How to preserve biodiversity when planning urban land use

Joel Jalkanen’s doctoral thesis in geoinformatics demonstrates that spatial conservation prioritisation is a sensible tool for planning land use in growing and condensing urban areas. His practical case study carried out in the Uusimaa region and the Helsinki Metropolitan Area offers assistance to land-use planning professionals and municipal decision-makers.

Flowers or streets?

Conservation prioritisation serves as a discussion tool, a platform and a basis for decisions.

“With different interests coming face to face, spatial prioritisation can help identify the most valuable areas in a systematic manner and from the perspective of cost-efficient conservation,” says Joel Jalkanen, who is currently working as a planner specialised in the natural environment in the City of Espoo Planning Department.

In his research, Jalkanen applied Zonation, a computer program developed at the University of Helsinki that is a freely available tool for decision-making. Zonation can be used in ecologically based land-use planning as well as in solutions associated with planning conservation areas and avoiding ecological harm.

While comprehensive data on the natural environment of the area in question is essential to conservation prioritisation, another thing that is important to understand is how urban biodiversity is perceived and how it is designed as part of flexible and sustainable green areas.

According to the doctoral thesis, safeguarding the diversity of urban environments requires the preservation of several habitats of different types that supplement one another’s species, such as urban forests, coastal meadows and botanic gardens.

Bringing green areas within the reach of residents

Subjecting areas to conservation prioritisation is a practical method also for ensuring equal access to recreational opportunities when planning green structures.

“Central green areas alone are not enough to provide equal recreational opportunities for the entire population of the Helsinki Metropolitan Area. In addition to them, it is important to consider the green areas of the fringes as well,” Jalkanen notes.

Results of spatial prioritisation analyses for green areas in terms of urban biodiversity (left) and equal access (right). The valuation of green areas varies considerably depending on the perspective taken.

An element of regional planning

Conservation prioritisation has been applied to regional planning in Uusimaa. Key to employing conservation prioritisation in land-use planning is the collection of environmental datasets on the basis of careful planning, as well as integrating prioritisation into the existing zoning and decision-making processes.

Conservation prioritisation can also help identify ecological networks and connections. On the regional scale, avoiding the fragmentation of extensive and uniform areas may be more important than preserving individual narrow corridors.

Sections of the doctoral thesis:

  • How can urban biodiversity be examined in spatial prioritisation analyses?
  • Spatial prioritisation in the identification of the most important urban green areas and in terms of equitable access
  • Experiences of using Zonation for regional planning in Uusimaa and how spatial prioritisation should be integrated into zoning processes
  • Identifying extensive ecological networks and regional-scale connections with the help of Zonation


An outline of the systematic utilisation of conservation prioritisation as part of inclusive and ecologically sustainable land-use planning. Conservation prioritisation results describing biodiversity and recreation values can be compared iteratively in relation to land-use goals and interests, identifying three types of areas: new conservation areas; areas where land use would support both human activity and biodiversity values; and areas where land-use interests other than conservation would be prioritised. Open and transparent prioritisation analyses require broad-based inclusion in both planning the analyses and interpreting the results in the context of land use.

Joel Jalkanen, MSc, will defend his doctoral thesis entitled ‘Spatial Conservation Prioritization for the Benefit of Urban and Regional Land-use Planning’ on 27 November 2020 at 12.00 at the Faculty of Science, University of Helsinki. The public examination will take place in room 107 of the Athena building, Siltavuorenpenger 3 A.

Associate Professor Niina Käyhkö from the University of Turku will serve as the opponent and Professor Tuuli Toivonen as the custos.

The thesis will be published in the series Department of Geosciences and Geography A88.

The thesis Spatial Conservation Prioritization for the Benefit of Urban and Regional Land-use Planning is also available in electronic form through the Helda repository.

Contact details of the doctoral candidate:
Joel Jalkanen,, phone: +358 40 704 2208