The Nutrient Content of the Soil and Root System of a Dry Heath Ecosystem

Nutrient budgets have been described for the above-ground components of the vegetation of a dry heath ecosystem in the south of England (Chapman 1967). In that paper the plant nutrients contained in the rooting system and in the soil were not considered. There is no need to emphasize the importance of the root system in the ecosystem but in the past it has not been so well studied or described mainly because of the practical difficulties involved. Methods of estimating root production have been discussed by Newbould (1968), and by a number of authors in the proceedings of an international symposium (U.S.S.R. Academy of Sciences 1968). Some past work on heathland and moorland has included studies of the root systems of Calluna or associated vegetation, but very little includes estimates of root biomass or the nutrient content of the root system. Brien (1950) measured the root volume of plants of Calluna on a variety of soils. Rennie (1953, 1957) and Boggie (1956) studied the distribution of Calluna roots within the soil profile. Boggie, Knight & Hunter (1958) studied the activity of roots of species including Calluna by use of radioactive phosphorus. This present paper is intended to provide preliminary estimates of the root biomass and of the amounts of plant nutrients contained within the rooting zone of a lowland heath ecosystem and to consider them in relation to the above ground vegetation and litter.