Studies on the conservation of lowland Calluna heaths. I. Control of birch and bracken and its effect on heath vegetation.
Single and combined treatments of 2,4,5-T were applied by paintbrush to cut Betula pendula and B. pubescens stumps and fosamine was applied by foliar spray to both Betula regrowth after cutting and Pteridium aquilinum. The effects on both the target species and the underlying heathland vegetation were assessed between 1980 and 1985. Where Betula was cut without herbicide application, recovery was rapid, overtopping the bracken between 3 and 6 years, but where cut Betula was treated with single herbicide treatments, plant numbers were reduced but individuals that survived treatment recovered almost as quickly as those untreated. Where both herbicide treatments were applied all the Betula was killed. P. aquilinum frond density was reduced in the year after spraying, but recovered rapidly almost to untreated levels in 6 years. The mature Calluna vulgaris heath present in 1980 was reduced between 1980 and 1985, especially under dense P. aquilinum, and there was very little regeneration. There was prolific establishment of both Deschampsia flexuosa and Betula seedlings, especially where control treatments were applied. The results are discussed in relation to various theories of heathland dynamics, and related where possible to practical management of lowland heaths.