The US Forest Service just reported that there are 66 million dead trees in the six counties that cover the southern Sierra Nevada. Restraint, Resilience, Reponse or Realignment. Has our choice been made for us?
Nate Stephenson and Connie Millar wrote back at the start of this drought that climate change may be the greastest challenge to wilderness in the western US. In this paper, and elsewhere, they define four classic strategies for management. These are: 1. Restraint - we leave some places alone; 2. Reslilience - we manage to enhance the capacity of ecosystems to absorb stress; 3. Resistance - creating structures within ecosystems to help them withstand environmental change; and 4. Realignment - taking actions that foster change to align with future conditions.
So, perhaps 4 years of drought have altered our view. 66 million dead trees in 6 hard hit counties now; an absolute average precipitation winter in 2015/16 despite strong el Nino conditions; bark beetle damage on the rise. The number of dead trees is going to continue to rise (hey, Sac Bee quotes me in this one!). Trees do no recover quickly from deep water stress, there will be more mortality next year, and probably the year after that. And this will be true even if those years are wet.
Hence, we are now entering a period of reduced options. We don't need to consider some of those four management options; we aren't deploying them in meaningful acreage. We have been doing "Restraint" in spades. Restraint has resulted in a recent run in very large fire years, and 2016 looks to be more of the same. With all those fuels out there, I don't see how it doesn't end up a big fire year. Big fires now mean large areas with high intensity fire, leaving large areas devoid ot trees and devoid of seed trees for forest recovery. This leads to realignment, realignment, realignment. Although not realignment by choice, but by default. We do not yet know, for example, how much of the high intensity areas of the Rim fire that the USFS will be able to replant or how important grass and shrub encroachment may be into formerly forested areas. Time will tell.
The important food for though here is that the USFS now spends > 50% of their budget fighting fires and preparing to fight fires (52% in FY 2015). The US Forest Service Budget is $6.5 billion in 2016, but was flat from 2009 ($5.6 billion) through 2015 ($5.5 billion). The consequence is a shrinking capacity to do anything but step up our efforts to exert management restraint, and then watch systems as they realign.
The whole point of Stephenson and Millar's (and others) writing on the four R's is that we probably want to do deploy each of the strategies somewhere. As time moves on and manager are able to do little else than try and combat more and more, larger and larger fires. This does not leave much room for building resilience or creating resistance.
However, much of the high elevation is designated wilderness or National Park; places where we historically, and legislatively, take a lighter hand in managing systems. Perhaps large scale restraint is appropriate? So, is the question merely academic? I don't think so. (well, duh. I wouldn't write this otherwise).
Three reasons. First, we can't learn about systems unless we experiment, monitor and try to learn. We do not yet know whether we can create more resilient systems. A group of researchers is just now conducting the observations to try and figure out whether thinned stands have been more resilient during the current drought. Second, we can't really afford to not deploy resistance. Part of why we spend so much money on fire is that we have a public-private land boundary that forces federal agencies into defending build property from fire around their perimeters. Actually determining whether we can create resistant landscapes is integral to keeping firefight costs from escalating even further. Thus far we are in a very vulnerable state with respect to that private property.
Third, the spine of the Sierra is the climate change refugia of the far western US. The elevation of the Sierras, getting higher toward the south, results in a high pontetial for isolated pockets of cold habitat. During the past couple years remote cameras have observed both wolverine and wolves. These are recovering species migrating back into the region. Far more species lack the movement capacity of wolves and wolverines, but may need to use these habitats as refugia (e.g., a variety of rare plants and insects for example). These will need us to create pockets, or even corridors, of resistance, providing time to disperse through suitable habitat to reach locations of favorable climate.
California is reaching tipping points in many aspects of its environments (water, fisheries, endangered species, ...). I never thought that I would see the day when I feared that the forests of the Sierra Nevada felt close to a tipping point of catastrophic loss. As we see high intensity fires create more grassland and shrubland, I am deeply concerned about how extensive this may become given our current capacty to manage a problem that has spiraled out of our control.
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