Ten-year dataset provides vital clues to support Ireland's precious pollinators

Ecologists from Trinity College Dublin have discovered vital clues about how best to support Ireland’s precious pollinators after interrogating a decade-long dataset containing information from 119 sites across the country.

In general terms, the results confirm the importance of plant (and therefore flower) diversity in supporting an assortment of pollinator species, and while they highlight the invaluable role of bumblebees, they also shed light on the importance of ‘other species – with the hoverflies in particular more abundant as flower-visitors than might have been expected.

The dataset contains detailed data on plant-pollinator interactions from sites around Ireland, in all habitat types such as cultivated and built-up land; ribs; semi-natural and marshy meadows; hedges; and woods and brush.

It has grown and grown over the last decade through the work of Professor Jane Stout of Trinity and her collaborators, with much work coming from graduate students supported by the Environmental Protection Agency, the Irish Council for research, Trinity and European sources.

The six key points of the research, recently published in the journal Ecology and evolutionare:

• More flowers = more pollinating insects, regardless of habitat
• Flies are undervalued in their contributions; half of all flower-visiting species were hoverflies and these species account for over 33% of all visits
• Abundant and widespread flower types like bramble, white clover, knapweed and creeping buttercup are visited by many insects, but rare plants are important for rare pollinators
• Semi-natural grasslands are particularly important; they had the most pollinator species and the highest number of visits, and the communities were the most “distinct”, meaning they were different from other sites and contained the rarest species
• Bumblebees are an essential part of the pollinating fauna of Ireland
• Intensively managed habitats (urban, crops, and silage/dairy) have low pollinator diversity, despite the abundance of ornamental plants in urban sites

The researchers behind the work, led by Professor Stout and Laura Russo, now a professor of ecology and evolution at the University of Tennessee at Knoxville, hope these findings can be used to guide conservation practice. and land management in key areas.

Jane Stout, Vice President for Sustainability of Biodiversity and Climate Action and Professor of Botany at Trinity, said: “One of the most important findings of this work is that Ireland’s semi-natural grasslands are essential for the conservation of pollinators. This is because they support the most species, including the rarest species that are not found in better managed habitat types, and a higher proportion of threatened bee species. also lower proportions of non-native plant species, so they are also important for the conservation of native plants.

“Given that most of Ireland is covered in highly managed habitats, such as agricultural crops, silage and dairy pastures, as well as urban and suburban gardens and flowerbeds, it is of concern that these habitats had relatively fewer insect species.Urban habitats had more non-native plant species, which is not surprising given that most garden plants are not native to Ireland. this increase in non-native plant species does not correspond to an increase in insect diversity, so native plant diversity is returning to our highly managed habitats is important in supporting pollinator communities, and represents an action that thousands of us can take quite easily to help increase the number of pollinators.”

This work is part of the All-Ireland Pollinator Plan, which aims to provide food, shelter and security for bees and other pollinators in Ireland, so they can survive and thrive.