Butterworts
Pinguicula spp.
Other names: P. lusitanica, P. vulgaris
Family: Lentibulariaceae
Fire effect on plant
Butterworts are likely to survive low-severity fires outside the growing season. Fires that are severe or occur during the summer may kill butterworts.
Key traits
Butterworts are insectivorous, perennial plants that cannot tolerate much shade from taller vegetation (Heslop-Harrison, 2004). In the summer Butterworts have a rosette of low-lying leaves shallowly anchored by a tuft of fine, fibrous roots. Outside the growing season, butterworts exist as a hibernaculum. Butterworts are quite tolerant of disturbance, such as freezing and drought, as hibernacula (Heslop-Harrison 2004), and so it reasonable to think they can survive low-severity fires in this form too (although this is not explicitly described in the literature in UK butterwort species). Consistent with this is the finding of mature plants, as well as seeds, of P. vulgaris in Norwegian Calluna heathlands managed by traditional heather burning in the winter/early spring (Måren & Vandvik, 2009). Fires during the growing season, that consume above-ground biomass, are likely to be much more damaging to butterworts.
Butterworts, such as P. vulgaris, are known to colonise areas rapidly after fire from a soil-stored seed bank (Måren & Vandvik,2009).
There is no specialed dispersal mechanisms in these species meaning dispersal distances are low (0.1-1m; Lososová et al, 2023).
Plant response to fire
Species in the Pinguicula genus are described as fire dependent (Folkerts, 1977), with frequent, low-severity winter fires needed to maintain suitable habitat. Fire reduces competition and shading from other species, and stimulates growth in butterworts. Fire suppression is considered a threat to Pinguicula species, via competitive and shading effects as well as fuel build up leading to the increased possibility of severe fires (Folkerts, 1977).
Timing of life history
Perennial species. Seeds likely produced from second growing season. Flowering May to July.
Conservation status
None.
References
Folkerts, G. W. 1977. Endangered and threatened carnivorous plants of North America. Pages 301-3 13 in G. T. Prance and T. S. Elias, editors. Extinction is forever: proceedings of a symposium held at the New York Botanical Garden, Bronx, N.Y. [Empirical evidence; Academic literature]
Heslop-Harrison, Y. (2004), Pinguicula L.. Journal of Ecology, 92: 1071-1118 [Empirical evidence; Academic literature]
Lososová Z., Axmanová I., Chytrý M., Midolo G., Abdulhak S., Karger D.N., Renaud J., Van Es J., Vittoz P. & Thuiller W. 2023. Seed dispersal distance classes and dispersal modes for the European flora. Global Ecology and Biogeography, 32(9), 1485–1494 [Empirical evidence; Academic literature]
Måren, I.E. and Vandvik, V. (2009), Fire and regeneration: the role of seed banks in the dynamics of northern heathlands. Journal of Vegetation Science, 20: 871-888 [Empirical evidence; Academic literature]