When it comes to trees, the springtime adage ”love is in the air” takes on a whole new meaning. Each year, after the first week of warm weather, juniper trees take the first step in their reproductive dance by releasing sperm, held in the center of pollen grains.

To allergy sufferers, that dance is anything but romantic.

Allergy season officially arrived in Central Oregon nearly two weeks ago, according to local allergists. That’s when juniper pollen – the first of Mother Nature’s arsenal of seasonal allergens – took to the air.

”The juniper season in Bend is legendary,” said Dr. Mark O’Hollaren, director of the Allergy Clinic in Portland.

O’Hollaren and other doctors are hesitant to predict how severe this year’s season will be.

”It’s extremely difficult to predict because it involves successfully predicting the weather,” O’Hollaren said. ”And there are meteorologists who have gone through years of training and have special equipment for that, and even they have trouble. And so allergists have an even harder time.”

Allergies are mainly genetic, affecting about 15 percent of the population, said Dr. Joel Depper, an allergist in Bend.

An allergy occurs when a person’s immune system is abnormally sensitive to an ordinarily harmless substance. When an allergen enters the body of an allergic person, the immune system reacts by treating the substance like a harmful invader.

The body releases large amounts of a substance called histamine, which causes allergy symptoms like itching, sneezing, watery eyes, a runny nose and, in some cases, fever or fatigue.

”A common cold can give you some of these symptoms, but you probably won’t itch if you have a cold,” Depper said. ”Itching is one of the most important keys to hay fever.”

Although they have nothing to do with hay, allergy symptoms are often called ”hay fever” because in the eastern half of the country, they tend to flare up in late summer, or haying season, Depper said.

More than 36 million Americans suffer from hay fever, according to a 1997 study in the Journal of Allergy and Clinical Immunology.

Trees and grasses, unlike flowers, rely on wind to pollenate, so they produce powdery pollen that is easily inhaled, and often triggers allergic reactions.

In Central Oregon, allergenic pollens hit the air one at a time in tight succession, Depper said.

Juniper season should end by the beginning of May, at which point pine trees will start to pollenate. In June and July, grass pollen will take flight. Then weeds begin to pollenate, with rabbit brush in August and sage brush for the two months following that, according to Depper.

”It’s a very simple place,” he said. ”Over in the Willamette Valley, where it doesn’t freeze like it does here, the allergy season is much more complicated.”

From October to March, the air in Central Oregon is pollen-free, Depper added.

”Bend, in general, is a good place to live,” he said. ”But juniper can be very intense for people with allergies … certain plants cause particularly intense reactions, and juniper is just one of those plants.”

Allergists keep track of pollen cycles using machines that regularly inhale air samples.

Depper, for example, keeps a machine in Tumalo.

”It sucks in air for 10 minutes, four times a day. And it puts all of the particles from the air on a slide,” he said.

Depper then counts the number of pollen grains on each slide, under a microscope.

A pollen count gives the number of particles in a cubic millimeter of air in one minute, Depper said. The higher the pollen count, the more likely it is that people will have allergic reactions.

Pollen counts vary depending on a machine’s location and the time of day it collects its samples. Readings are highest in the morning, Depper said. Scientists are not exactly sure why that is.

Allergists have different opinions on what constitutes a high pollen count.

Depper, for example, said he considers a pollen count over 600 to be high.

Local juniper pollen counts have approached 1,000 in the past week.

Grains of pollen are coated with tiny ”recognition proteins” that dissolve easily in moisture. If a juniper grain, for example, successfully reaches the female counterpart of a juniper tree, these proteins help the parts recognize each other and begin the fertilization process.

”Pollen grains are moved in the wind, and when they end up getting sidetracked in our nose or our eyes, they don’t know that we’re not a plant,” O’Hollaren said. ”So those little recognition proteins dissolve in the moisture on our nose or in our eyes. And those proteins are what cause reactions.”

”Certain people react to one protein and not another. And we’re not completely sure why that’s the case,” he said.

What scientists do know is that a single juniper tree releases billions of pollen grains into the air each season, so breathing pollen this time of year is unavoidable.

People with allergies, Depper said, ”can go to Mount Bachelor and get away from it. Above 4,500 feet, there are no Juniper trees.”

Short of moving, there are steps people can take to control their allergies. Over-the-counter medications are often effective in controlling allergy symptoms, doctors said.

Non-drowsy medications like Claritin are preferable, O’Hollaren said, because they are less likely to impair driving ability.

If these medications are not controlling allergies, it might be time to visit an allergist.

Prescription nasal sprays and eye drops are safe and effective options a doctor could provide, he said.

Certain symptoms should make anyone call their doctor.

”If they get short of breath or develop chest tightness or wheezing,” he said, ”then they may have some asthma symptoms and they should not treat that themselves, they should go see their doctor.”

Lily Raff can be reached at 541-617-7836 or lraff@bendbulletin.com.