The biodiversity intactness model (BIM) measures how abundance of species differs under current conditions (which take into account human footprint features) from what would be expected if there was no human footprint (known as “reference conditions”). This difference between the current and reference species abundance is calculated for hundreds of individual species and then averaged across species to obtain an overall index of biodiversity intactness. For example, the model can explore expected species abundances with the current human footprint (e.g., roads, buildings, farms, etc.) compared with alternative future land-use conditions. Intactness declines as species abundances decrease or increase relative to reference conditions, so that a declining population or an invasive or overabundant native species all have negative impacts on biodiversity intactness.
The capacity to represent biodiversity intactness as a function of human footprint is built into a platform that allows for integration with other ecosystem service assessments. Biodiversity, as an ecosystem service, is assessed using the ABMI’s core field monitoring data as well as sampling from 24 “off-grid” sites of relatively undisturbed southern Alberta rangelands and relatively disturbed regions of the boreal forest.
Result of the assessment is a numeric measure without a dollar value or trading value attached. In order to take a market approach to enhance biodiversity, such as a biodiversity offset system, Biodiversity intactness units or equivalencies should be created. These units could be related to the costs associated with buying a piece of land or expenses for creating habitat.