California has been facing severe drought conditions since 2011. Much of the media coverage surrounding the drought has been given over to direct human concerns, such as the folks painting their lawns green (rather than, say, landscaping with native or drought-resistant plants) and water restrictions for residents and farmers. However, lurking in the background, there’s another sign that this drought is by far the most severe in modern history. California is facing a rising number of dead trees, over 100 million at last count.
Drought doesn’t always kill trees directly. Rather, it weakens them to the point where other stresses, normally endurable, become fatal. Bark beetles, fungus, and disease kill drought-weakened trees more easily. Extremely long-lived trees, such as the giant sequoias for which California is famous, are even succumbing as the water stress kills them from the top down. There’s just not enough water for the sequoias to maintain a constant pull from the roots to their tops, hundreds of feet in the air. When the water pressure breaks, it creates a gas bubble, like an embolism, cutting off the tree’s water flow in that spot. Less water means more pressure, more breakage, and eventually, dead trees.
Giants in the Face of Drought, courtesy of bioGraphic
The United States forest service currently budgets $43 million to maintain roads and trails in California forests, but a lot of that money is spent instead on fighting forest fires. While the corpses of dry, dead trees are a fire hazard, the irony is that smaller, controlled fires would help the situation in some cases. Fires clear out a lot of the underbrush that makes big fires worse when it’s allowed to pile up for so long. Taking out smaller trees would also save what water there is for the giant sequoias, which are almost immune to burning once they’ve lived for a few hundred years.
On the other hand, a certain number of fallen dead trees play a key role in the life cycle of a forest. By providing protection from erosion, wildlife habitat, shelter for seedlings, and recycling nutrients back into the soil, dead trees are just as important in their way as living trees are. Capitalizing on the drought by clear-cutting California’s forests in anticipation of falling dead trees, as lawmakers from both major parties are proposing, is not necessarily the best idea. It might be understandable to preemptively cut dying trees that are a danger to people or property, but since the drought is likely made worse by anthropogenic climate change, this is about as sad as having to put down a vicious dog that was trained poorly by its humans.
There is still some hope to salvage in this unfortunate situation, though. Ireland is likely to warm in the coming years and may be ideal future habitat for the descendants of California’s giant redwoods. With this in mind, the seventh Earl of Rosse, Brendan Parsons and the Irish environmental organization Crann are teaming up to plant 2,000 redwoods around the Earl’s castle. The trees were once common in Ireland but disappeared after the last ice age.
Back in California, residents ought to consider killing two birds with one stone by building some Hugelkultur mounds. Hugelkultur uses rotten, dead trees to create fertile and water-saving garden beds. It seems to me that if you have an excess of dead trees, a water deficit, and a desperate agricultural industry, this is a solution that would benefit many.
In better times, California’s giant sequoias, living for thousands of years, seem nearly immortal. Fire and pests, which kill lesser trees, hardly make a dent. When they finally die, it’s because sequoias become victims of their own massive size, falling over once their soil has been undermined, or their roots rot or die from lack of water. They are metaphors for our own massive, world-eating culture this way, as industrial culture’s very size and lack of connection to our roots and the dirt beneath our feet cause us to collapse under our own weight and topple. The main difference? We are doing this to ourselves, while the dead trees are merely bystanders.