Trees, shrubs and flowers unravel as spring expands across North America pollen. This fine, powdery substance is produced by the male structures of cone-bearing and flowering plants. Fertilization occurs when it is carried into the female structures of plants by wind, water or pollinators.
As pollen travels, it also triggers allergies. about 25 million Americans. Pollen exposure can cause sneezing, coughing, itchy eyes, runny nose and postnasal drip – these are undesirable signs of spring for patients. These articles in our archives describe the latest findings on protecting pollinators and coping with the pollen season.
1. Hey pollinators, here
Because pollen grains carry the cells that fertilize the plants, it is very important for them to get where they need to go. Often wind or gravity is sufficient, but for many plants a pollinator has to carry the pollen grains. Some plants offer nectar or edible pollen to attract insects, bats, or other animals that carry the pollen from plant to plant. Also many flowers lure pollinators with scent.
A thistle longhorn bee (Melissodes desponsa) covered with flower pollen.
Dejen Mengis, USGS
“Similar to perfumes on a store counter, floral fragrances are made up of many and varied chemicals that readily evaporate and float in the air,” writes the Mississippi State University horticulturalist. Richard L. Harkess. “To distinguish itself from other flowers, the flowers of each species emit a unique scent to attract certain pollinators. … After pollination, the flower stops producing floral fragrance and nectar and directs its energy to the fertilized embryo that will become the seed.”
2. The bees at the buffet
In a 2021 study, University of Florida agricultural extension specialist Hamutahl Cohen When bees visit fields where crop sunflowers are blooming on many acres, received high parasites. In contrast, bees that foraged on hedges around crop fields and were able to choose to feed on a variety of flower species spread farther and had lower infection rates.
Hedges like this one in California have been shown to increase the number of beneficial insects such as ladybugs (left to right), squirrel flies and their larvae, which have been shown to feed on aphids.
UCANR, CC BY-ND
“The more bees there are in the sunflower fields, the more parasites,” Cohen observed. “Sunflower flowers were attracting bees, which increased the risk of disease.” However, “in the presence of many flower species, the bees disperse and spread to the sources, making each bee less likely to encounter an infected individual.”
3. Warmer air means more pollen
As climate change raises average temperatures across the United States, growing seasons begin earlier and end later in the year. This bad news for allergy sufferers.
“Higher temperature will extend the growing season and give plants more time to pollinate and reproduce,” say atmospheric scientists from the University of Michigan. Yingxiao Zhang and Allison L. Steiner. And climate change will increase the concentration of carbon dioxide in the Earth’s atmosphere, making it possible for plants to grow more and produce more pollen.
“Southeastern regions, including Florida, Georgia, and South Carolina, can expect increased largegrass and weed pollen in the future. In the Pacific Northwest, alder alder is likely to see peak pollen season a month earlier, due to an early pollen season,” Zhang and Steiner said.
4. Providing better forecasts
With all the pollen out there, how do allergy sufferers know when the numbers are high? The USA today has only a rudimentary network of 90 pollen monitoring stations around the country, made up of volunteers and operating only during the pollen season, so often the good information people need is simply not available.
Fiona LoAn environmental health scientist at the University of Washington is working with colleagues to develop a model that can predict airborne pollen releases. “Our prediction can predict certain types of pollen, because our model includes insights into how each plant species interacts with the environment differently,” Lo said.
So far, the model predicts only four types of common pollen levels in areas where observation stations are located. Ultimately, however, Lo and collaborators want to “provide a forecast every day during the pollen season and give allergy sufferers the information they need to manage their symptoms. Allergies are often poorly treated and information on self-care is limited, so for example, via an app on your phone.” A reliable pollen forecast that is easy to access can really help allergy sufferers as well as education in allergy management.”
5. Support the pollinators in your garden
Pollen season is also garden season as the plants bloom. West Virginia University mycologist Brian Lovett Offers advice for aspiring gardeners. attract beneficial insects to their garden for pollination and other purposes.
One step is to replace the grass with native wildflowers, which will provide pollen and nectar for insects like ants, bees and butterflies. “Just as you might have a favorite local restaurant, the bugs that live in your neighborhood are fond of native flowers,” Lovett says.
Replacing white bulbs with yellow or warm colored LED bulbs and providing water in dishes or other containers are also insect-friendly steps. Local university expansion offices and horticultural stores may offer other suggestions.
“To me, people often see ourselves as separate from nature, which leads us to refer to biodiversity designated parks,” Lovett says. “In fact, we are an important part of the natural world, and we need insects as much as they need us.”
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