Busy times for pollen expert

A quick glance at her office shows that this is a researcher’s domain. The walls are lined with books, bound journals and folders of teaching materials.

“It’s safer to store it here than in my head,” explains Åslög Dahl.

A microscope stands on her desk, and the table is covered with potted plants and notebooks. But what really stands out is an enquiring pair of cat’s eyes peeping above spectacles and a newspaper. It may only be a framed picture, but the cat looks eerily alive.

“I’ve loved cats since I was first able to say ‘meow’. I have three of them, Sofus, Tissle and Lilla Psi, and I grew up in a family of cat lovers.’

Åslög was brought up in a spacious but run-down apartment in a house dating from the 1890s in the Heden district of Gothenburg. Her father was a professor of cultural geography, and her mother was a genealogist who studied Gothenburg’s 17th and 18th century landowners. Her grandfather was a director of the Alnarp estate, and she and her siblings all became researchers. As a girl, she had vague plans to go into journalism, and then into medicine, before eventually studying chemistry and biology. The year was now 1975, and Åslög was 20 years old.

Her bachelor’s degree led to research studies on the Hypecoum, a member of the poppy family.

“At that time, little thought was given to gender equality in academia. But I was one of three girls to be accepted for doctoral studies at the same time.”

At the University of Gothenburg, she was inspired by Senior Lecturer in Botany Sven-Olov Strandhede.

“He probably also struck a chord from my childhood and my grandfather, as I decided to continue studying botany.”

Strandhede, who became her mentor, saw the need for botanical knowledge within allergy care, and founded the Pollen Laboratory in 1975. The laboratory analyses airborne pollen, issues forecasts and provides society with information about pollen. When Strandhede retired in 1997, Åslög assumed responsibility for the laboratory which was then transferred to the research company Botanical Analysis Group. She remained CEO until 2006.

“In 2012, the laboratory came back under the management of the university. I came too, but remained on a ten percent basis as Head of Research for the company, which now analyses mould and rot samples. There, I deal with issues involving mould and its effect on the indoor environment.”

Over the years, her research has revolved around factors relating to blooming, the amount of pollen from birches and other plants, and links to allergies. Today, between 20 and 25 percent of the Swedish population are hypersensitive to pollen. Åslög works with doctors on studies of how the immune defence reacts to pollen.

“The type and amount of pollen, and when blooming occurs – it all affects allergy symptoms.”

Climate change also means that the pollen season is starting earlier and ending later.

“Improved hygiene has resulted in young children’s immune defences not maturing in the same way as they once did. And because they now spend less time outdoors, they often don’t come into contact with plants and animals at an early age. This exposure is important for developing tolerance to natural substances.”

Over the years, the pollen laboratory has gathered various time series of pollen data from around forty locations in western Sweden. These clearly show the effect of the climate on plants.

Åslög’s research is spread across two fields. One is phenology: how nature changes over the seasons and the periodical phenomena within the plant kingdom. She co-founded the Swedish National Phenology Network, within which botanical gardens, nature centres, government agencies and amateurs make observations. So far, the network has gathered 150,000 observations.

“The idea is to include our data in the Swedish Species Information Centre’s databank. Data from 1823 to 1926 can also be compared, giving indicators for how plants are affected by climate changes.”

Her other research field involves bees and what they gather. Pollen is their only source of protein. She has spent 20 years analysing pollen in honey, and has also given courses for beekeepers. A new research project in collaboration with Swedish and Norwegian partners will involve her comparing domestic subspecies of honey bee with the southern European subspecies imported into the Nordic region during the mid-20th century.

“The Nordic bees are less productive, but they are well suited to the local flora and climate.”

Åslög has remained interested in botany and evolution over the years.

“The geneticist Theodosius Dobzhansky said that nothing in biology makes sense except in the light of evolution. At that’s very true.”