Drivers, consequences, and management of newly arriving range-shifters in the United Kingdom

There are some 1800 species living in the UK that originate from elsewhere and have been introduced by humans. Some of these non-native species are classed as "invasive", meaning they cause ruinous damage to ecosystems and/or threaten native species. However, another kind of non-native species has emerged: species that are colonising the UK without human assistance ("natural colonists"), often because climate change is creating suitable habitat for these species in the UK. Incidences of "natural" colonisation are on the rise as climate change progresses. It is increasingly suspected that some natural colonists might pose a serious threat to UK biodiversity and ecosystems. However, there is a major problem with evaluating this suspicion. Invasive impacts are assessed based on a species having high abundance across a large area, causing obvious declines in native species or ecosystem services (both of which usually require the species to have been resident in the UK for a long time), and/or being a known threat elsewhere (which requires the species to have been introduced elsewhere). Recent natural colonists have not been resident in the UK for a long time, and are rarely introduced elsewhere, so the risk they pose is un-investigated.
The studentship will perform a comparative study of the impact of several hundred natural colonists and human-mediated non-natives, based on techniques that detect early-warning signals of invasive impacts. Techniques to be used include Bayesian time-series analysis of non-native range expansion, scale-area curves, analyses of distributions between regions and time periods, Bayesian time-series analysis of local native biodiversity trends, and stakeholder consultation. The studentship will improve monitoring of non-native species regardless of their origin, and if warranted for any natural colonist species will create a species alert and monitoring scheme for that species.
The CASE partner is the NBN Trust, which manages a UK-wide partnership to coordinate the collation and dissemination of biodiversity data and analyses, sharing >110 million biological records via the NBN Gateway (https://data.nbn.org.uk/). Collaboration with the NBN Trust offers otherwise unavailable data, mobilisation of recorders to obtain new data, direct access to >150 conservation agencies across the UK with responsibility to respond to biodiversity threats, and the potential to develop new early-warning schemes if warranted. The studentship is also in collaboration with NERC's Centre for Ecology and Hydrology (CEH), the UK's centre for excellence in terrestrial and freshwater science, which conducts high quality research projects on nationally-important datasets. The CEH supervisor is a world leader in scientifically dissecting biodiversity data, offering the student training in Bayesian hierarchical modelling and correcting for recorded bias, both of which are essential to the project. The student will therefore be trained in highly novel science, and the means by which science can inform conservation strategies.