The City of Oslo’s built-up area spans 15,270 ha, where 18.5% are urban green spaces, being 1% cementeries, 14.44% public open spaces and 3.1% parks. Parks are managed green spaces within the built zone. Public open spaces (‘‘friområder” in Norwegian) are largely unmanaged green spaces within the built zone open to the public. We refer to parks, public open space and cementaries as collectively referred to as ‘‘green space”. Six percent of the Oslo Municipality is fresh water, with ten main streams running through the urban area.
The city is situated at the end of the Oslo Fjord, and is surrounded by seawater and islands to the south, and boreal forests to the North and East (Oslo European Green Capital 2016 Application). Oslo had 624,000 inhabitants in 2013, and population projections indicate that the city will number about 800,000 people in 2030 (Oslo Municipality, 2015). National and municipal protected areas for conservation make up almost 10% of the area in Oslo municipality, and are located in the built-up area, on islands and in the surrounding forest. The fjord and the forests, combined with the city’s green spaces, waterways and islands, constitute a unique blue-green infrastructure, providing multiple ecosystem services for Oslo’s residents, including valuable habitats for biodiversity conservation in Norway (Soy Massoni et al. 2028).
We aim at assessing key properties of the soils in Oslo green areas and features, especially those that are related to carbon uptake and storage and other regulating functions of urban soils. Our purpose is to identify indicators and protocols that could be used to monitor the condition of Oslo’s soils.