Summer moves to fall, and fire season is accelerating. Once again, it looks to be a major season, (perhaps fueled by a weak monsoon) although we have not yet had a really big one in the Sierra Nevada. Jane Little recently put out an article in High Country News regarding the dead trees in the Sierra Nevada and the potential for fire. So, like the Roman god Janus: looking backward, looking forward,... what would Janus do?
The Roman God Janus has two faces. One looks backward to the beginning of thing; the other looking forward to the future. Janus, for example, was the god of the beginning and end of war. Returning to my recent post, on conflict among environmentalist, I am thinking of how Janus can provide insights on how to end the conflict over fire management strategies for the Sierra Nevada.
This, by the way, is not a new debate. We can loom to the 1996 Sierra Nevada Ecosystem Project, the 1998 Quincy library group, the 2002 Healthy forest initiative and 2003 Healthy Forest Restoration Act to see this debate cycling round and round.
Previously I have written on environmental conflicts, particularly across different environmental values. However, we have a deep interst in climate change, drought, fire and resource management. Zack Steel kicked off this blog in fall 2015 with a post on fire management. We have subsequently written on the current California drought and its impact on Sierra forests. This time, I would like to get into a bit more detail about the academic conflict on the role of high severity fire in the Sierra Nevada, how this links to social conflict over forest management, and how we might move forward.
To do frame this conversation, we turn to Janus. Janus looks backward, as ecologists often do. As ecologists we look backward to try and understand what historical data tell us about 'natural' conditions under the assumption that we should strive to replicate natural conditions through whatever management we choose to exert over ecosystems.
An old adage says that "hindsight is 20-20." Using historical data to reconstruct past fire regimes, however, is anything but 20-20, and hence arises an on-going academic debate about the historic role of fire in the Sierra Nevada.
The two sides of the issue are straightforward. Using historical photos, early settler descriptions and missionary accounts, and non-fire suppressed analog environments, most forest ecologists describe the pre-20th century Sierran forests as generally open and park-like, with small clusters of trees and a lot of open space. Major champions of this view as a mdel for forest management are leaders in forest and fire research in the region: Malcolm North, Scott Stephens, Brandon Collins, Hugh Safford and many others. Together they represent over 100 research publications on this issue.
In sharp contrast to this view, another set of authors most notably Chad Hanson, Dennis Odion and William Baker, have championed the notion that high severity wildfire was a prevalent component of the historic landscape. These authors use some of the same sources of data and land survey records.
However, my intent is not to debate the issue of the role of high severity wildfire in historic forests of the Sierra Nevada. Instead, I am writing this to make the simple point that Janus would have us not dwell on the past, but to both look backward, using historical models, and forward to ask how we would like forests of the Sierra Nevada to look and function.
Forward-looking leads me to a simple conclusion: whether or not there was extensive historical high severity wildfire does not change these simple facts:
A. People don't like high intensity fires.
1. Large, high intensity fires put lives at risk. These are the kinds of fires where firefighters die.
2. Large, high intensity fires put property at risk. These are the kinds f fires that destroy homes.
3. Large, high severity fires generate a lot of smoke. Smoke causes health problems.
4. Large, high intensity fires create erosion risks, which are safety and environmental hazards.
B. Lower density forests are likely to create environmental goods that people like.
1. Lower drought stress in trees, and likely lower mortality rates during drought (although studies on this are on-going).
2. More water infiltration and hence ecosystem throughput of water to downstream water uses (work on this continues as well)
3. Reducing stand density means cutting trees. Cutting trees means jobs and income.
C. Changing climates increase the risk of biological loss with large-scale high severity fire.
1. Large, high intensity fires accelerate ecosystem transition, placing slow responders at risk
2. Large high intensity fires inadvertently degrade habitat for old growth dependent species such as spotted owls.
Getting to a place that reduces the risk of these fires, however requires lots more timber removal. Timber removal has some downsides, such as:
A. People don't like logging
1. Logging causes erosion and the environmental risks associated with that.
2. Logging requires roads, roads are habitat fragmentation.
3. Logging causes direct damage to habitat used by species.
B. Lower density forests are likely to create some environmental risks that people don't like.
1. More open forests are more prone to invasive plants such as broom.
2. More open forests support fewer at risk, old-growth dependent species (Pacific fisher, California spotted owl)
C. Lower density stands may still experience high intensity fire.
1. No one is arguing that there wasn't any high intensity, high severity fire in the past, nor that forests were, on average more open. The argument is how much. Hence, even more open forests are likely to experience
We know that climates have changed since the 19th century. We know that ignition sources and fuels have changed since the 19th century. We know that the forests of the Sierra Nevada are going to change in the future and that this will increase risk to some species that currently reside there. The way forward with managing fire in the Sierra Nevada is to carefully weight the benefits and costs of different management into the future, decide what we want, and then look to the past to best map out how we would get there.
In contrast, the current debate smacks of choosing arbitrary historical benchmarks to glean where we should go into the future. That approach places too much emphasis on the past. We need to look forward to vision the Sierra Nevada we want and that conditions will support and then look backward for evidence of processes that will get us there. And that, I think, is what Janus would do.
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