Biodiversity and climate

Climate change is threatening biodiversity in the Netherlands both under water and above it. Action is required, but where do you start? Together with its partners, Witteveen+Bos has developed two stress tests: one for water quality and one for biodiversity. These tests help answer a key question: Which waterbodies and areas of land are vulnerable to climate change and which are more resilient?

Vulnerable

Together with Ambient, Witteveen+Bos developed the water quality stress test for STOWA for application on DPRA (Delta Programme for climate change adaptation). It gives water managers – local governments, water authorities, and the national government – a handy tool for identifying climate-related vulnerabilities in their water systems.

The water quality stress test has already proven its practical worth, including on projects by the water authority Hollands Noorderkwartier and water authority Amstel, Gooi en Vecht, the Province of Overijssel, and Rijkswaterstaat. Together with the different Rijkswaterstaat regions and Witteveen+Bos, Rijkswaterstaat investigated the climate vulnerabilities of all 54 WFD waterbodies.

The investigation revealed that each waterbody is somewhere between vulnerable and very vulnerable. The causes vary widely from one water system to another, but the same factors occur remarkably often. These include high nutrient levels, high toxicity, limited ecology, and a lack of natural dynamics. Rijkswaterstaat plans to consider the outcomes and use them to programme and prioritise.

Biodiversity

The second test is the biodiversity stress test, developed by Witteveen+Bos for the Ministry of Agriculture, Fisheries, Food Security and Nature. This test identifies the vulnerability of biodiversity to climate change using abiotic factors.

In terms of method, the biodiversity stress test works the same as the water quality stress test. The difference is that it tests whether the preconditions for terrestrial flora and fauna are sufficiently present to ensure a healthy habitat – now and in the future. The test was developed for the whole of the Netherlands but first refined for application with sandy soils in high-lying areas. In the near future, the biodiversity stress test will almost certainly be adapted to and used for other soils, such as clay soils.

Solid foundation

With the development of both these tests, Witteveen+Bos is making an important contribution to conserving and protecting our natural environment both under water and above it. The stress tests offer a solid foundation that provides water managers, site managers, and governments in a broader sense with tools for tackling current and future challenges.