The importance of cool burning

Yorkshire Dales Moorland Group

There is a cold breeze, the skies are clear and the moorland vegetation is dry enough for legal cool burning. The moss and peat beneath the heather is wet and cold, reptiles and amphibians are hibernating deep in the peaty litter and there are no birds breeding on the moorland vista as yet. These are the ideal conditions for trained, professional moorland gamekeepers to carry out rotational burning.

This practice breaks up the vegetation into micro habitats, creates optimised conditions for grouse and rare waders and importantly reduces the build up of combustible material and fuel loads.

Research into heather management using strip burning has ignited (forgive the pun) the topic of prescribed burning as a legitimate management tool. The 20 year study by Prof. Andreas Heinemeyer of York University has, at the midway point, discovered that burning is a valuable tool that will play a vital role in reaching carbon uptake ambitions set by government. His research has revealed that burned plots expectedly release carbon at the time of combustion but within 5 years the re-growing heather absorbs more atmospheric carbon than uncut, unburned, abandoned plots. Furthermore, heather that was just cut and not burned released large quantities of the green house gas methane as it rotted.

Professor Heinemeyer’s findings also showed that where heather was left to grow rank this contributed to reductions in the water table as the plant transpired water from its mature structure. This is not good for carbon uptake as peat (a form of stored carbon) forms best in wet conditions where sphagnum only semi decomposes to build peat that locks in the carbon from the air.

Additional research has revealed that sphagnum mosses (peat builders) are up to five times more prevailant on burned plots as light reaches the exposed ground surface. Since heather moorland is a fire evolved land type it is no surprise to moor keepers that research is now proving what they've always known. Not only does controlled cool burning help increase peat formation by increasing sphagnum it also reduces wildfire risk - a fact stated by all leading global fire ecologists.

You would think that with scientists and fire experts stating that controlled burns are better for the environment, the penny would drop with policy makers. Moor managers and keepers are still waiting for that time to happen. Ignoring these repeated messages is not only risking millions of tonnes of carbon stores its literally playing with fire!