Invasive Species

Native plants form communities where the various plants (and associated animals and fungi) have been together for long enough for there to be a balance in the way they compete with each other. If a plant from a different part of the world is introduced, the balance can be upset. These introduced plants have several potential advantages. They may well have arrived without the predators and diseases that keep them in check in their native range. They may possess some special features of metabolism or dispersal that is not possessed by the local plants. If so, they have a competitive advantage and can rapidly colonise large areas.

Why are invasive plants a problem?

Non native invasive plants are a huge problem across the globe. They are a major cause of extinctions and degradation of habitats. In places like Hawaii, much of the native vegetation has been displaced. Not only do the native plants disappear but also the animals that have evolved to live with them.

The British Isles has escaped relatively lightly, although over a thousand non-native plants have become established in the wild, only a small number have so far become invasive. Many of the introduced species come from warmer parts of the world and grow with reduced vigour in the cooler British climate may reduce their vigour. Also, Britain is a densely populated country. Most of the land farmed intensively. Few species can establish and become invasive in this type of landscape. With the expected temperature rises due to Climate Change, invasive species may well become more of a problem.

Role of the National Park

National parks were set up with the purpose of conserving and enhancing natural heritage. The Snowdonia National Park Authority has been taking action against invasive species for over thirty years. We have organised meetings and conferences, giving grants and undertaking control in our own woodlands. The focus throughout has been on Rhododendron control as this is regarded as the biggest threat. The latest phase of the Authority’s work began in 2005 with the launch of the Invasive Species Project. The project, which is funded by European Objective 1 money has two main aims. One is to devise a Park-wide strategy for the future control of rhododendron. The second is to undertake local targeted programmes of eradication.