Japanese knotweed: the "nightmare plant" haunting Scania

Sammanfattning: Invasive alien species (IAS) are one of the most important direct drivers of biodiversity loss and changes in ecosystem services. Over the last 20 years IAS are estimated to have cost the EU at least 12 billion euro per year. These costs continue to increase. Many IAS are expanding their territory, and thus both the current as well as future threat they pose must be taken into account. There is currently a lack of knowledge regarding the costs of IAS, as well as how they spread, and how they can be controlled. One such IAS present in Scania is japanese knotweed, a tall herb with far reaching rhizomes, that originates from East Asia. Japanese knotweed can both outcompete native flora and negatively affect infrastructure like buildings and roads. The aim of this project was to provide an overview of the Scanian knotweed problem, with special focus on Ängelholm municipality. Our field survey found a significant knotweed presence within Ängelholm. Knotweed stands were found in a variety of habitats including parklands, grasslands, forests and along Rönne stream. My survey of how Scanian municipalities perceive the japanese knotweed situation found that there was a problem throughout much of Scania, that many municipalities are only in recent years becoming aware of, with no clear guidelines for control efforts.