Fire frequency increased under past warmer conditions in an eastern Canadian peatland

Why did we do this project?

Peatlands are a type of wetland ecosystem where remains of plant materials build up over thousands of years to form carbon-rich peat in waterlogged conditions.

Peat soils play important role in regulating climate, as they store approximately one third of global soil carbon but occupy less than 5% of the Earth’s surface.

Conserving and restoring peatlands are therefore important steps towards natural climate solutions.

Read this open access paper on the FACETS website.

There are uncertainties, however, in the capacity of peatlands to continue to store soil carbon under future climate change.

One key uncertainty in predicting the ability of peatlands to store carbon is changes in future fire patterns.

Longer periods of summer drought and higher water deficits in certain regions means that more peatlands will dry out and be vulnerable to surface burning and carbon loss.

Therefore, it is important to identify which peatlands are more vulnerable to create effective fire management plans.

One way to predict how these ecosystems will respond to changes in fire patterns is to look at how a site responded to changes in the past, as warmer conditions in Earth’s history can act as an analog.

How did we do it?

We used a peat corer to collect soil samples extending to depths of 1–2 m below the ground surface to track changes over time. We sieved the samples to locate charcoal fragments preserved in these peat cores and used radiocarbon dating to determine that the lowermost peat in these cores is more than 7000 years old.

We used these methods to investigate how changes in past climate impacted how frequently a peatland site was burned.

Read the paper — Using Holocene paleo-fire records to estimate carbon stock vulnerabilities in Hudson Bay Lowlands peatlands by M.A. Davies, J.W. McLaughlin, M.S. Packalen, and S.A. Finkelstein.