Biological invasions by non-native plant species are widely recognised as a significant component of global environmental change. Over 900 non-native plant taxa are established in the UK, of which at least 200 are widespread. These species have the potential to degrade human health, e.g. burns through contact with giant hogweed (Heracleum mantegazzianum), affect the economy as in flood defence damage caused by Japanese knotweed (Fallopia japonica), and/or threaten native biological diversity, e.g. New Zealand pygmyweed (Crassula helmsii).
CEH is one of the leading centres in Europe for the study and management of biological invasions, and we have adopted a variety of innovative approaches to the study of plant invasions.
Riparian habitats are particularly prone to invasion by non-native plants. Research funded by NERC has examined how the process of invasion is driven by environmental variables operating at different spatial and temporal scales. Climate, human population density and land use strongly determine the probability of invasion.
An example of a problematic commercial species is Prosopis juliflora, a leguminous tree introduced into north-east Brazil from Peru, which has rapidly escaped from cultivation via livestock dispersal. Our research, funded by the Darwin Initiative, revealed the strong competitive ability of the tree and its ability to limit the establishment of native tree species, many of them endemic, in the species-rich deciduous "caatinga" forest.
Our research is helping to understand why these species are such successful invaders. In consultation with local stakeholders, we are developing management guidelines by which further invasion might be reduced. In this way we are combining an understanding of ecological processes with stakeholder consultation to resolve ecological conflict.
See also Invasive Species Risk Assessment in the ALARM project (Assessing large-scale risks to biodiversity using tested methods).
See also Invasive and Non-Native Species.