Pines, Meadows and Climate Surprises – August Desktop Calendar

Erysimum capitatum ssp perenne-6654

Many high alpine meadows in the Sierra Nevada are undergoing conversion to lodgepole pine woodland and forest. These pines are grand and beautiful in many ways, but its the meadows that are risking extinction since they have little ability to equilibrate with the pines given reduced wildfires. These vast meadows that are critical habitat for wildlife and wildflowers alike are losing out to marching pines that seem to particularly invade (and become established) on excessively dry years (see John Helms’ 1987¬†Madrono¬†article).¬†Notably, as with many climate mediated change, the changes aren’t necessarily gradual. They occur at distinct moment (punctuated equilibrium), when a system will transition suddenly from one state to another: e.g. wet meadow with running water becoming mesic pine stand. A ticking timebomb if you will. Once the conditions are right, and all the seeds are in place, the pines get through a critical 3-year growth cycle and become established even if conditions return to a wetter cycle.

One notable implication occurs at the pollinator level. Bumblebees, bees, butterflies, and other pollinators typically have fewer flowers available in a closed canopy pine forest vs. an alpine wildflower meadow. Where will Pooh get his honey when the pines come marching in? I’m not sure, but I know that big meadows certainly are important for pollinator services. Basically, we could start to see quick losses in pollinator habitat at high elevation if meadows are congested with pines.

So what’s it all mean (big picture style)…

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