Not just meadows and pastures – arable fields can also support rich biodiversity

A research team led by the Swedish University of Agricultural Sciences (SLU) found that oilseed rape fields can be far richer in plants and insects than previously thought.

“We were surprised to find that the number of species characteristic of oilseed rape fields was almost as high as in permanent grasslands,” says Fabian Bötzl, lead author of the study, which was recently published in Nature Communications.

From Sweden to Bulgaria

The researchers studied biodiversity in 86 permanent grasslands and nearby oilseed rape fields across Sweden, Germany, Switzerland, Romania and Bulgaria.

They focused on four important groups of organisms – plants, butterflies, wild bees and ground beetles – to understand how different habitats shape biodiversity. They also investigated whether a greater proportion of permanent grasslands in the surrounding landscape could promote biodiversity and facilitate the spillover of grassland-associated species into nearby oilseed rape fields.

Butterflies, wild bees, ground beetles and plants

In total, the researchers recorded 325 plant species, 78 butterfly species, 195 wild bee species and 239 ground beetle species.

Permanent grasslands supported substantially more plant and butterfly species than oilseed rape fields. However, oilseed rape fields hosted as many – or even more – species of wild bees and ground beetles.

The species assemblages also differed markedly between the two habitat types. Overall, 82 species were associated with permanent grasslands, while 63 species were associated with oilseed rape fields.

The results further showed that habitat type – whether a site was a grassland or an oilseed rape field – had a greater influence on biodiversity than the amount of grassland in the surrounding landscape.

“That was also somewhat unexpected. Our hypothesis was that landscapes with more permanent grassland would support a larger regional species pool and therefore more species in both individual grasslands and oilseed rape fields,” says Erik Öckinger, researcher at the Department of Ecology, SLU.

Oilseed rape fields and other crops

The study focused on oilseed rape fields, and further research is needed to understand how other crop types contribute to biodiversity. Nevertheless, cereal fields and other arable crops can also be managed in ways that support wildlife.

“The results for wild bees would almost certainly have been different if we had studied wheat fields instead of oilseed rape, although this may not have been the case for ground beetles,” says Erik Öckinger.

The hidden biodiversity of arable land

One of the study’s most important findings is that both permanent grasslands and arable fields harbour species-rich and distinct communities of organisms. Together, they contribute more to regional biodiversity than either habitat type does on its own.

“Our study shows that conserving biodiversity in agricultural landscapes is not only about protecting permanent grasslands. It is also important to manage arable land in ways that benefit plants and animals,” says Ola Lundin, researcher at the Department of Crop Production Ecology, SLU.

This includes increasing diversity in crops and crop varieties, both over time within fields and across farms in the landscape. Reduced use of plant protection products, less intensive soil cultivation and the use of organic fertilisers can also benefit wild species. Field size matters as well – smaller fields create more habitats for wild plants and insects.

Scientific article

Fabian Boetzl, Giovanni Tamburini, Cristina Craioveanu, Andrei Crișan, Toshko Ljubomirov, Vlada Peneva, Laszlo Rakosy, Georg Rieland, Josef Settele, Anja Schmidt, Oliver Schweiger, Teodora Teofilova, Natalia Timuş, Martin Wiemers, Niklaus Zimmermann, Boyan Zlatkov, Ola Lundin, and Erik Öckinger, 2026. Crop fields complement biodiversity in permanent grasslands across European landscapes. Nature Communications