Influence of forest growth on former heathland on nutrient input and its consequences for nutrition and management of heath and forest

Abstract

The low nutrient supply of heathland soils is often insufficient for the nutrient demand of growing forests and woodlands, and additional atmospheric input of nutrients is beneficial for the tree growth. On old heathland soils tree species influencing nutrient input with regard to higher amounts have competitive benefits on the early stages of succession and/or as first planted trees with consequences for both the successional development and the nutrition and management of heathland and forests. In three stages of heathland forest succession on highly acidified and nutrient poor soil, the influence of the canopies of a Calluna heathland, a pioneering birch-pine woodland, and a terminal oak-beech forest on nutrient input was investigated. Of all investigated species Scots pine has the highest interception of water and nutrients (N, K, Ca, Mg). As a consequence, the nutrient input into the pioneering birch-pine forest is the highest of the three types of ecosystems. This ability to meliorate the nutrient supply by increasing the nutrient input favours pine in the early stages of the succession. The enhanced nutrient input and accumulation within the young successional forest ecosystems involves two different succession and/or management considerations depending upon the further ecosystem development. 1. The increasing nutrient availability mitigates the negative influence of the highly acidified nutrient poor soil on the growth of oak and beech and facilitates the conversion of pine dominated woodlands and forests into forests dominated by broadleaved species. 2. For regeneration of heathland from naturally established pine woodlands and forests, deforestation have to be combined with techniques of nutrient impoverishment of the soil.