Ahh chooo! Pine Pollen and Climate Change

 

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The bane of many a Southerner’s existence is springtime pollen. All that yellow dust swirling on the breeze and coating your car, that’s pine tree sperm.

The male cones of a Loblolly Pine (Pinus taeda) look like a bunch of tiny bananas growing from twig tips. If you’re thinking, “wait, that’s not a cone,” the woody cone we use to hot glue decorative wreaths or smear with peanut butter for DIY bird feeders is the female cone. Its spirals of woody shingles (or bracts) protect the tree’s eggs and, after fertilization, the developing pine embryos inside.

Male cones are much smaller and shorter lived. They release pollen for a couple of weeks each spring. And it’s a LOT of pollen: 3-5 pounds per tree. Why so much? Pines transfer pollen from male to female cones by wind. It’s not a very efficient system. More pollen increases the chance of fertilization.

With Climate Change, pollen’s gonna get worse. Ladeau and Clark (2006) found that pines growing in an elevated CO2 environment produce more pollen cones, and more pollen, at younger ages.

p.s. If you ever wondered what a pine pollen grain looks like, it’s a microscopic Mickey Mouse logo!

Ladeau SL, Clark JS. 2006. Pollen production by Pinus taeda growing in elevated atmospheric CO2. Functional Ecology. 20(3) 541-547.