New study shows functional diversity key in bird community resilience to climate change

The mourning dove is a habitat generalist. (Image: Aleksi Lehikoinen)

(PRESS RELEASE) HELSINKI, 17-Jan-2023 — /EuropaWire/ — University of Helsinki, the oldest and largest institution of academic education in Finland, has announced that a new study has revealed that biodiversity may play a crucial role in safeguarding bird communities under a changing climate. The study, which covered nearly all North American bird species, found that bird communities containing functionally diverse species have changed less under climate change during the past 50 years than functionally simple communities.

Climate change has a significant impact on ecosystems and ecological community compositions, but the reason certain communities are better able to resist the effects of climate change than others has remained unclear. The study aimed to shed light on this question by examining community composition changes and community diversity over a period of 50 years. The researchers found that consistently, bird communities with higher species richness and a larger variety of functional properties changed less dramatically in their community composition following climate change.

The study provides important insights into the impact of climate change on bird communities and the role that biodiversity can play in protecting them. It suggests that conservation efforts should focus on preserving the functional diversity of bird communities in order to ensure their resilience to climate change.

“For example, if a community contained birds of prey, insectivores, and seed-eaters rather than birds from just one feeding guild, it was better safeguarded against the negative impacts of climate change,” highlights PhD Emma-Liina Marjakangas, the leading researcher of the study from University of Helsinki.

Community-level diversity works as a buffer against negative climate change impacts, especially during winter, i.e the season that has shown strongest climatic warming across the Northern Hemisphere. On the other hand, biodiversity played a smaller role during the breeding season. Indeed, earlier studies have shown that bird communities change faster during winter than summer, which explains this pattern.

“Habitat and available food determine a species’ flexibility for changing its breeding and wintering areas. For example, grassland species have shifted their distributions northwards slower than forest passerines, such as the American robin, or habitat generalists, such as the mourning dove,” explains Senior curator Aleksi Lehikoinen from the University of Helsinki.

Functionally diverse bird communities help maintain ecosystems via plant seed dispersal, pest insect control and even pollination of flowering plants. Climate change reshuffles the composition of these important bird communities and therefore threatens their ability to provide ecosystem services.

“Our results strengthen the understanding that biodiversity safeguards ecosystem functioning and that the biodiversity and climate crises need to be mitigated simultaneously to avoid multiplicative effects,” Marjakangas emphasizes.

The study is based on a community science database from 1966–2016 covering all of North America, and it was published in the international journal Scientific Reports.

Original publication

Marjakangas, EL., Santangeli, A., Johnston, A. et al. Effects of diversity on thermal niche variation in bird communities under climate change. Sci Rep 12, 21810 (2022). https://doi.org/10.1038/s41598-022-26248-1

Media contacts:

Emma-Liina Marjakangas
Postdoctoral researcher
ZOOLOGY
emma.marjakangas@helsinki.fi

Aleksi Lehikoinen
Senior Curator
ZOOLOGY
aleksi.lehikoinen@helsinki.fi
0294128851

SOURCE: University of Helsinki