(continued…)
I’m also not sure we really understand where we live. I am sure we don’t have any idea what the side-effects of what we do really are, especially considering where we live on the edge of the Pacific Ocean.
Looking at the tree growth ring records in California, it’s clear that this land has had more than a few droughts over the past millennium. One lasted from 892 to 1112 (120 years), another from 1209 to 1350 (141 years). Judging by how far water levels dropped during these periods -- as much as 50 feet in some cases -- these droughts were not only much longer, they were far more severe than either the drought of the 1930s or the short dryness of 1987 to 1992. And yet we’ve built cityscapes that requires nearly ALL of the free water in the state to be dedicated to agriculture and city uses. As you can see in the Owens Valley, even the aquifers of “old water” (that’s taken millennia to accumulate) have been drawn down by 30 feet or more. We won't know if today's drought in California will equal the historic droughts, and we won't know for another 100 years.
What happens if, or when, we re-enter another century-long drought? We’ve already greatly disrupted the ecology of California, putting much of what we consider “normal” at risk. The same is true for Arizona, New Mexico, Texas and the southwest in general. Texas is burning under this year’s drought, which also brought the biggest cotton crop failure ever in the US. Surprisingly, cotton markets reacted almost not at all because other cotton producers had their largest crops ever, handily filling the void caused by Texas’ failure. The cotton fiber market got lucky. Globally, it all evened out. But it seems like luck.
Yet we seem to have built-out so much of our urban/suburban spaces that when the next long, normal, expected drought happens, that’s when the unintended consequences of expansionism will become clear. Remember the story of the Vikings in Greenland—they colonized it during a period of extended warmth. When the normal wintery conditions returned, they couldn’t adapt, and fell back (or died-back) to Scandinavia. That option isn’t exactly available to the people of California.
That’s also not an option for the frogs. And here’s the thing: It’s not clear why this sudden global death in the clade is happening now. Was it something that we did? Perhaps something released by accident into the global environment (such as estrogenic compounds, heavy metals, or organic solvents)? Or is this frog fungus just particularly virulent as a result of cross-breeding with an accidental import from another continent? The big scare about the frog die-off is that it’s not just being unlucky, it’s potentially a major catastrophe. Frogs are keystone species in many habitats; they’re not just expendable. You don't wipe out a keystone species without a big piece of the architecture falling down around you.
But all is not lost.
A really interesting experiment in restoration took place recently. In their article “Ecological rebound on Phillips Island” (Ecological Management Restoration, 2010, v 11, n 1, pp: 4-15) Peter Coyne tells the story of Phillips Island in the South Pacific. Pigs were introduced to the island in 1793 by passing sailors; then goats and rabbits were added in 1830 leading to the island being described as nothing but “bare red earth” by 1856. In 60 years the island went from a viable, albeit small, ecology to zero. The introduced species ate the island to death. Eventually, having eaten everything in sight, the pigs and goats died off as well, leaving behind a wreck of an island and a bunch of rabbits, which need much less food to survive.
Having nothing left to lose, biologists did a radical experiment to kill all of the hanging-on rabbits in 1979. In a hopeful note, this removal of the last herbivores led to rapid reforestation. Even on an isolated island, there can be a whisper of hope. Note that this isn’t *restoration*, it’s recovery. We don’t know what endemic species are permanently gone. We don’t know what they were and we’ll never find out now.
Similar studies about radically protecting fisheries from ALL human predation have led to similarly rapid recoveries. It’s not perfect, it’s not a great solution, but it shows us that this can be done. There is hope. It just takes that most endangered of all traits, political will.
While contemplating all this, I was at the Google campus early one morning and heard an astonishing sound—there were frogs hanging out in the brook that runs through the middle of campus, chug-a-rumping in the dawntime peace. It was a sound I’d never heard before at this spot, even after several years of early mornings. This stream, Permanente Creek, has been enjoying improved water quality over the past few years as the result of local legislation and a bit of enforcement. And you can hear the difference. The elegant herons and egrets are once again fishing in its waters, walking slowly up and down the bank on long yellow legs, looking for fish... and frogs… to eat. Their silent sight, and the frogs’ noisy presence, is a good sound. The quiet sound of recovery. At least here.
Permanente Creek with egret, near the Google campus. Pic from Wikimedia.