Living in Berkeley is a surreal experience. Once the center of a political and social revolution, it’s now like wandering a graveyard that’s been infiltrated by high-tech picnickers. As you wander the streets you meet the ghosts of revolutions past, sometimes reformed into soccer grandmas with pressed silver hair and hand-hammered African jewelry, sometimes in the form of the homeless selling newspapers packing their lives into a few small bags, and sometimes as continued revolutionaries determined to ensure that the voice of their generation echoes through the streets everyday. And what are these new battles that must be fought? Is it police brutality in Oakland? Is it pervasive government spying? What about the closing of youth homeless shelters in the summer?
Well those are all well and good, but the revolutionaries of my town have bigger things in mind: sleep-ins against moving the post office (it *is* in a really nice building), legislative attempts to outlaw homelessness (sorry, I mean sitting on the streets), and most recently, a campaign to save the flammable and invasive Eucalyptus trees (“because they didn’t ask to be brought here” – actual quote).
So what’s my beef with eucalyptus? Actually nothing. With their colorful streaked bark and sweet medicinal smell, they provide a bucolic stroll through the Berkeley hills. They are alluring, hypnotizing, towering trees…but they also spread like wildfire…and spread wildfires… so they’re not great for a high fire area like California. But logic isn’t something that we’re used to using in my part of the Bay, and it comes out clearly when you try to figure out why a flammable tree native to Australia would have been planted in a high fire area in the first place.
What intrigues me isn’t the incredibly dishy local politics associated with the cutting of these trees; it’s how these fair trees will fare under climate change. In addition to being good fodder for local politics, eucalyptus are also a popular plantation species because they make rockin’ paper. So people everywhere are actually pretty interested in how these guys will respond to a warmer, more carbon-rich environment.
The thing is that plants often actually get used to new environments, changing their internal physiology when things get gradually warmer, or wetter, or whatever, to keep up their performance (i.e. keep photosynthesis chugging and all). This is referred to acclimatization, which is similar to the phenomenon of why you stopped asking your husband to pick up his socks after 35 years of marriage, and how I’ve gotten used to waiting 45 minutes for an avocado-sprout sandwich since moving to the Bay– we’ve both acclimatized to our new environments…I guess.
So if plants are these big acclimatizers, will eucalyptus follow suit, or go rogue? And as usual, it sort of depends. ‘On what?’ You ask. ‘The levels of carbon dioxide? The warming treatment?’
Well, sure, sure, yes those things are important, but actually so is the time of year. To everything, turn, turn, turn, there is a season…four of them really, and they interact with the local environment to impact plants.
You see, CO2 enhances photosynthesis in these plants year-round, but just a bit more in the summer. Meanwhile, a warmer treatment increased photosynthesis in the winter, but not in the summer—maybe they’re not the greatest acclimatizers when things get too hot?
So now we have an additional treatment to consider when thinking about how climate change will impact plant systems: temperature, CO2… and seasons? Great, that’ll make research that much easier. There is an upside, I suppose: a limitation to photosynthesis in hot, hot summers might actually keep the eucalyptus from taking off outside of its native range—more than it already has, I mean. This may add an interesting twist to the local politics in these here parts. Why worry about human intervention, when we could just wait for climate to restrict these plants for us?
One final note for all y’all out there who are still living in 1995 and think that climate change is great for plants because it’ll make them bigger and badder and all that, these plants that I’m talking about here are in plantations, where they are watered and fertilized and petted and loved and possibly danced around by moonlight. Unless you want to do that for every plant on earth (and please, don’t let me stop you), plants will typically run into some sort of other limitation outside of temperature or carbon dioxide…like nitrogen…or water…or someone with an axe. So y’know, keep the science in mind when you are blah blah blahing about this later tonight with your pals.
In the meantime, maybe climate change effects on the local forests will heat up the local politics in my part of the world. Or maybe not. We probably have bigger fish to fry; in fact I think I see someone trying to feed a homeless person. Do you have the number for the local cops?