In Ant-icipation of Restoring Soil Health

Publish Date: Thursday December 19, 2024

Biodiversity Conservationist, Gabrielle Flinn, tells us about her project to find out if Yellow meadow ants can restore grassland habitats.

Europe has witnessed the rapid loss of 90% of semi-natural grasslands. And this large-scale loss is echoed across landscapes around the world.

Grasslands are important for fighting climate change, being more efficient and reliable in carbon storage than forests (Dass et al. 2018). They are also important for wildlife, and the loss of this habitat has significantly affected groups such as pollinators.

There is an urgency to protect and restore grassland habitats because they can help to build our climate and biodiversity resilience in the face of multiple crises.

The Bumblebee meadow at RSPB Loch Leven is a piece of former agricultural land converted into a species-rich grassland for pollinators. Lochore Meadows Country Park has some of Fife’s most ancient grassland and a very healthy and abundant population of Yellow meadow ants.

Research questions

I am undertaking PhD research at these two sites to answer the following:

1. Do Yellow meadow ant (Lasius flavus) mounds provide important resources for pollinators?
2. How do Yellow meadow ants affect the restoration of grasslands undergoing restoration?

To answer the first, I have been roaming the meadows of the National Trust Belton House Estate in Lincolnshire, and Lochore Meadows in my native Fife. This spring and summer I spent many days (in quite astonishingly variable weather conditions) counting flowers, taking temperatures and watching mounds (for a total of 27 hours).

Thanks to Elena Marco Pardo, Steven McGee-Callendar and Alexandra Koulouris for helping. Early signs point to a promising pattern of increased flora, temperature and bare ground availability on mounds compared to normal grassland. However, now the serious part begins, the analysis to reveal the truth.

Impact

To answer the second question, we needed to identify a grassland undergoing restoration that did not yet have Yellow meadow ants present – so that we could introduce the species and observe its impact. My good friend James Silvey told me about the Bumblebee meadow at RSPB Loch Leven and that it might be a good candidate for translocation.

While Yellow meadow ants are widespread and common, they’re not found nesting on ploughed land because of ploughing’s destructive nature. The Bumblebee meadow used to be agricultural land and was likely ploughed in the past. Before translocation, we surveyed which ant species were already present. We didn’t detect the presence of any ant species, and all the mounds we found were mole hills – giving us our first green light.

Once relevant approval was gained and volunteers were located (thank you very much RSPB Scotland, FCCT and a local youth employability group), it was time to go.

Movement of Yellow meadow ant mounds

In March 2024, before the ants are too active and after the ground has thawed, we dug up and moved eight Yellow meadow ant mounds from Lochore Meadows to the Bumblebee meadow.

Because these ant nests existed in ancient grassland, they were a lot larger and more extensive than we realised. Many intricate and beautifully carved-out tunnels were found within. We did our best to limit the damage to the mounds, but also to ensure the entirety of the colony was translocated – including the all-important egg-laying queen who gives purpose and life to the colony.

We also moved big chunks of ant-free turf to make fake ant mounds to see if, in two years’ time, the ants are making the change, or is it just the introduction of something new?

In summer I visited the translocated mounds in their new home. With ecstasy and relief, I discovered that not only were all the colonies active, but they were so healthy that they were churning out the next generation of flying ants (who will go on to reproduce and form new colonies). This is a brilliant sign that not only the colonies are surviving, but also thriving – a testament to the ants’ resilience, considering the turmoil they went through.

Yellow meadow ant colonies have been successfully translocated before (King and Balfour, 2019; Box, 1987; Pontin, 1969), but the consequences of this translocation, particularly on the restoration process, have not yet been investigated. It’s thrilling to have the opportunity to take a closer look at the role that ants play and perhaps illuminate whether their inclusion in grassland restoration initiatives is key.

What happens in the future

We’ll return in 2025 and 2026 to examine if and how the plant and pollinator communities have changed. We will also take soil samples to investigate how bacterial and fungal life have changed in the hopes of better understanding how ants impact the restoration of soil health.

Can ecological surgery of ant mounds help to restore grassland habitats? We wait in ant-icipation.

Read the full version of Gabrielle’s blog.

This project is a partnership between the University of York, UKCEH, RSPB Scotland, Fife Coast and Countryside Trust and the National Trust. It is funded by the John Lewis Partnership Foundation.