ZONATION – PLANNERS´ LITTLE HELPER

Zonation is a quantitative decision support tool for spatial conservation planning, developed for solving various problems around spatial management and resource allocation. Zonation was developed in CBIG – Conservation Biology Informatics Group in the department of Biosciences of the University of Helsinki. The team was led by the professor Atte Moilanen who is currently part of the Digital Geography Lab. Zonation and user manuals (Fig. 1) are downloadable here.   

Fig. 1. Zonation user manuals, along with the actual Zonation tool, can be found online.

Zonation is a spatial prioritization tool, where different interests (e.g. ecology, costs) are balanced in a way that loss of biodiversity is kept as low as possible. Zonation eats huge amount of spatial data, such as information on ecology or threats to biodiversity (Fig. 2), and synthetizes information in a way that most important areas (for purpose in question) can be identified.

Using Zonation, one could ask questions (and receive answers) related to (and not limited to):

  • Reserve planning/selection, expansion, evaluation of proposed/existing reserve network
  • Impact avoidance – identification of ecologically low-value areas for economic use
  • Target-based planning
  • Biodiversity offsets – areas for ecological compensation
  • Planning under changing environment
  • Habitat restoration/management
Fig. 2. Zonation is about spatial prioritization, where different interests are balanced depending on question at hand.

Zonation produces a hierarchical, iterative prioritization across the landscape based on the value of a site (cell), which depends on e.g. amount of data and weights given. Zonation first removes the least valuable cells from the landscape, while at the same time minimizing the loss to biodiversity. This means that areas you would not like to conserve would be dropped out first. Terrestrially speaking, areas for instant go would be parking lots, dense urban areas, etc. while untouched forests with rare habitat types, threatened species, etc. would stay until the end (and given highest priority rank). At sea, analogous marine environments would be for instance, hypoxic areas and shallow bays with dense vegetation and low human-induced disturbance, respectively.

As a result of Zonation analysis, you get a sequence of cell removal, and curves telling at which point each feature (i.e. threatened species) is lost (Fig. 3). For instance, for reserve network evaluation, you could get an idea how much of a species X (you are interested in), is at the moment conserved, and what (and where) needs to be done to conserve it more.

Fig. 3. As an example, the left figure represents a result from spatial prioritization operation (the ranking) from the Finnish sea areas, where important underwater nature value areas were identified, and the present MPA network evaluated. Black and red areas are of high value and light blue of lower value. On the right is the other main Zonation output, telling how much the current MPA network protects underwater nature values. For instance, Habitats Directive Annex I Habitats are well protected by the current network (~40 %), which is not surprising if considering Natura 2000 establishment criteria. Figures adopted from: https://www.frontiersin.org/articles/10.3389/fmars.2018.00402/full

From the impact avoidance point of view, you could also get an idea, where the least valuable areas are located. Areas of low value would be suitable for instance for economic purposes or for other human activities. Compared to the least valuable areas, those with high value are areas with high species richness, threatened and rarely occurring species, connected habitats etc. (Fig. 4).

Fig. 4. Examples of type of reasons why site value is increased and decreased in spatial prioritization.

How does this relate to sea and especially to SEAmBOTH? Well. Analytically, it does not matter whether areas to be analysed are land- or sea-based. What does matter is that there is enough (high-quality) data for doing stuff like this. Zonation is an attractive option for synthetizing information for the use of marine spatial planning, as one can solve questions related to sustainable use of the sea, while accounting for interests in economic development (e.g. offshore wind-farms), and for conservation (marine conservation areas). In SEAmBOTH, we are going to identify most valuable underwater areas, which will be species rich, contain threatened and rarely occurring species, have a higher number of ecosystem engineers, and be well-connected and less disturbed. How we are actually going to do that requires co-operation and a lot of GIS-stuff. Stay tuned!

Written by Elina Virtanen, Finnish Environment Institute

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