Research from Radboud University shows that peatlands are vital for carbon storage and combating climate change, but are highly vulnerable to drought. Increases in biodiversity have produced little improvement in drought resilience, highlighting the need for new strategies and political intervention to protect these important ecosystems.
Peatlands are being affected more by drought than previously expected, raising concerns as they play a vital role in combating climate change. Long-term drought greatly reduces peat's ability to absorb more carbon dioxide (CO2). Furthermore, enhancing biodiversity will do little to improve peat’s drought resistance. Scientists from Radboud University report these findings in a recent study published in Proceedings of the Royal Society B.
Peat is a huge carbon sink: it can store more carbon dioxide per square meter than any other ecosystem in the world. Peatlands in the Netherlands, as well as in Scandinavia and the Baltic countries, therefore play an important role in combating climate change. However, peat is under increasing pressure and is extremely sensitive to dry summers caused by climate change. This is what researchers from the Radboud Institute of Biological and Environmental Sciences concluded.
"In our laboratory, under controlled conditions, we first ensured that the peat chunks were fully moistened over a long period of time," explains lead author Bjorn Roebruck. "We then slowly dried the peat. Half of them were subjected to mild drought, with the water level being about five centimeters lower than the peat itself. The other half was subjected to extreme drought conditions; in this case, the water level was 20 centimeters lower than the peat. This is equivalent to three weeks without rain - something that has also become increasingly common in the Netherlands in recent years."
These experiments show that peat subjected to mild drought can still sequester a certain amount of carbon. Robroek: However, under extreme drought conditions, peat can barely absorb more carbon. In the event of prolonged drought, peat may even release carbon in turn.
Of course, drought doesn't just affect peatlands. Dry summers also make other ecosystems more vulnerable. However, in the case of grasslands, we now have solutions to the problems caused by drought. Increasing the biodiversity of such ecosystems (by planting more diverse plants), such as future dike projects, can keep ecosystems healthy and resilient.
However, Roebke believes that in the case of peatlands, increasing biodiversity in this way will have little effect on drought resistance. The different moss we tested in our peat experiments did little to combat drought. This does not mean that biodiversity is not important for peat: for example, it contributes to carbon storage. But when it comes to fighting drought, a different approach is needed.
There are some small things consumers can do to protect peat. For example, buy peat-free potting substrate and compost. Ultimately, though, this is primarily a question that needs to be addressed at a political level. In the past, buffer zones along rivers often consisted of peatland, but today much of it is grassland used for agriculture. These areas are frequently mowed and plowed, so they retain little water. As a result, water from these floodplains drains into rivers more quickly, causing flooding.
Switching to natural management methods will take time and money, but will have huge benefits in the future. Peatlands, even lowland peat areas, will retain more water and therefore provide better protection. You can compare this to a sponge that gradually releases water back to the surface. In these locations, peat is also the most efficient option for storing carbon.
Compiled source: ScitechDaily