Nature Capital Model

Why a Dutch Natural Capital Model?

The Dutch governments strives for a strong and resilient nature in the Netherlands that contributes to people’s well-being, including social and economic welfare in the broadest sense. Nature and nature’s contribution to people has also gained a prominent place within the European policy arena (like in the European Green Deal), calling for the protecting, restoration and sustainable use of nature.

The Natural Capital Model is designed to inform and support especially policy makers in operationalize nature’s contribution to people in decision-making. To do so, the model provides insights into the physical benefits that Dutch nature deliver to people like pollination, water provision and nature-based recreation. The model shows for each location in the Netherlands which ecosystem services and how much is or could be delivered by nature.

The Natural Capital Model serves multiple purposes. It can assess the current state of ecosystem services in the Netherlands. Over the past years, the model has also been used to assess the effect of future developments, scenarios or proposed policies on the delivery of ecosystem services. Also, the model can be used to quantify the contribution of nature to address certain societal challenges or policy objectives (e.g., mitigating climate change by natural carbon sequestration or ensuring a livable city with green space for recreation, shadow and water collection). The model is developed for application at a national and regional level, but could be applied a lower scale as well.

Sub-models

The Natural Capital Model consists of a set of sub-models (see model documentation). Each sub-model quantifies a different ecosystems service. Currently, there are 13 ecosystem service sub-models, covering i) provisioning services (drinking water supply, wood production, biomass production (for energy)), ii) regulating and maintenance services (pollination, pest control, soil fertility, water retention, urban cooling, water purification, carbon sequestration, air quality regulation) and iv) cultural services (outdoor recreation, natural heritage). The figure below shows the ecosystem services currently covered in the Natural Capital Model (colored).
Some ecosystem services are particular relevant to certain landscape types, such as agricultural areas with ecosystem services like pest control and pollination, forests like biomass and wood production, and urban areas like air quality regulation and urban cooling, but most models are designed to allow assessment across multiple landscapes (urban, rural and natural ecosystems).

How can the model be used?

The model can be used to answer a range of different questions. For example, the National Institute for Public Health and the Environment (RIVM) uses the model to identify and map the current Dutch ecosystem services. Statistics Netherlands (CBS) is collaborating with Wageningen University (WUR) to map the relationship between nature and the economy in the Netherlands and to monetize the effects. PBL and WUR use the model to calculate future changes in ecosystem service delivery and to explore policy options of nature-based solutions for certain societal challenges.

How does the model work?

Each ecosystem service sub-model builds on quantitative relationships between the ecosystem service and various variables (e.g., land use, management and hydrology). These relationships are derived from literature review and expert judgments. Each sub-model quantifies both the supply (capacity of nature to provide a service) and demand (societal needs, preferences or desire for a certain service) of an ecosystem service. Subsequently, the model compares supply and demand to assess the degree of realization or benefit to people. This means that an ecosystem services is only realized if the societal demand for this service is met by the ecosystem’s capacity to deliver that service. For example, pollination services are only realized if ecosystems that support wild pollinators (supply, e.g., natural grasslands, flower strips) are close to agricultural fields with pollinator dependent crops (demand).

Model outputs differ among each sub-model, in terms of ecosystem service indicator and associated unit (e.g., wood productions in terms of m3 wood per hectares). To make model outcomes comparable, each sub-model calculates the match of supply and demand, presented in relative terms (percentage of supply which meets demand). This supply-demand approach also helps to identify the degree of mismatch between supply and demand.

Key input data to assess ecosystem service supply are land use, land management information and additional environmental variables (e.g., soil moisture, availability of nutrients, pH, air quality). Societal demand is based on the need to avoid or reduce potential impacts (e.g., decline in crop production due to absence pollinators, heat stress due to increasing temperature), to meet common policy goals or norms (e.g., water and air quality norm, Paris climate agreement), consumption needs (e.g., Dutch wood demands) or people preferences (e.g., recreation activities).
The Natural Capital Model is a largely automated calculating system. With the right input data a standard set of indicators can be generated. Standardizing and automatizing makes it easier and more reliable to run and rerun the model. Standardizing is needed for monitoring the development in time. At the same time several research institutions further develope the Natural Capital Model to increase its scientific quality and applicability to meet a broad range of spatial planning issues and policy context.