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)…
Many aspects of climate change will not happen in a linear fashion. They will be quick and abrupt. Don’t imagine, say, getting out of shape from not running, but rather imagine: rupturing your ACL and not being able to walk. Yes, it’s that quick and abrupt with pollinator loss, or rare plants disappearing, or streams drying up. A stressed climate has many, many implications we will see only when they’re upon us. The wave is closing out, and we’re barely standing.
So where’s the human element? We stand the ability to be on guard and get set into action if we have a 3-year pine recruitment event. With stewards on the land and people willing to take to shovels and saws, we can retain open meadows and great habitat for a larger landscape. Is this a simplified scenario – yes – but this is often how simple conservation and restoration is: understanding the issue, monitoring it, and acting in a timely fashion.