Habitat types for built environment – what are they good for?

At the end of March, the ARVO and BOOST projects published a draft document on habitat classification and ecological assessment criteria for the built environment. The materials were produced in close cooperation with experts during the winter of 2024–2025. Once again, we would like to thank the skilled and committed experts who defined the criteria for habitat types in the built environment! The feedback we have received has been interested and appreciative, but the work has also raised the question: how do habitat types in the built environment relate to natural habitat types?

BOOST and the Finnish Environment Institute’s Ecological Compensation Pilot Project published guidelines for assessing the ecological status of natural habitats and peatlands earlier this year. These guidelines enable nature to be “measured” in nature value hectares and ecological compensation to be implemented in practice in accordance with the Nature Conservation Act. In this context, “natural habitat types” refer to habitat types listed in the Red Book of habitat types. With the exception of peatlands, these assessment guidelines did not cover the nature in urban areas and other environments created or heavily modified by humans, which cannot be defined as natural habitats but whose importance for biodiversity should not be overlooked. In urban areas, various park and yard areas in particular maintain a wide range of biodiversity, the quality or quantity of which has not yet been assessed in a consistent manner.

Descriptions of habitat types in the built environment and criteria for assessing their ecological status meet the above-mentioned need. They enable the determination of nature value hectares for nature in the built environment in the same way as for natural habitats and peatlands. Now, for example, the impacts of land use projects on nature – both man-made and naturally occurring – can be comprehensively and consistently assessed in terms of nature value hectares.

Nature value hectares in the built environment cannot be used for ecological compensation

It is essential to understand that although nature in the built environment can now be measured using the same unit as natural habitats and peatlands, natural value hectares in the built environment cannot be used for ecological compensation. The Nature Conservation Act, which regulates ecological compensation in Finland, only applies to endangered habitat types. As far as we know, there are no plans to introduce any rules on compensation for nature in the built environment, such as exchange rules between habitat types. The newly published classification of habitat types in the built environment does not have the same official status as the Red Book of habitat types, although we hope that it will become established in practice.

This means that if, for example, a city plans to develop a heath forest (a natural habitat type), it cannot claim to compensate for the damage to nature by establishing ecologically high-quality wooded parks (a habitat type in the built environment), even if the number of nature value hectares is the same.

Nature value hectares support a wide range of nature work in the built environment

Instead of ecological compensation in accordance with the Nature Conservation Act, nature value hectares can be used extensively to measure and monitor the effects of measures that weaken or improve nature, including in built environments. Examples of suitable applications include:

  • Comparing land use options based on their impact on nature.

  • Planning the management of green areas in a nature-friendly and enriching way.

  • Planning, implementing and verifying new environments.

  • Planning and verification of various nature-based measures, for example as part of corporate or municipal responsibility initiatives. Nature-based measures are various actions that support, increase and safeguard the state and diversity of nature, but do not meet the criteria for ecological compensation.

The recently published descriptions of habitat types in the built environment and spatial indicators enable comparisons between different occurrences of the same habitat type. However, they do not in themselves indicate the extent to which each habitat type maintains or supports biodiversity, nor do they indicate the uniqueness or conservation value of the species found in the habitat types. This is also the case with nature value hectares: one nature value hectare of deciduous forest is not the same as one nature value hectare of stream or rocky outcrop in terms of nature.

The prioritisation of different habitat types in land use planning, for example – i.e. deciding what nature to preserve or what kind of nature to create – is a separate issue that may require separate assessment criteria. Ecologically sound solutions are ultimately always made on a case-by-case basis, based on expert assessments and opinions.

The key role of nature value hectares is to serve as a verifiable and ecologically sound unit of measurement for assessing the impacts of land use, both harmful and beneficial. The new possibility of comprehensively classifying habitat types and determining their ecological status provides a basis for transparent, comparable and long-term planning, decision-making and monitoring.

Joel Jalkanen (University of Helsinki, BOOST)

Eini Nieminen (University of Jyväskylä, BOOST)

Elisa Lähde (Aalto University, ARVO)

 

The ARVO project (10/2023-12/2025) aims to strengthen green infrastructure and identify its values in densely built cities in order to promote adaptation to climate change. The project is coordinated by the City of Helsinki. The project partners are Aalto University, the City of Espoo, the City of Vantaa and Green Building Council Finland. The project is funded by the European Regional Development Fund.

News 24.3.2025