The concept of essential variables is well established (Figure 1), and their success has helped unlock funding and resources for the production of data products useful to guide policy. Currently, ecosystem service science lacks data standards but the burden of reporting is increasing in both the public and private sectors. While EBVs have matured into scalable, interoperable and standardised data products, EESVs have only been conceptualised recently, with six classes proposed to organise them (Balvanera et al., 2022). Little work has yet been done to develop the variables to populate these classes (Schwantes et al., 2024).

EESVs are intended to be theory driven, developed by academics to enable complete and effective monitoring of biodiversity and ecosystem services, rather than the practical data driven approach taken in the development of many existing indicators. To learn more about the historical background and development of essential variables, please read our short introductory document to EESVs here.

 

 

 

Figure 1. Essential variables summary. Essential variables helps organise observations into standardised scalable products that are feasible, relevant and cos-effective to measure. These criteria are applicable to any Earth system (e.g. climate, biodiversity or ecosystem services)

Developing EESVs

Learning from the strengths and weaknesses of the EBV development can support GEO BON’s ESWG to develop the EESVs. Contrary to EBVs, EESVs have been proposed classes first. That is, the key aspects of ecosystem services to monitor and organise essential variables by have already been identified but none of the variables have been proposed (Figure 2). Six classes of EESVs have been proposed to date:

  • Ecological supply refers to the ecosystem’s potential capacity to provide ecosystem services
  • Anthropogenic contribution refers to the knowledge and efforts that humans invest to enhance ecological supply and to make use of ecosystem services.
  • Demand refers to the explicitly or implicitly expressed human desire or need for an ecosystem service, in terms of its quantity or quality, irrespective of whether awareness exists about such need
  • Use refers to the active or passive appropriation of an ecosystem service by people; highlights the actual appropriation of benefits from nature.
  • Instrumental value refers to the importance of an ecosystem services to societies or individuals as a means to achieve a specific end
  • Relational value refers to the importance ascribed to how ecosystems contribute to desirable and meaningful interactions between humans and nature and between humans in relation to nature

Ecosystem services are highly context-specific, depending on the ecosystems, cultures and socio-ecological systems in which they arise, making it difficult to identify EESVs that can be aggregated from local to regional to global scales. Additionally, identifying a single variable to measure each aspect of an ecosystem service is not always straightforward (e.g. wholesale value vs retail value as a measure of the instrumental value of a fish provisioning ecosystem service) and the heterogeneity of methods used to collect data relevant to ecosystem services requires harmonisation to produce single EESVs. In many cases selecting appropriate units and scales of measurement also requires careful consideration. Moreover, there are significant scientific and infrastructure costs to developing essential variables. Finally, prioritising which EESVs for which ecosystem service to measure and report on requires participatory approaches and engagement with policymakers to focus development efforts on those EESVs that are of a higher priority. The ESWG will need to take into consideration each of these challenges in developing EESVs for specific ecosystem services and within each class.

Figure 1. Essential ecosystem service variables in practice. Ecosystem service-relevant observations are organised into the appropriate EESV class to produce essential ecosystem service variables that can be used in the compilation of indicators.

Going forward

Ecosystem service science suits itself well to the essential variable concept as many EESVs are likely to be model outputs using multiple data input sources (e.g. InVEST or ARIES). Developing practical and useable EESVs that are accessible to stakeholders will therefore be beneficial both for the academic community and for society.

The complexity of ecosystem services makes a class-by-class approach impractical. Expertise tends to be focused on specific social-ecological systems, suggesting that it may be more appropriate to develop EESVs by ecosystem service. Having pre-defined classes provides the theoretical background and framing required to organise EESVs but specifically identifying the available data and methods to produce EESVs should be done by those communities of experts most familiar with each ecosystem service.

In addition, due to the distinct conceptual and real differences between provisioning, regulating and cultural services, it may be necessary to consider dividing EESVs and their classes per type of ecosystem service to allow for aggregation and indicator compilation of fundamentally different ecosystem services (i.e. not attempting to aggregate regulating with provisioning services).

This bottom-up approach may highlight some limitations in the current conceptualisation of EESVs which would require revisiting the pre-defined classes. We suggest that the ESWG should remain open-minded to this possibility, especially if it allows streamlining of data needs and reporting efforts.

Considerable work has already been done to develop ECVs, EOVs and EBVs with some overlap becoming apparent in both data needs and outputs. Taking advantage of current efforts to align EESVs with other essential variables and enable joint monitoring through sharing of resources should be considered a key priority to help accelerate the development of EESVs.

Given the urgent need for effective monitoring of ecosystem services, the ESWG should make all possible efforts to develop EESVs in conjunction with those stakeholders who need them (e.g. governments and corporations). This would help prioritise between EESVs and generate interest in supporting the development, deployment and testing of this tool.

 

References

Balvanera, P., Brauman, K.A., Cord, A.F., Drakou, E.G., Geijzendorffer, I.R., Karp, D.S., et al. (2022). Essential ecosystem service variables for monitoring progress towards sustainability. Curr. Opin. Environ. Sustain., 54, 101152. 

Muller-Karger, F.E., Miloslavich, P., Bax, N.J., Simmons, S., Costello, M.J., Sousa Pinto, I., Canonico, G., Turner, W., Gill, M., Montes, E. and Best, B.D., 2018. Advancing marine biological observations and data requirements of the complementary essential ocean variables (EOVs) and essential biodiversity variables (EBVs) frameworks. Frontiers in Marine Science, 5, p.211.

Schwantes, A.M., Firkowski, C.R., Affinito, F., Rodriguez, P.S., Fortin, M.J. and Gonzalez, A., 2024. Monitoring ecosystem services with essential ecosystem service variables. Frontiers in Ecology and the Environment, 22(8), p.e2792.