Abstract
Moving towards policy-relevant ecology requires efforts aimed at understanding and accounting for interactions between humans and the natural environment. The home base of ecology has always been the natural environment. The hotspots of human activities and economies, however, are the cities. Urban environments, with dense human populations, intensive and highly diverse land use, transportation networks, etc. offer great opportunities for studies of interactions between humans and nature. Many cities are situated in areas with high biodiversity and thus constitute both human and biodiversity hotspots.
I will present some ongoing work on biodiversity in Oslo, which harbors the highest human population and the highest biodiversity in Norway. This work has several aims of importance to policy-relevant ecology, including quantification of rare biodiversity elements (species, ecosystems), modelling effects of human pressures, and defining and estimating states and reference values for assessments of ecological condition and ecosystem accounts. I will illustrate opportunities and challenges related to these aims based on analyses of biodiversity surveys and open biodiversity data from several projects and sources (including URBAN-EEA and GBIF). For instance, rare (and thus often highly valued) biodiversity elements are not easily captured in standard surveys and are often over-represented (with unknown bias) in open occurrence data, but can be captured with probability-based sampling. A preliminary statistical model for limestone-associated plant species in Oslo suggests that the occurrence of these species is determined by a combination of ecological conditions and human land use. With such models we can estimate the current state of this biodiversity element across Oslo, and assess the magnitude of human impact. This may serve as a starting point for defining and estimating reference states and building biodiversity and ecosystem accounts. All of this does, however, involve uncertainties at several levels, which also constitute an important challenge for policy-relevant ecology.