Sphagnum angustifolium
Sphagnum angustifolium
Fire effect on plant
Sphagnum mosses are generally top killed by moderate to high severity fires.
Sphagnum are likely to survive low severity fires, where their high moisture status prevents damage.
Key traits
Spore banking - Viability of sphagnum spores over long term storage seems to be highly variable from surviving just a few weeks through to 6 years. With Clymo and Duckett, 1986 suggesting that the half life of a Sphagnum spore bank is likely to have a half-life of 5-10 years. Field experiments with certain species suggest that S. balticum, S. lingbergii, S. fuscum and S. tenellum remain viable for at least 3 years when buried in hummock interiors within a mire (Sundberg and Rydin, 2000). Greater seed viability was maintained in S. balticum and S. tenellum (>50% of spore remaining viable after 3 years). It is noted that Sphagnum has the capacity to form a persistent spore back (defined as longevity >1 year Thompson and Grime, 1978).
Heat assisted spore germination - Heating at 40-60oC has been found to promote spore germination in S. angustifolium, S. fuscum, S. squarrosum (Yusup et al, 2022). Smoke stimulation - S. angustifolium, S. fuscum, S. squarrosum spores have been found to respond positively to combined heat and smoke treatment (Yusup et al, 2022). Ability to regrow vegetatively from unburned plant parts and fragments (Burch, 2009).
Plant response to fire
"In studies of the Hard Hill experiment (Noble et al, 2018) Sphagnum was found to be most frequent in plots that were burned on the 10 and 20 years rotations and were least frequent in plots that had not been burned since 1954. This is suggested to be because (low severity) burning may open up the canopy or increase bare ground after burning, meaning that there is less competition for sphagnum competition (Noble et al, 2018). Similarly Gimingham (1988) observed that bryophtyes in general are abundant in the pioneer stage of heather growth. Baclary-Estrup noted that the depth of the moss layer between the Pioneer and Degenerate stage of Calluna growth is actually similar. In a study of the North Yorks Moors, Burch (2009) found that the greatest number of growing tips of Sphagnum species tended to be found during the Pioneer and Building phases of heather development, and the lowest at the Mature phases.
Other research suggests that ash deposition and its high phosphorus content may enhance moss spore germination (Pouliot, et al, 2015) and as noted above several sphagnum species appear to be able to their spore dormancy broken by combined heat and smoke and indeed water and smoke treatment (Yusup et al, 2022). This may hint at the possibility of some species having evolved to cope with fire.
Some Sphagnum species appear to be able to survive heating both in terms of their vegetative growth (Noble et al, 2019) and their spore banks in soil (Yusup et al, 2015). It has been noted that the role of rotational burning in keeping fuel load down may aid sphagnum survival as it means that any fires are of lower severity which reduces heat-related damage of the moss (Noble et al, 2018; 2019 and references therein). In wet environments S. papillosum, S. capillifolium and S. austinii were found to show less than 25% damaged cells on exposure to heat of 125oC (Noble et al, 2019), they note that the temperatures reached at the level of the sphagnum bed is key in determining Sphagnum survival or damage. Here they attribute greater dwarf shrub cover prior to burning produces hotter fires which are more damaging to peatland ecosystems and sphagnum communities. Hence the ‘cooler burns’ of controlled burns have a less negative impact on Sphagnum, whereas if wildfires ensue in greater (unmanaged) heather fuel loads will have a more detrimental effect on Sphagnum communities.
Timing of history
Sexual reproduction occurring in the spring and summer.
Conservation status
Conservation action: Protected - Sphagnum balticum.
References
Burch, J (2009). The regeneration of bryophytes after the burning of dry and wet heath: a literature review and a field study conducted on the North Yorks Moors. Natural England Commission Report NECR011 [Empirical evidence; grey literature]
Clymo RS, Duckett JG (1986). Regeneration of Sphagnum. New Phytologist 102: 589–614. [Empirical evidence; Academic literature]
Noble, A., O’Reilly, J., Glaves, D.J., Crowle, A., Palmer, S.M., Holden, J. (2018) Impacts of prescribed burning on Sphagnum mosses in a long-term peatland field experiment. PLoS One, https://doi.org/10.1371/journal.pone.0206320 [Empirical evidence; Academic literature]
Noble, A., Crowle, A.,J., Glaves, D.J., Palmer, S.M., Holden, J. (2019) Fire temperatures and Sphagnum damage during prescribed burning on peatlands. Ecological Indicators, 103, 471-478. [Empirical evidence; Academic literature]
Pouliot R, Hugron S, Rochefort L, Godbout S, Palacios JH, Groeneveld E, et al. Manure derived biochar can successfully replace phosphate rock amendment in peatland restoration. Journal of Environmental Management. 2015;157:118–26. [Empirical evidence; Academic literature]
Sundberg, S., Rydin, H (2000). Experimental evidence for a persistent spore bank in Sphagnum. New Phytologist, 148, 105-116. [Empirical evidence; Academic literature]
Yusup, S., Sundberg, A., Fan, B., Sulayman, M., Bu, Z-J (2022). The response of spore germination of Sphagnum Mosses to Single and Combined Fire-Related Cues. Plants, 11, 485. [Empirical evidence; Academic literature]