When drained, peatlands, which are a special type of wetland characterized by peat soil, release huge amounts of stored carbon. In the EU, about 50% of peatlands are drained. In the Netherlands, “they emit 5% of anthropogenic greenhouse gases, and that’s on only 0.3% of the earth’s surface,” explains Vroom.
The main problem with restoring wetlands that have been used for agriculture is the addition of excess nutrients. These nutrients, such as artificial fertilizers, were beneficial for the crops grown there, but when the wetlands are restored, they leak out, affecting the water quality. In addition, they lead to the appearance of algae and a small number of plants that quickly take over the bog, meaning that biodiversity and normal functioning of the bog are not restored.
Vroom’s work has shown that paludarium, the practice of growing harvestable plants in wetland ecosystems such as peatlands, can be used to gradually return land to a natural state.
Bringing Drained Wetlands Back to Life
The term “paludiculture” was coined in 1998 by Hans Josten, a professor at the University of Greifswald. Proposed as an alternative to draining wetlands, particularly peatlands, for agriculture, the practice has been successfully used in peatlands in Southeast Asia, the Caribbean and South America.
Research into paludiculture in Germany shows that these operations improve biodiversity compared to drained farms. Hybrid forms of paludiculture that include fisheries are also being tested in countries such as Indonesia.
According to Vroom, the paludarium plays a special role in the revitalization of wetlands by removing excess nutrients left over from drainage and cultivation.
Plant species such as cattails or duckweed are highly productive, and if planted early in the irrigation process, they act as sponges for excess nutrients in the system, which are removed and turned into an economic product. For example, the tailings can be used to make insulation materials or as a component of cow feed. At the same time, the natural balance of plants and animals is given time and space to recover.
Researchers like Vroom will be closely monitoring the long-term health of ecosystems irrigated using this method in the future. Despite promising efforts, it is unclear whether the level of biodiversity productivity and wetland function will return to their previous state.
“People often say that more research is needed, but more and more research is showing that these methods work very well,” says Vroom. “The most important thing is that the wetlands are restored.”
Given the large amount of greenhouse gases emitted in such a small area, Vroom is optimistic that wetland restoration could make a significant difference in the fight against climate change. “It’s a fairly small area of land where you have to do something to make a really big difference,” says Vroom.
