Another record from Park City’s urban forest!

Complaining about our urban forest getting out of control has become a recurrent subject. If we needed to be reminded about it, this year’s record setting pollen is one very valid reason! It’s a fact that evergreen trees don’t necessarily shed the same quantity of pollen every year. 

Their pollen production varies due to a bunch of environmental and biological factors, like the warmer spring we just had in the Rocky Mountains that has caused more pollen production. Our windy conditions have done their part by dispersing it much more effectively than usual. The situation is also exacerbated by trees planted 40 to 50 years ago that now produce more pollen as they’re reaching maturity. 

Pollen production varies also from year to year as many spruce species show synchronized, intermittent years of high pollen and seed production, followed by lower-output years. Quite obviously, this is a record breaking year! Our mild winter has seen evergreens pollinating earlier and more intensely than ever before. Higher atmospheric CO₂ may have also played a role in increasing their production.

Our pollen covered deck at the end of May

Finally, I’ve always asked myself if pollen production was sex-oriented, and I found out that evergreens like pines, spruces or firs produce both pollen and seeds on the same tree, but in separate structures (male cones vs. female cones). For instance, male cones (small, often clustered) do release pollen, while female cones (larger, woody) just develop seeds after pollination. 

Now that I’ve learned all that stuff and shared it with you, will you give me a hand cleaning my deck when I’ll get to doing it around the middle of June?