Wildfire Training and Mitigation

Wildfire risks are rising in the Great Fen. Learn from Natural England Reserve Manager, Tristan Colaco, how the reserves teams are preparing.

Spreading like wildfire

Climate change is likely to increase the chances of prolonged spells of hot and dry weather like we have experienced this summer. At a site like Holme Fen NNR, this is perhaps a cause for concern. Holme Fen was drained in the 19^th century, resulting in the site’s peat soils drying out. In hot and dry weather, the peat gets even drier - putting it at significant risk of fire. As well as representing a safety risk, fires in peat result in large releases of carbon dioxide by burning organic material that has been locked in the soil for hundreds or even thousands of years and thus causing further global warming.

Unfortunately, wildfires are already fairly frequent at Holme Fen. Most summers there are at least one or two occasions when the peat catches fire; normally caused by someone having a barbeque or a campfire. As our site is at high wildfire risk, Natural England put several of the reserve team through wildlife training this summer. We learnt more about how to safely tackle wildfires as well as getting insight into how best to assist the emergency services if a fire gets too large to be tackled by reserve staff alone. Later in the year, some of our staff will be attending further training into how we might adapt management on site to reduce the risk of fires happening in the first place.

Giving Bracken a Bruisin'

This time of year is particularly risky for wildfires. The peat soils have had the whole summer to dry out and the bracken that is found across much of the site is dying back - leaving large amounts of dry organic matter above ground. Perhaps one way to reduce the risk of fires at Holme Fen would be to try and reduce the dense bracken cover in parts of the site.

This summer we have been trying out a new management technique to achieve this at Holme Fen using a bracken bruiser. This is a roller that is dragged behind a tractor or ATV across the plants, and which damages the stems at various points. The theory is that this reduces the ability of the bracken to send photosynthetic products down to its rhizomes. Thus, over years of repeated rolling, the vigour of the bracken is reduced. Hopefully this will also allow other more delicate plants to take hold. This should not only reduce the amount of vegetative material and reduce fire risk but should simultaneously improve floristic diversity. We look forward to seeing how this novel management impacts Holme Fen.

Rolling blades on wheels over green bracken leaves — Bracken bruising - Steve Bighi

Digger on grass pathway next to water and tall reeds — Ditch slubbing - Tristan Colaco

Slubbing It

As well as trying out new management techniques like the bracken bruising, we have also been continuing our more established management at the NNRs of the Great Fen. Management of the ditches at Woodwalton Fen is particularly important due to the variety of plants and animals that make the ditches their home.

Slubbing - the removal of silt - is one key aspect of our ditch management. Slubbing ensures that ditches don’t completely silt up and dry out. We slub our ditches on rotation, some being cleared as frequently as every other year, and others left for at least seven years (though sometimes far longer!). By slubbing rotationally, hopefully we maintain ditches in a variety of different states, and thus provide suitable conditions for the greatest range of species that we can.

One of the special species that calls our ditches home is Greater Water Parsnip. This member of the carrot family is fairly large but has seen rapid declines across the country in the past 200 years and is now classified as nationally scarce. It requires fairly careful management; it doesn’t really like disturbance but requires some cutting and slubbing of the ditches it inhabits to stop them becoming scrubbed over. In order to better understand how our management impacts Greater Water Parsnip, this year we have carefully mapped the distribution on site. Hopefully this better understanding will allow us to ensure this beautiful plant continues to thrive at Woodwalton Fen.