Nature reserves alone can't reverse biodiversity loss


New research from Finland has shown that protected nature reserves do not always safeguard wildlife – often only decelerating species decline.

Protected nature areas – such as reserves – are deemed essential for maintaining biodiversity and countering its loss. However, research at the University of Helsinki shows mixed effects of protected areas on various species.

While protected areas have undoubtedly contributed to slowing the overall biodiversity loss, it is unclear how well they work across multiple species concurrently. To explore this, researchers at the university examined changes in the occurrence of hundreds of species within and outside of protected areas.

The research showed that nature reserves alone can not reverse species declines (Steve Oakes).

They discovered mixed effects, highlighting that protected areas do not fully meet the expectations set for them. Rather than reversing the trend in biodiversity loss, current protected areas will, at best, help decelerate the species decline rate. What they thus currently offer is more time to act on the root causes of biodiversity loss.

"Our results show that only a small proportion of species explicitly benefit from protection, but this varied by group. Birds show the highest positive response to protection, one out of five species, and plants show warm-dwelling species benefitting more. Protected areas mostly help by slowing down the decline of species occurrences," said associate professor Marjo Saastamoinen, senior author of the study.

"Our findings should not discourage us from establishing protected areas," commented Andrea Santangeli, lead author of the study. "Quite the contrary, they show that protected areas will buy us some time to counter rapid species loss. By protecting an area, we will slow the local loss of many species – but, at the same time, we cannot stop species loss by simply setting aside some small pieces of land here and there and expect miracles to happen."

For improving the effectiveness of protected areas, Dr Santangeli has a clear-cut recommendation: "What we need to do is to make the overall landscape more suitable for the species. Protected areas can serve as lifeboats, but in the longer run, these lifeboats will still need a safe landing site."



Santangeli, A, Weigel, B, Antão, L H, et al. 2023. Mixed effects of a national protected area network on terrestrial and freshwater biodiversity. Nature Communications. DOI: doi.org/10.1038/s41467-023-41073-4