Common hemp-nettle
Galeopsis tetrahit
Family: Lamiaceae
Fire effect on plant
Fire kills common hemp-nettle.
Key traits
Common Hemp-nettle is a shade-intolerant, annual species that is pioneer of disturbed habitats (Delarze et al, 1992). It generates a seed stock in the soil which germinates quickly after a fire due to increased light levels, and possibly the availability of nutrients and disappearance of physico-chemical inhibitors of germination (Muller, Hanawalt & Macpherson, 1968). Seed are dispersed by wind and by flowing water. Estimates of buried seed survival in soil vary greatly from transient (less than one year) to long-term persistent (at least five years) (Thompson et al, 1997). At least some seed is almost certainly long-persistent (Roberts, 1986).
Plant response to fire
Abundance of common Hemp-nettle will likely increase after fire (Delarze et al, 1992) due to a flush of seedling establishment, before a decline driven by increasing competition and shading from perennial species.
Timing of life history
Annual species. Seeds produced within one growing season. Flowering July to September.
Conservation status
None.
References
Delarze, R., Caldelari, D., & Hainard, P. (1992). Effects of Fire on Forest Dynamics in Southern Switzerland. Journal of Vegetation Science, 3(1), 55–60 [Empirical evidence; Academic literature]
Muller, C. H., Hanawalt, R. B. & Macpherson, J. K. 1968. Allelopathic control of herb growth in the fire cycle of California chaparral. Bull. Torrey Bot.Club 95: 225-23 [Empirical evidence; Academic literature]
Roberts, H.A. 1986 Seed persistence in soil and seasonal emergence in plant species from different habitats. Journal of Applied Ecology 23: 639-656. [Empirical evidence; Academic literature]