Over the last millennia, humans have deliberately moved species around the globe, mainly for economic or amenity reasons. Farming, forestry and horticulture are just some of the many industries that have benefited from the presence of non-native species.
A number of species have also arrived in Scotland accidentally, for example in consignments of goods from abroad or in the ballast water of ships.
A number of non-native species have become valued parts of our biodiversity, whilst others have failed to survive in our environment. However, a small but significant proportion of introduced species have not only established, but thrived in Scottish ecosystems, assisted by a lack of predators and diseases to control their numbers. These species are referred to as Invasive Non-Native Species (INNS) and they threaten our native biodiversity and rural industries and cost the economy millions of pounds every year.
In addition to INNS, a number of native species can also become invasive if the habitat is altered in some way to give the species an advantage. In these situations, native species can also have a significant negative impact upon the environment.
The South Lanarkshire Biodiversity Partnership has identified 9 invasive species which it considers to be a priority for action. These are:
Rhododendron ponticum and its hybrids
The Partnership has established a working group which has responsibility for the monitoring and surveillance of invasive species. This is an essential task as it is much easier to eradicate invasive species before they have chance to establish a viable population in a new area. Early detection is crucial and sightings of invasive species should be reported as soon as possible. A leaflet and a poster have been created to raise awareness of the issue in South Lanarkshire
With already established species, a key priority is to understand their distribution and extent. It is often impossible to eradicate invasive species, but this problem is compounded when areas are cleared only to be "re-infected" by neighbouring or upstream populations. The invasive species working group is currently undertaking a project to monitor and record the distribution of the priority invasive species, so that a strategic control programme can be developed in the future. The group has developed an Invasive Species Position Statement which assesses the current status and knowledge regarding each of the priority invasive species.
The LBAP uses invasive species as an indicator of poor ecosystem health. Each ecosystem plan has a specific long term aim, and associated actions, with regards to the monitoring and control of invasive species. The Biodiversity Strategy also has an Invasive Species Plan, which contains more generic actions regarding invasive species.
In order to successfully monitor the extent of invasive species, sightings from the general public and local interest groups (such as dog walkers, ramblers and anglers) are essential. The list of species above have links to factsheets helping you to identify them, whilst a recording form with more information and images can be downloaded here. Sightings can also be submitted via the Planttracker app, available here: http://planttracker.naturelocator.org/