Protected areas and other conservation policies are essential tools for reducing human pressure on species. But none of these measures alone will be enough to halt biodiversity loss. Instead, the entire agricultural and forestry production system would need to be transformed, among other measures. This is the main conclusion of a study published in Nature Ecology & Evolution, led by INRAE and CESAB in France and involving CREAF, CSIC, the Catalan Ornithological Institute and the Granollers Museum of Natural Sciences. The study analyses population trends in 265 bird species and 144 common butterfly species in Europe between 2000 and 2021 and projects how their populations could change by 2050 under four conservation scenarios, taking into account the effects of climate change, land use and the intensity with which land is managed — for example, whether forests are harvested more or less intensively or whether agriculture is more or less intensive. The results show that even under the most ambitious scenarios, which include additional conservation measures such as the EU Biodiversity Strategy for 2030 and the European Green Deal, populations would continue to decline.
Most studies project what will happen if we continue as we are or under the most pessimistic scenarios. In line with international initiatives, we wanted to answer a different question: are more nature-positive conservation policies enough to restore biodiversity in Europe? Unfortunately, none of the scenarios analysed succeeds in halting or reversing the overall decline in populations of common birds and butterflies
Lluis Brotons, CREAF researcher and co-author of the study
According to the authors, this is largely because pressure on land remains high. “One of the most determining factors is that the intensity of land use continues to increase. For example, the use of forests for logging is expected to become more intensive in Europe under all the scenarios analysed. The same applies to agriculture. This could have a negative impact on the biodiversity of common birds and butterflies, despite conservation efforts,” explains Tristan Bakx, CREAF researcher and co-author of the study.
Moreover, the effects of the different scenarios are not the same across the continent. In Spain and southern Europe, for example, an increase in intensive agricultural management is projected under all the scenarios analysed. This increase in productivity would affect populations of common birds and butterflies, which would continue to decline. This pressure is compounded by a more pronounced impact of climate change in these regions, further exacerbating the decline of many species.
YOU MAY ALSO BE INTERESTED IN
Farmland birds and butterflies among the hardest hit
The study once again identifies intensive agriculture as one of the main drivers of the decline of common birds and butterflies in Europe. In particular, the expansion of monocultures, intensive use of pesticides and fertilisers, and landscape simplification continue to have a particularly negative impact on farmland birds and meadow butterflies.
Secondly, the study highlights that forest cover has expanded in recent years, mainly because of rural abandonment. These extensive and uniform forests, which are predominant in Catalonia and elsewhere in Spain, are low-quality habitats because they support very low species diversity. As a result, they are less suitable for specialist forest birds and for butterflies, which need open spaces within forests. Traditional management systems favoured a dynamic landscape mosaic, with the creation of small clearings. However, future scenarios envisage an increase in intensively managed forests for logging alongside conservation policies, which could further limit forest biodiversity.
Many forest bird and butterfly species need more diverse forests, with clearings, open spaces and different vegetation structures — habitats that are tending to disappear both as a result of rural abandonment and intensive forest management.
Tristan Bakx, CREAF researcher and co-author of the study
Finally, there is climate change. While birds have so far shown a more heterogeneous response to global warming — some species will benefit while others will not — butterflies are expected to be more strongly affected by rising temperatures and changes in rainfall patterns.
Four future scenarios
To reach this conclusion, the research team explored four scenarios through to 2050 in which conservation actions are implemented across Europe. The first envisages a transition towards a more sustainable development model, while the other three incorporate nature-positive approaches and even more ambitious conservation targets, aligned with the EU Biodiversity Strategy for 2030 and the European Green Deal. The measures include expanding protected areas to cover 30% of the territory, restoring degraded ecosystems, reducing the use of nitrogen fertilisers, increasing natural areas, and promoting more sustainable agricultural and forestry practices.
To develop these scenarios, the researchers used the Nature Futures Framework (NFF), the conceptual framework developed to explore possible futures for nature by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). This tool makes it possible to identify potential socio-environmental futures from a nature-centred perspective. Its application allows researchers to estimate how biodiversity could evolve depending on different decisions concerning climate, land use — for example, how much land is allocated to forests, crops or natural areas — and the intensity with which land is managed, that is, whether agriculture and forestry are carried out more or less intensively.
“Although some conservation actions succeed in slowing the decline of several populations, particularly those of bird and butterfly species associated with open habitats, none of the scenarios analysed succeeds in reversing the overall decline,” the research team emphasises.
Metropolitan butterflies decline by more than 30% during drought. Image: Pau Guzman
We need conservation policies, but not only conservation policies
The results show that expanding protected areas or implementing targeted conservation measures will not be enough unless they are accompanied by a deeper and broader transformation of agricultural systems and land management. “It is important to bear in mind that the models and scenarios used assess current land uses, which we know can have major negative impacts on biodiversity. New strategies for agricultural production and logging, together with even stronger climate change mitigation, are likely to be needed to change the situation,” says Bakx.
The study makes it possible to anticipate the effects of environmental policies on common biodiversity in Europe and provides key information to guide future European conservation strategies in a context shaped by climate change and growing demand for natural resources.
The study was led by the French National Research Institute for Agriculture, Food and Environment (INRAE). It also involved Spanish institutions including CREAF, CSIC, the Catalan Ornithological Institute and the Granollers Museum of Natural Sciences, among other European organisations. Sergi Herrando, a CREAF researcher and researcher at the Catalan Ornithological Institute (ICO), as well as president of the European Bird Census Council (EBCC), also participated in the study. The research was supported by the European BioAgora project, funded by the Horizon Europe programme.
This work was made possible thanks to the year-round participation of many volunteers involved in bird and butterfly monitoring programmes coordinated by the European Bird Census Council (EBCC) and Butterfly Conservation Europe (BCE). In Catalonia, these programmes are coordinated by the Catalan Ornithological Institute and the Catalan Ornithological Institute Beta.
Reference: Rigal, S., Lenormand, M., Tardieu, L., Alonso, H., Auniņš, A., Bakx, T. R. M., Boom, M. P., Brambilla, M., Brotons, L., Chodkiewicz, T., Fontaine, B., Faltynek Fric, Z., Gamero, A., Herrando, S., Kålås, J. A., Kamp, J., Kurlavičius, P., Kuussaari, M., Lehikoinen, A., Maes, D., Mestdagh, X., Musche, M., Øien, I. J., Pettersson, L. B., Reif, J., Rüdisser, J., Šašić, M., Schmucki, R., Settele, J., Stefanescu, C., Stokke, B. G., Strebel, N., Titeux, N., Trautmann, S., Van Swaay, C., & Luque, S. (2026). Predicted decline in common bird and butterfly species despite conservation policy scenarios in Europe. Nature Ecology & Evolution. https://doi.org/10.1038/s41559-026-03139-6
