An important step has been taken in combating the Watercrassula, a plant that causes the necessary problems in nature in Drenthe. The fast-growing water plant is an invasive exotic that originally comes from Australia and New Zealand. Since last month he is on the European list of forbidden invasive species.
The plant, officially Crassula Helmsiiyears ago, was brought to the Netherlands as a decorative plant for aquariums and ponds, but has since ended up in many places in nature with major consequences.
“I see it especially in Vennen and Veentjes on the Dwingelderveld and in the Drents-Friese Wold,” says forester Rudmer Veenstra of Natuurmonumenten. The plant was first seen in the Netherlands in 1995 and is now in almost the entire country.
The Watercrassula has no natural enemies in the Netherlands and is therefore growing rapidly. “Where it grows, it sometimes takes over the complete water system and expires the other plant and animal species,” explains Veenstra. “Wet areas can therefore dry out and even corrupt.”
Fighting the plant is complicated and expensive. “Removing is really a thing,” says Veenstra. “If there is only a small piece behind it, it will reset in the area again. In fact, all direct measures appear to work insufficiently.”
In the Drents-Friese Wold, an attempt is made to keep the plant manageable in some places. “In the Dwingelderveld we even slammed a fen completely, in the hope that the plant will die and we can recover the Ven later.”
Since last month, the Watercrassula is on the European list of forbidden invasive species. This means that the plant can no longer be sold, grown or imported.
“Now that it is on the list, it can be sold for another year. After that it is forbidden, but that does not mean that we will immediately get rid of the problems,” says Veenstra. “The places where the plant is already stands can still infect nature reserves. All the little bits help, but we are not yet gone.”
Want to know more about invasive exotics and the fight against this? View the explainer below: