Collaborative dune grasses make climate-resilient dunes feasible and affordable

Dune restoration is becoming increasingly important due to rising sea levels and stronger storms. Paul Berghuis and colleagues from NIOZ Royal Netherlands Institute for Sea Research and Utrecht University showed in the dunes of Texel that dune grass patches “collaborate” to capture sand, even when they are still meters apart. Their crucial discovery for efficient dune restoration was published on 19 March 2026 in Nature Communications.

Fight against the water

Dutch dikes are world-famous, but we have also been building dunes for centuries. The first artificial dunes (so-called “drift dikes”) were already constructed in the 15th century. More recently, near Petten around 30 million m² of sand was pumped up to form the Hondsbossche Dunes. These artificial dunes are starting to resemble natural dunes, but important differences remain.

Natural dunes are resilient

Artificial dunes function like a dike: they often consist of a single high, robust dune that keeps out seawater. But if such a dune is breached, there is hardly any protection behind it. Natural dunes are wider and made up of countless smaller dunes. A single natural dune is therefore more vulnerable than an artificial dune, but all those dunes together provide strong protection. Above all, natural dunes are resilient: they can recover after a storm and grow along with rising sea level. Properties that are especially valuable in a changing climate.

Left: artificial dunes near Petten (Hondsbossche Dunes), right: natural dune formation on Texel (De Hors). Photo: Tom Kisjes.

4000 dune grass patches

Using aerial photographs and elevation models, Paul Berghuis, PhD candidate at Utrecht University and NIOZ, and colleagues tracked the development of a young, unmanaged dune landscape at De Hors, Texel. Berghuis: “We studied how more than 4000 dune grass patches formed a 12-hectare dune landscape over ten years. This shows that dune formation is determined by how patches are positioned relative to each other, while the size of the individual patch is of less importance.”

Capturing sand twice as efficiently

The analyses also reveal a clear tipping point: “Neighboring patches can already collaborate when the distance between them becomes less than 4.5 meters. The system then abruptly shifts from isolated sand traps to functionally connected groups.” That makes a big difference: “Within these groups, sand is captured and retained up to twice as efficiently, accelerating dune growth. Strikingly, dune grass only needs to cover a small fraction of the ground surface to build a large dune quickly.”

Left: dune grass patches trapping sand individually; right: dune grass patches that start trapping sand collectively. Photo: Tom Kisjes.

Useful for dune restoration

According to Berghuis, these new insights are useful for dune restoration. “By planting dune grass strategically, we can reach the tipping point for collaborate between patches sooner. That means we can build natural dune landscapes with relatively few plants and at lower cost.” Working with nature thus becomes a more attractive option: “The idea is simple: by planting strategically, we give dune formation a head start. After that, natural processes take over. In this way, we work together with nature to build resilient, future-proof dune landscapes.”

Publication

Paul Berghuis, Valerie Reijers, Johan van de Koppel, Angeles Mayor, Daniil Scheifes, Max Rietkerk, Tjisse van der Heide (2026), A connectivity threshold between grass patches amplifies coastal dune formation. Nature Communications. DOI: 10.1038/s41467-026-70552-7