Greenhouse gases in balance? De Sedge as a storage place

In the De Zegge Nature Reserve in Geel, the scientific department of Antwerp Zoo conducts research on greenhouse gas emissions such as carbon dioxide (CO2) and methane (CH4). “De Zegge is not only the oldest nature reserve in Flanders, but it is also a place in our country where a lot of living peat can still be found in the soil. A peat area is an ideal place – both active and passive – to store carbon dioxide.” “It is therefore essential “Conserving the area and knowing its impact on greenhouse gas emissions,” explains scientist Willem-Jan Emsens from Antwerp Zoo’s Center for Research and Conservation (CRC). In order to make statements supported by scientific evidence, he measured greenhouse gas emissions at twenty sites in De Sijje. These measurements are made at different seasons throughout the year and linked to meteorological data, scientists can draw conclusions about the net uptake or emission of greenhouse gases in the region.

“Greenhouse gases are gases that occur naturally in the atmosphere. The two most famous are carbon dioxide and methane, but you also have water vapor, for example. Able to absorb heat.” “On the one hand, we can be very grateful for greenhouse gases, because they mean we live in a habitable world. If there were no greenhouse gases, it would be too cold to survive. On the other hand, we are currently facing a serious problem: the concentrations of greenhouse gases in the atmosphere are increasing very rapidly due to human activities. This is the cause of global warming, resulting in extreme weather phenomena.

Peat as an active and passive storage site

A peat area like De Zegge plays a crucial role in creating a sustainable balance in terms of greenhouse gas emissions. “This peat is an ideal storage place for carbon! Plants absorb carbon dioxide, which is then converted into carbohydrates so that plants can grow. This process is known as photosynthesis. In winter, some of these plants often die, both aboveground and partly underground Dead plants will decompose again, but this happens differently in peat areas than in other nature reserves. Peat areas are naturally constantly wet and low in oxygen, which means that the rate of decomposition of dead plants is very slow when an amount of pure plant material is provided More than that is broken down, this is called “active peat formation” and the carbon dioxide is then effectively absorbed into the soil and stored there as organic carbon.

Because most of our peatlands were created at the beginning of the Holocene (10,000 to 12,000 years ago), much of the carbon was already passively stored in the soil. “In the past, hundreds of years ago, a very large part of Flanders was still covered by peat, which on the one hand had already stored a lot of carbon and on the other hand also continued to actively absorb carbon dioxide. In the meantime, the 90 percent of that peat area. As a result, the peat disappears, active absorption is no longer possible, and a lot of net carbon dioxide is released. De Zegge is one of the remaining peats we currently have in Flanders. We owe this to the fact that the nature reserve was protected for a while Long Here in our nature reserve we still have local peat two to three meters deep which continues to serve as a carbon storage place so it is crucial that we continue to monitor the state of the peat and the greenhouse gas balance,” says Emsens.

Complex measurements

To visualize the carbon balance, we regularly measure greenhouse gas emissions at twenty different sites in De Sijje. The goal is to be able to withdraw the net balance at the end of the year. Does De Zegge as a whole still absorb the carbon network? Or do we release it because the peat decomposes too quickly?

The step-by-step plan for taking measurements follows a consistent pattern:

1. On top of the bottom we place a closed transparent chamber: a cocoon through which sunlight can pass. The room is equipped with fans to mix the air and sensors with which we continuously measure temperature, humidity, and light intensity.
2. We connect a greenhouse gas analyzer to this. Using this device, the concentration of carbon dioxide and methane can be measured every second.
3. The analyzer contains an air pump, which ensures that air is pumped out of the closed room continuously. This allows the concentration of greenhouse gases in the room to be determined every second. If we do that for about four minutes, you'll know whether there's a net decrease or increase in greenhouse gases.
4. Then it's time for analysis. Thanks to the WiFi connection in the room, the data is sent to the scientists' laptops, so statistical processing can continue. For example, if carbon dioxide concentrations decrease over time, we know that photosynthesis is occurring and that the plants in that transparent chamber are absorbing carbon. Sometimes we also see the opposite: an increase. This means that the respiration of plants and soil is higher than the absorption of carbon dioxide from the air. Then we have the carbon loss at that moment.
5. These measurements are not made once, but several times, as Emsens teaches: “If you want to estimate the net balance of emissions, it is very important to measure for a year, and especially to do it in every season, always in the light and in the dark.” , explains EmSense.
6. You can then correlate this data with meteorological data on light intensity and temperature to provide documented data on the net absorption or release of greenhouse gases that year.

Crucial knowledge

These measurements are important for Antwerp Zoo, so that they can closely monitor the state of the peat in De Ziege. They are also of great academic value overall and for the CRC Science Center at Antwerp Zoo, which works closely with the University of Antwerp.

“But the work we do here is fundamentally important for policy makers. Politicians are increasingly focusing on rewetting dry peat soils, but if rewetting projects are planned in the future, it is crucial that measurements are taken too. This is the only way we can During which we know whether the efforts were successful or not.

With this documented information, the Antwerp Zoo Foundation (AZF, the conservation foundation under which de Szije falls) hopes to save Peat. After all, things are not easy for the region. “The nature reserve suffers greatly from drainage. Peat is relatively dry and drier than is ideal. The drier the peat, the faster the peat decomposes and more carbon dioxide is released back into the atmosphere. Partly due to global warming, there is a greater need for wet nature in the long term, also in and around De Ziggi. It is very important that we can immediately monitor changes in greenhouse gas emissions through our measurements.

In the short term, the Aspire Zone Foundation is working to preserve the existing swamp area by managing the environmental hydrology as best as possible. This means that it will manage and improve the way water is absorbed, transported, used and consumed in De Zegge. In the long term, the Aspire Zone Foundation wants to convince the farmers active around De Ziji to grow differently and thus reduce pressure on the area. Aspire Zone Foundation encourages them to focus on successful crops in humid conditions. For example, their fields are (partially) flooded again, so they have to pump less water. In this way, the Aspire Zone Foundation wants to ensure that agriculture in the periphery coexists with the reserve in a sustainable way. Only in this way can De Sedge be saved from drought along with its unique fauna and flora such as bittern, marsh marten, porcelain grouse, grass snake, water shrew, etc.

Another step forward: large-scale measurement research

This research into De Zegge does not stop there. “Emissions research is also related to research into microbial communities of bacteria and fungi in soil. When plants decompose, that is mainly controlled by larger organisms like earthworms that cut the organic matter into pieces, so to speak, but on the other hand, fungi Bacteria are responsible for complete decomposition. In the compost heap, where there is a lot of oxygen, this process takes place very quickly, but in peat there is almost no oxygen and a lot of water and earthworms do not live there, and microbial activity is much less, which allows “By peat accumulation.”

A big question arises: Can we use these bacteria and fungi as an “indicator” of greenhouse gas emissions? “By taking soil samples during our measurements, we can use the DNA in the sample (using metabarcoding technology) to find out which microbes are present in the soil. We hope to be able to correlate the composition of this community of fungi and bacteria to the amount of methane emissions. This has not yet been achieved On an international scale, but it would make a big difference. Ultimately, greenhouse gas measurements are very labor-intensive and expensive, which means they could never be deployed on a large scale. However, if we could come up with a so-called “proxy.” “, you can estimate on a much larger scale where and when greenhouse gases will escape from the soil.