Pining for Carbon

Conifers_landin

The boreal forest, or taiga, extends across Canada and Russia. Conifers dominate this cold ecosystem. The evergreen needles allow the trees to photosynthesize all year.

While conifers grow well in the frigid taiga, they don’t decompose very quickly when a tree falls. In other habitats, trees that die release their carbon as they decay. The pines, firs, spruce, and larches of the taiga soak in carbon from the atmosphere, add that carbon to their mass, and hold it in their bodies even after they die. One study suggests that the boreal forest sequesters twice as much carbon as tropical forests and six times the amount held in temperate forests (1).

For now, the taiga is helping us combat climate change. As temperatures warm, though, stored carbon can break down and release into the atmosphere as carbon dioxide, exacerbating the issue. The more we limit carbon emissions now, the more the boreal forest can help us into the future.

  1. https://www.borealbirds.org/sites/default/files/pubs/report-execsummary.pdf

Ahh chooo! Pine Pollen and Climate Change

 

pine_malecones2 copy

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.