Cycads, Japanese knotweed and invasive species

Wildlife campaigners are calling for a ban on soil imports into the UK to stop invasive species from contributing to Britain’s wildlife crisis. Insects, seeds and microorganisms found in the soil, compost and potted plants are competitors and threaten to feed on native species. Examples of invasive species are the New Zealand flatworm (Arthurdendyus triangulatus), the Spanish Slug, the Asian ladybug and the harlequin ladybird. Over 350,000 tonnes of plants and soils were imported to the UK in 2021.

Japanese knotweed (Reynoutria japonica) was once considered an attractive import plant and now has a reputation as a sinister, garden-destroying enemy. It spreads slowly and relentlessly and takes over metres of land until it dominates all other plants. In much of Europe and North America, knotweed has conquered forests, pastures and urban wastelands. According to one of the Welsh experts, the largest knotweed stand he encountered covered over 20,000 hectares – almost as much space as four Boeing 747 planes.

Present on Earth for 280 million years, cycads are threatened with extinction due to illegal trade and disappearing tropical forests. The rarer they are, the more valuable they become, with some individual specimens selling for millions of dollars. The loss of such rare plants removes their gene pool from the natural environment, reduces their numbers and brings them closer to extinction. Poachers destroy entire plant habitats, and smuggled specimens are at risk of disease.