As spring spreads across North America, trees, shrubs, and flowers release pollen. The male structures of flowering and cone-bearing plants produce this fine powdery substance. It fertilizes the female forms of plants when it is carried by wind, water, or pollinators.
about 25 million Americans are allergic to pollen. Pollen can trigger sneezing and coughing, as well as itchy eyes, a runny or blocked nose, and postnasal drainage. These are not welcome signs of spring. This collection of articles from our archive describes the latest findings on pollinators and how to cope with pollen season.
Hey pollinators! Over here
Pollen grains are essential for fertilizing plants because they carry the cells. For some plants, gravity or wind are enough, but pollinators must carry pollen grains. Some plants use nectar, edible pollen, or even tasty seeds to attract insects or bats, who then spread pollen as they feed. is used by many flowers to attract pollinators.
Thistle longhorned bees ( Melissodes Desponsa ) are covered in flower pollen. Dejen Mengis, USGS
Richard L. Harkess , a horticulturist at Mississippi State University, writes: “Floral scents are a mixture of many chemicals that float in the air and evaporate quickly.” Each species of flower emits a distinct scent to attract pollinators. Once pollinated, the flower will stop producing floral nectar or scents and instead direct its energy towards the fertilized embryo, which will eventually become a seed.
Read more: Why do flowers smell?
Bees at the buffet
Many species of insects have decreased in recent years. honeybees and bees of other species are two major focus areas. These pollinate important crops.
In a study from 2021, University of Florida agricultural specialist Hamutahl Cohen discovered that bees were more likely to pick up parasites when they visited fields with sunflowers being grown as crops. Bees that were able to choose between different types of flowers and forage in hedgerows surrounding crop fields had a lower rate of infection.
This California hedgerow has been shown to increase beneficial insects such as lady beetles and syrphid fly larvae that feed on aphids. UCANR, CC BY-ND
Cohen noted that the more bees present in sunflower fields, “the more parasites.” The sunflower blooms gathered bees and increased disease risk.
Read more: Planting mixes of flowers around farm fields helps keep bees healthy
Warmer weather means more pollen
Climate change is causing temperatures to rise across the U.S. Growing seasons start earlier and end later. Bad news for allergy sufferers.
The University of Michigan’s atmospheric scientists Yingxiao Zhang, and Allison L. Steiner explain that “the higher temperature will prolong the growing season giving plants more time for pollen to be produced and reproduction.” Climate change increases the amount of carbon dioxide in Earth’s atmosphere. This will allow plants to grow bigger and produce more pollen.
In the future, “Southeastern areas, including Florida Georgia and South Carolina can expect large increases in grass and weeds pollen.” Zhang and Steiner report that the Pacific Northwest will likely see a peak in pollen a month sooner due to an early alder pollen season.
Read more: Pollen season is getting longer and more intense with climate change – here’s what allergy sufferers can expect in the future
Providing better forecasts
How can allergy sufferers tell when pollen counts are high with all the pollen around? The U.S. only has a basic network of 90 pollen stations in the country. These are staffed by volunteers and only run during pollen season. This means that there is often no good information when people need it.
Fiona Lo is an environmental health researcher at the University of Washington. She and colleagues are developing a model to predict airborne releases of pollen. Lo reports that “our forecast can predict specific pollen types, because our model contains information about how different plant types interact with the environment.”
The model can only currently predict the levels of four common pollens in areas with observation stations. Lo and her colleagues “want to be able to give allergy patients the information they require to manage their symptoms every day, during pollen season.” The majority of allergy sufferers are unaware about how to manage their symptoms. A reliable pollen forecast, easily accessible via an app, along with information on managing allergies, would be a great help.
