Funded by LBAYS: Vernal pools: Hotspots of biodiversity?

Charly Dixneuf, researcher at Lammi Biological Station, explored vernal pools in his 2020 master's thesis. These natural pools, with a unique water cycle, face less scrutiny than permanent wetlands despite threats like de-icing salt and climate change.

In January 2020, I started my master’s thesis at Lammi Biological Station (LBS) studying vernal pools and their roles in the enhancement of the vertebrate biodiversity. A vernal pool is a natural pool with a typical water cycle of filling and drying. One of the main consequences of human activity is biodiversity loss.

Loss of biodiversity in temporary wetlands, such as ephemeral pools, are much less studied than in permanent wetlands, ponds, and lakes. Vernal pools are threatened by water contamination due to road de-icing salt, ditching practices since the 1950s, and climate change. The aim of my study was to investigate the role of vernal pools for vertebrate communities by comparing the activity and species richness of birds and mammals between 10 ephemeral ponds, and 10 permanent wetlands.

Insights from fieldwork in Evo during winter and spring 2020

In order to carry out this study, my fieldwork has been done in Evo along winter and spring 2020, through bird sightings, camera trapping, faeces tracking, and snap-trapping.

Thanks to the fieldwork, I found out that bird’s activity depends on the season and the habitat. The results revealed higher activity in vernal pools in spring while in winter no differences have been observed between both habitats. Moreover, my results highlighted that the activity and species richness of large mammals were significantly higher by vernal pools than by permanent wetlands; and herbivorous mammals such as moose, roe deer and hare, seemed to visit more often vernal pools than permanent wetlands.

In the case of small mammals, despite no difference in abundance between both habitats, their activity changed monthly within the two habitats. In parallel, I conducted dissection of rodents to determine their age and their physical conditions (length, weight, body mass index etc.) but no differences have been found.

Those results demonstrated that vernal pools are providing high benefits to mammals and birds, which should be considered in forest management and in the context of climate change.

In July 2020 I graduated in my University in France and in the next year, the October 1st, 2021, a manuscript based on my research has been accepted for publication in the Global Ecology and Conservation Journal:

Spending the 6 months in LBS has been an amazing experience. I met fantastic people and I am very grateful for their help during my research. I want to thank the foundation for supporting my research. Charly Dixneuf is 2020 LBAYS grant recipient.

More research funded by LBAYS