Control of bracken and the restoration of heathland. II. Regeneration of the heathland community.

Published online
06 Jun 1992
Content type
Journal article
Journal title
Journal of Applied Ecology
DOI
10.2307/2404362

Author(s)
Marrs, R. H. & Lowday, J. E.

Publication language
English
Location
UK

Abstract

In trials in the Breckland region (Suffolk/Norfolk border), UK in 1978-88 on Calluna vulgaris heathland and grass (dominated by Festuca ovina) heathland sites, bracken (Pteridium aquilinum) was not treated or was cut once or twice/year from 1978-84, was sprayed with 4.4 kg asulam/ha in 1978 with or without cutting once/year in 1978-84, or was given 4.4 kg asulam in 1978 and 1979. The bracken control was implemented with or without sowing 20 000 C. vulgaris seeds/m2 at the C. vulgaris site and with or without sowing a mixture of Holcus lanatus, Festuca spp. (mainly F. ovina), Lotus corniculatus and Rumex acetosella (at 5000, 10 000, 600 and 4400 seeds/m2, respectively). Bracken control was either continued from 1985-88 or was discontinued allowing bracken recovery. On the grass heath, 13 species were recorded in the 10 years but F. ovina (sown) and Deschampsia flexuosa (colonized naturally) were dominant. After 10 years, D. flexuosa was co-dominant on many plots. On the Calluna heath, 13 vascular and three bryophyte species were found. The sown species Calluna was found mainly on seeded plots, especially where the bracken was cut. Agrostis capillaris, Dicranum scoparium and Galium saxatile were most abundant on plots where the bracken was cut twice yearly. Other species appeared independent of treatment, reflecting low abundance, ubiquitous distributions, or clumped distributions. Carex arenaria and Calamagrostis epigejos invaded in large patches where cover of other heath species was negligible. Most of the species colonizing the restored areas had higher Ellenberg nitrogen-indicator values than the dominant heathland species, indicating that soil fertility may be too high for successful heathland restoration. The results are discussed in relation to practical conservation management and vegetation dynamics.<new para>ADDITIONAL ABSTRACT:<new para>The effectiveness of a range of bracken [Pteridium aquilinum] control and restoration treatments (cutting, spraying with 4.4 kg/ha asulam and seed sowing) on a Calluna and grass heath (Cavenham and Weeting Heaths, resp., in the UK) were studied over 10 years. In the grass heath, 13 species were recorded during the study period, although, in most plots, 2 species were dominant: Festuca ovina which was sown, and Deschampsia flexuosa which colonized naturally. F. ovina rapidly colonized the sown plots, but D. flexuosa appeared 5 years later. After 10 years, D. flexuosa was co-dominant on many plots. On the Calluna heath, 13 vascular and 3 bryophyte species were found. The sown species Calluna [vulgaris] was found mainly on sown plots, especially where the bracken was cut. Agrostis capillaris, Dicranum scoparium and Galium saxatile were most abundant on plots where the bracken was cut twice yearly. Other species appeared independent of treatment, reflecting low abundance, and ubiquitous distributions or clumped distributions. Two clonal species, Carex arenaria and Calamagrostis epigejos, invaded in large patches where cover of other heath species was negligible. Most of the species colonizing the restored areas had higher Ellenberg nitrogen-indicator values than the dominant heathland species, indicating that soil fertility may be too high for successful heathland restoration. The results are discussed in relation to practical conservation management and vegetation dynamics.

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