Biological Flora of the British Isles: Pteridium aquilinum (L.) Kuhn

Abstract

Summary1 This account reviews information on all aspects of the biology of bracken Pteridium (mainly aquilinum ssp. aquilinum) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, reproductive characters, herbivores and disease, history, and conservation. 2 Pteridium is a complex genus comprising a number of species, subspecies and varieties. The treatment here is based on a recent revision that incorporates both morphological and molecular data, and is related to its geographical distribution. 3 Pteridium is thought to be a woodland genus, but it can grow in the open. It is cosmopolitan and occurs on all continents except Antarctica. It responds to human disturbance and is often found in open spaces after forest clearance and cultivation. In some situations it can be a troublesome weed, causing problems for land managers. Moreover, its abundance and distribution in Britain are predicted to increase as a result of global climate change. 4 Pteridium aquilinum ssp. aquilinum, the most common taxon in the British Isles, occurs in many plant communities, and it is apparently limited by frost and waterlogging. Its abundance has probably increased in the relatively recent past as a result of changing land management, and this increase impinges on plant communities with a high conservation interest. The changed land management reflects changing use of agricultural land and also a reduction in the use of Pteridium as a resource. Accordingly, in many places Pteridium is viewed as a weed and management is needed to control it and restore more desirable vegetation. These management techniques are summarized.

Interference of Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) on the establishment of rainforest trees

“…It has been evidenced that the dense understorey layer formed by bracken also increases their impact on succession by decreasing the amount of seeds reaching the soil surface and by increasing shading (Pakeman and Marrs, 1992;Marrs and Watt, 2006). This is also supported by the work of Royo and Carson (2006), who argued that the dense understorey layer in forests is one of the causes of impact on the floristic composition rather than some allelopathic effect.…”

“…For woodland to develop in such a community it requires some form of disturbance leading P. aquilinum to diminish (Marrs and Watt, 2006). In Brazil, we suggest that succession does not take its natural course in the Atlantic Forest without an appropriate management of bracken, for example.…”

“…Pteridium has been described as a typical aggressive inflammable pioneer species, occurring in burnt or deforested sites (Alonso-Amelot and Rodulfo-Baechler, 1996;Humphey and Swaine, 1997;Snow and Marrs, 1997). Moreover, Pteridium produces what may be allelopathic compounds affecting the establishment and growth of other plant species (Gliessman and Muller, 1978;den Ouden, 2000;Gliessman, 1976apud den Ouden, 2000Marrs and Watt, 2006).…”

Demographic vulnerability of the clonal and endangered meadow thistle

“…Clonal plants with runners that successfully spread under later-successional vegetation stages [e.g., Brachypodium pinnatum (L.) Beauv. (de Kroon and Bobbink 1997) or Pteridium aquilinum (L.) Kuhn (Marrs and Watt 2006)] combine their clonality with biomass retention and with intact connections between ramets to continuously support new shoots, which C. dissectum does not.…”

Growth and morphology of three forest understorey species (Calluna vulgaris, Molinia caerulea and Pteridium aquilinum) according to light availability

“…Studies of forest ecosystems have already shown the negative impact of these three species on tree seedling establishment and growth (see e.g. Dolling, 1996;Norberg et al, 2001;Gaudio et al, 2010) and their life cycle, reproduction and resource requirements have been empirically described (for reviews, see Gimingham, 1960;Taylor et al, 2001;Marrs and Watt, 2006). They are considered light-demanding species, with Ellenberg lightrequirement indices of 6, 7 and 8 (on a scale of 9) for P. aquilinum, M. caerulea and C. vulgaris respectively (Ellenberg et al, 1992), and tolerant to acid to highly acid poor soils, and to some extent to waterlogging, which explains their broad distribution area in temperate and boreal forests.…”