was weak. Obviously spruce is able to extract the required sufficient amounts of nutrients at a wide range of soil chemical conditions, Spruce efficiently scavenges nutrients over a wide range of soil chemical conditions. Even on poor sites high foliar nutrient levels can be maintained, because nutrients taken up are kept in a tight biogeochemical cycle. We conclude that soil chemical conditions are weak predictors of the Yield Class. Other factors, such as climate and water relations, seem to exert a larger influence on the nutrition and growth rate of spruce forests.

Keywords: tree nutrition, forest soil chemistry, nutrient content of needles, Yield Class, Norway spruce, Austrian Forest Monitoring System (WBS).