Invasive alien species (IAS) are considered one of the greatest threats to biodiversity, particularly through their interactions with other drivers of change. Horizon scanning, the systematic examination of future potential threats and opportunities, leading to prioritization of IAS threats is seen as an essential component of IAS management. Our aim was to… (More)
There is growing concern about increased population, regional, and global extinctions of species. A key question is whether extinction rates for one group of organisms are representative of other taxa. We present a comparison at the national scale of population and regional extinctions of birds, butterflies, and vascular plants from Britain in recent… (More)
Habitat quality Pollinators Conservation A B S T R A C T We assessed national scale changes in the forage plants of bumblebees in Britain, as a means of providing quantitative evidence for the likely principal cause of declines in bumblebee species. We quantified the relative value of native and long-established plant species as forage (nectar and pollen)… (More)
These notes give an elementary approach to parts of the theory of standard Borel and analytic spaces.
Information on non-native species (NNS) is often scattered among a multitude of sources, such as regional and national databases, peer-reviewed and grey literature, unpublished research projects, institutional datasets and with taxonomic experts. Here we report on the development of a database designed for the collation of information in Britain. The… (More)
The intention of these notes is to give a mathematical account of how I believe students could be taught to think about functional programming languages and to explain how such languages work.
These notes present an approach to obtaining the basic operations of addition and multiplication on the natural numbers in terms of elementary results about commutative monoids.
These notes present an approach to obtaining the basic properties of the natural numbers in terms of the properties of finite sets (which are introduced independently of the natural numbers). The role played by the usual recursion theorem is taken over by a construction which can be regarded as a recursion theorem for finite sets.
Conservation biologists have only finite resources, and so must prioritise some species over others. The EDGE-listing approach ranks species according to their combined evolutionary distinctiveness and degree of threat, but ignores the uncertainty surrounding both threat and evolutionary distinctiveness. We develop a new family of measures for species,… (More)
This note presents an approach to obtaining monoid operations which are compatible with a given family of mappings. This can be applied to the addition on the natural numbers defined within the framework of the Peano axioms as well as to the concatenation of lists.