Data I’ll never publish II: Salinity and herbivory

I spent a lot of my second year of grad school thinking about salinity and insect herbivory. Generally, insects don’t like very much salt (i.e. how many marine insects have you seen?). Salt is a fairly effective herbivore deterrent – an observation seemingly first made in 1980 by D. Newbery in an Oecologia paper on mangrove herbivory. I made the same observation, and tested it experimentally, in chenopods in a 2014 paper (also in Oecologia – they’ve seemingly cornered the salinity/insect herbivory market).

Coconut palms might be the most widespread and useful (to human) halophytic plant. They were useful for that hammock, at least.  Abaco Island, Bahamas, 2011.

Plants are also affected by salt and have myriad ways to deal with it, basically all variations on either excluding it, sequestering it, or excreting it. Obviously some plants are much better at dealing with salt than others (see mangroves, Zostera, etc.) – we call plants that are adapted to saline environments “halophytes” (i.e. salt plant in Greek). I happened upon a little, weedy, nonnative, and pretty much unremarkable chenopod – Oxybasis glauca – growing at the edge of a building in Davis and somehow I decided it was a pretty cool plant. Given all the other cool halophytes available, I’m not sure why I chose this plant to do a bunch of experiments on, but I did.

This is Oxybasis glauca growing in volcanic sand on the edge of Mono Lake, Mono, CA. I was with a group of about 30 people when I found this and was very excited. I couldn’t really even articulate a single cool thing about the plant – it is salt tolerant, but every plant in that area is salt tolerant. Maybe the coolest thing is that Oxybasis species have really small seeds compared to Chenopodium or Atriplex… maybe there is nothing special about it?

Like most Atriplex and Chenopodium (the genus which Oxybasis was split from) species, Oxybasis glauca has salt bladders – little bubble like trichomes which the plant shunts salt to and then they burst, an odd but effective form of salt excretion. This leaves a layer of salt on the outside of the plant. This protects the plant from herbivory somewhat.

 

Pre- (above) and post- (below) bladder burst O. glauca leaves (lab-grown).

 

Because O. glauca is salinity-tolerant and the primary herbivore of most weedy chenopods in the valley, the spotted cucumber beetle (Diabrotica undecimpunctata), doesn’t like salt (see my 2014 paper), I wondered if there might be a refuge from herbivory effect at higher salinities and maybe there would be an intermediate salinity where the plant would still grow well, but herbivores would be deterred. So I did an experiment – I grew plants in three salinities* and then exposed half of them to a week* of cucumber beetle herbivory. I expected herbivore pressure would be most intense at low salinities, but also growth would be retarded at higher salinities.
So the hypothesis looks something like this – if plant “performance” is on the y-axis and the green line is effect of herbivory and grey the effect with solely salinity, if there is some overlap, the plant might do best at that overlap point (or it might not). (note: this is not a particularly good graphical representation for a number of reasons).
What did I find?
Plant response to salinity (w/o herbivores):
Salinity increasing left-right. Standard deviation plotted.
Plants did worse as salinity increased (as expected).
Herbivory:
Salinities increasing in treatments 1-4. Standard deviation plotted.
Total leaves damaged by the herbivores decreased with increasing salinity (as expected, as they are less palatable), but because the plants had fewer leaves, the proportion damaged increased.
THE INTERACTION
Biomass of plants. Dark green: with herbivores, light green: without herbivores. Salinity increasing left to right. Standard deviation plotted.
Sadly, there wasn’t. Beetles didn’t really have an effect on biomass (or any other metric). Maybe I didn’t have them in there for long enough? Maybe they really don’t have a fitness effect (I can certainly believe this).
Maybe this data will be useful to someone. Email me for the sheets.
*Note: the exact procedures are in one of about 40 notebooks in my office, so I don’t actually know exactly the salinities or number of days right now. If anyone is interested for any reason, I can easily dig this up.

Can we use Christmas trees for fire management?

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A Sierra Nevada forest in wintertime.

Over the past week, I’ve been talking trees with my friends and colleagues. But not any trees: Christmas trees. The question on the table: what is the environmental impact of a Christmas tree, real or artificial?

The whole thing began when a friend, a big plant lover, urged others via Facebook not to buy a real tree in order to respect the environment. Many comments followed. A mutual friend, knowing that I’d done some reading on this topic before, asked me to share some of the sources I’d found on the topic.

A lot of environmentalists assume that an artificial tree is the right choice: it’s reusable, and it doesn’t require cutting down a living tree every year only to stick it in your house for a couple of weeks until it dies. But the evidence says that this isn’t necessarily true–indeed, multiple sources, including a thorough “Life Cycle Assessment” by an environmental consulting firm, say that natural trees are actually the better choice: most Christmas trees are grown on farms, where young trees are planted annually to replace the ones that are cut down, while artificial trees are made of environmentally harmful PVC and are usually transported from China.

Others argue that the artificial vs. natural debate doesn’t matter much at all–no matter which tree you pick, the carbon footprint is far less than an average person’s footprint for a single day. And if you do want to minimize impact, details like where your tree comes from, tree farm practices, how many years you reuse your artificial tree, etc. are probably the more important choices. There are creative, earth-friendly options on both sides: a live tree that can be planted in your yard, for example, or a fake tree made from unconventional recycled materials. (The “greenest” tree I ever had growing up was definitely when we cut off the top ten feet of a Norway spruce that had toppled over in our backyard during a storm.)

And so I compiled all of this into an e-mail, finishing it off with something like “I support natural trees, assuming you’re not randomly going into the forest and randomly chopping down a tree, which few people do anyway.”

And then it occurred to me that I was perhaps missing the forest for the trees. I live in California. I care about wildfires and fire management. And one of the main strategies for managing forests for wildfire in California? Thinning small trees to reduce fuel load.

Thinning forests is controversial (really a topic for another post)–and it’s not as cost-effective or ecologically beneficial as getting real fire on the ground. But there’s no smoke, it’s precise, and has support from many interests. In any case, it’s one of the strategies we have, and one that we’ll need to continue to use as part of our forest management toolbox.

So here’s the holiday question of the day: in California, is the environmentally-friendly, fire-friendly choice to cut your Christmas tree from a forest rather than a farm?

The small trees that serve as ladder fuels (fuels that carry a fire from the forest floor to the treetops) would be pretty good Christmas trees. Many such trees are small enough to fit in your house, and they are shade-tolerant species that have the Christmas tree look, like red and white fir.

I’m not the first one to have the idea of using Christmas trees for fire management, but it’s not an idea that shows up often in real vs. artificial debates, which tend to focus on the tree’s carbon footprint. Here is one really good article on this idea, from UC Cooperative Extension Forestry, which provides lots of useful information on cutting your own tree in California.

But is cutting a Christmas tree for forest management really a good or practical idea?Individuals cutting single trees on a small scale probably won’t have much effect on fire behavior. On a larger scale, there may be more cost-effective uses for the products of thinning than Christmas trees. And as is the case with artificial and farmed trees, there are so many factors involved in choosing a tree that it would be hard to argue that cutting a tree is a better choice than anything else, even in California.

So what’s the takeaway? Here are a few:

  • Always consider the forest AND the trees–individual trees can only thrive in a healthy ecosystem.
  • Think about your local environmental context when you choose a tree, or when purchasing other environmental resources. Choosing a tree in California may be different than doing so in New York.
  • When deciding what is “environmentally-friendly”, think beyond carbon footprint (carbon is definitely important, but there are other considerations, like wildlife habitat and wildfire).

Any thoughts from the audience? If you live near forests where thinning takes place, have you considered getting your Christmas tree this way?

Happy holidays from Talk About Fire!

P.S. Speaking of fire, if you have a live tree, make sure to keep it watered, turn the lights off when you’re not around, and avoid real candles and other fire hazards. We don’t want to move the fire from the forest to your home! Other tips here.

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You can always create a lovely mixed-candyfir forest to celebrate!

Letting Fires Burn: Paper Policy and Public Opinion (Part 2)

Last week, I discussed institutional barriers and incentive structures that make it difficult to get fire on the ground in the form of managed wildfire or prescribed burning. I argued that these disincentives can work in a feedback loop with public opinions to keep the suppression-dominated status quo in place. Now it’s time to discuss public opinions: in a 2015 paper in Nature, North and colleagues argued that public support for fire management reform could help propel change. The argument is that public opinion will drive policy, and the implication is that good science and education can help shape public opinion.

Where do public opinions about fire come from, anyway? There’s a sense in much writing about fire that the natural state of things is for people to fear fire, and the idea of fire can be a positive natural process or a tool for ecosystem management is some kind of novelty.

But for the United States, this isn’t really true. Indigenous groups here and abroad have had long histories of using fire as a tool to shape the landscape, and many settlers picked up these techniques and supported what was then called ‘light burning’ in the late 19th and early 20th centuries. Fire wasn’t eliminated from many North American forests based on ‘public opinion’–it was eliminated by policies that made indigenous burning and ‘light burning’ illegal, and by the implementation of widespread fire suppression by the early Forest Service, a then-new organization looking for purpose (see Timothy Egan’s The Big Burn or the PBS documentary of the same name for a good history). The ‘public opinion’ that ‘fire is bad’ came top-down.

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Gifford Pinchot and the early Forest Service found their purpose in fire suppression. (Photo credit: USDA)

So the ‘fire is bad’ narrative wasn’t originally the default position. But when the fire community talks about changing public opinion today, it’s usually based on an assumption that people today think fire is bad and scary, and policy will change if only people learn that fire can be natural and good. The strategy is to continue to persuade people that prescribed burning and managed fire are good and total fire suppression is a mistake.

In order to make their case, fire researchers and educators like to point to scientific evidence that demonstrates the benefits of fire. For example, a recent article reported new results in wildfire research: a study in Yosemite found that forests that had had neither fire suppression nor prescribed fire over the past 40 years–just managed wildfire–were more resilient to fire. This was interesting, but not really a surprise. Researchers in the fire science community have been researching the effects of different fire regimes and fuel treatments for decades. What did surprise me was a quote from one of our author heroes of fire management reform, Scott Stephens, who said, “I think [the paper] has the potential to change the conversation about wildfire management.”

Does a single paper really have the potential to change the conversation? We’ve been making the same arguments since the 60s, yet so little has changed in terms of fire policy.

Talking about the benefits of fire might be a good strategy to get public support for forest fire reform. But does public support for reform in general matter, or does this just result in the same old paper policies of the kind that have been on the books for decades?

I’m starting to think that this isn’t the right strategy to make change happen, for two reasons. First of all, I’m no longer convinced that the general public desperately needs a lesson on the benefits of wildfire. Second, I’m skeptical that more evidence or education focused on the benefits of fire will lead to any kind of radical policy change.

In my (ongoing) research, I have asked hikers to describe their perceptions of wildfire in the United States. By far, the most frequent words that they use are “natural” and “necessary.” Many people think that public attitudes are a primary barrier to implementing prescribed fire; recent research suggests that this isn’t really true.

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Prescribed fire in Oregon. (Photo credit: BLM)

This lines up with what I have observed in casual conversations and on social media. Nearly every article on wildfire I read mentions the downsides of fire suppression and touts the benefits of planned or managed fire, whether or not it applies to the particular wildfires in question. There are even children’s picture books about fire ecology. 

I’m sure that there are still many people who associate wildland fire with destruction only. Most people don’t read the New York Times, attend ranger talks at National Parks, or have the advantage of attending a fire ecology field trip. My hikers might be a skewed sample–many live in a university town, and all have made the choice to spend a day out on the trail. But for many audiences–including policymakers and many residents of fire-prone landscapes–the message has stuck.

Here are some things that a large portion of the public will agree with:

  1. The United States has a wildfire problem that needs addressing.
  2. Wildfire can be a natural part of ecosystems, and fire suppression has contributed to (1), at least in some areas.
  3. Prescribed burning is a good tool for hazard reduction and ecosystem management.

Here are some things that most of the public (at least in the United States) will not agree with or acknowledge:

  1. Our default should be to stop suppressing wildfires, especially in beautiful natural areas such as National Parks.
  2. Smoke is to be expected in fire-prone areas, and I am willing to have smoky skies if it means mitigation of catastrophic fires in the future.
  3. It is primarily my responsibility to protect myself and my home during a fire.

Too much of changing public opinion is focused on things that the public already agrees with. We should keep doing research and keep talking to people about the costs and benefits of putting more fire on the ground, but this is not enough to drive major policy changes. If it were, we’d see more fire on the ground today, given the many papers and knowledgeable citizens already out there. Instead, I see endless Twitter posts from CalFIRE reporting that another 50 acre fire is already 90% contained (these fires are far, far more common than fires like the Soberanes Fire, which burned for months before reaching this level of containment). We’d hear more about fire managers than the hundreds of firefighters ‘battling’ fires.

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Typical report from CalFire: every fire is a battle.

Environmental historian Stephen J. Pyne has argued that the fire-friendly policies of the 60s and 70s became rare in practice due to a combination of the national politics of the 1980s and the 1988 Yellowstone Fires. Pro-fire rhetoric couldn’t stand up to the scale of the destruction of beloved vistas in Yellowstone. In addition, as time has passed, populations have grown in fire-prone regions, concerns about air quality have grown, and climate change has thrown a wrench into everything, simultaneously increasing urgency and uncertainty in fire management.

We accept the idea that something needs to change in fire management. We accept the idea of more fire on the ground, at least in theory. But when it comes time to put these ideas into action, in the places where we live and work and play, Americans don’t really want fire on the ground. It sounds great if it’s happening somewhere else. But if there’s a real chance that people and homes and places we love could be at risk, we still want firefighters to come put fires out as soon as possible. We believe in prescribed fire where it’s appropriate, but not when the smoke is going to keep us inside or block our views. Personal and political reasoning often trump science, and short term interests usually outweigh long term goals.

There’s a comparison to be made here to efforts to reach the public on climate change and evolution. Now, there aren’t really any ‘wildfire deniers’ that I know of, but in other respects they are similar situations. Many researchers in these fields assume that more research and more explaining the facts will lead to change, but there is evidence that this simply doesn’t translate into action. In all three cases–climate change, evolution, and wildfire–most people know the scientific argument perfectly well. Even climate or evolution skeptics can tell you what the scientists believe. But individual action or broad based policy change are shaped by more than science. 

What can we do to effect real change in wildfire policy? There’s no simple answer here, but I doubt that a single journal article will be a turning point. Neither will another news article about “fighting fire with fire.” If years of doing the same old thing has resulted in little change, we need to rethink our strategy. Instead of telling people that not all fires are scary, we should actually help people learn to live with fire on the ground, even when it scares us.

Why We Don’t Let Fires Burn: Paper Policy and Public Opinion (Part 1)

This week, environmental writer Andy Revkin published an article in the New York Times titled “Will California Ever Let Sierra Nevada Forests Burn?” This title showcases the main problem of fire management for the past 50 years: we’ve long known that what we’re doing isn’t working (fire suppression), we’ve long known what we need to do to mitigate that problem (get more fire on the ground), but we don’t do it, at least on the scale that would be needed for effective forest management.

Why not?

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A Sierra Nevada forest burned during the Rim Fire.

There are two kinds of barriers: institutional and policy barriers (rules or customs that shape how agencies make management decisions) and public barriers (public opinion). These are not separate–policies are designed based on what agencies think people want, and public opinions are shaped by policy and policymakers. This interaction of institutional and public barriers can create a feedback loop where nothing ever changes.

Let’s look at the institutional and policy barriers first. I’ve separated my discussion of public barriers into a second post, since this one was getting too long.

The federal agencies that manage wildfires have had policies that include management alternatives to fire suppression for decades. The National Park Service and the Forest Service have had policies that allow for managed wildfire and prescribed burning on the books since 1968 and 1978, respectively. But both are relatively rare even today.

Researchers Scott Stephens and Malcolm North have been heading up a charge for real change in forest fire management, creating an ever more forceful argument that puts managed wildfire at the forefront. Last year, they wrote an article for Science with colleagues titled, concisely, “Reform forest fire management.” They highlight the environmental and monetary costs of fire suppression and argue that institutional obstacles are the major problem. They suggest that public support of reform will help, but the public is not presented as the major obstacle to change.

More recently, in a November 2016 article in Ecosphere, Stephens and colleagues kick the argument up a notch, suggesting specific policy changes that could upend those institutional barriers. Most radically, they suggest changing the “default rule.” Currently, managed wildfire needs justification, while suppression is the default rule. The paper proposes a flip: managed wildfire becomes the default, while continued suppression would require a disclosure of environmental costs.

Changing default rules is a great way to change behavior, because people tend to stick with the default option (see economists Richard Thaler and Cass Sustein’s thought-provoking book Nudge for more on this). Changing a default rule forces a change in the status quo, unlike sitting around waiting for people to choose differently. Choice is preserved, but default rules ‘nudge’ people and institutions toward particular choices that they might otherwise not choose. A common example is making organ donor status the default when people get a driver’s license, forcing them to opt-out rather than opt-in.

In the context of fire management, though, changing the default is a pretty big change in the status quo. If this change were to be implemented, it could be very effective. The problem is changing the default rule, which seems pretty unlikely at this point in time.

A related policy discussion that has come up is the role of the Clean Air Act as a barrier to prescribed fires. Because prescribed fires are intentional, human-caused events, smoke emissions are subject to pollution caps. Unplanned wildfires, which are often human-caused anyway and tend to create much greater amounts of smoke, are not subject to Clean Air Act regulations–so long as the agency is trying to suppress the fire (see a discussion by law professor Eric Biber here). While the Clean Air Act doesn’t disallow prescribed burning or condone wildfires, the result is a pretty big ‘nud

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Wildfire smoke from the 2016 Sand Fire. Smoke from unplanned wildfires is not subject to Clean Air Act regulations so long as they are suppressed.

ge’ to keep the status quo of suppressing fires quickly and doing prescribed burns only on rare occasions.

And then there’s the monetary disincentive. Alternative strategies cost money, and most of the available money is going to suppression. As Sara Jensen and Guy McPherson articulate in Living With Fire: Fire Ecology and Policy for the Twenty-First Century, most recent attempts at forming or amending federal fire policies have a contradiction at heart: a recognition of what should be done (more research, forest management, and fire on the ground) but resource allocations that support the status quo (most money going to fire suppression, leaving little for anything else).

In recent years, fire suppression costs have grown ever larger. These funds come from annual budget for agencies, namely the US Forest Service.  Each year, the Forest Service has an increasing portion of its budget going to suppression (now more than 50%), further reducing funds available for management alternatives and research. Other kinds of natural disasters are funded differently, and one strategy for providing more funds for projects like prescribed burns has been to change the way suppression is funded. The Wildfire Disaster Funding Bill is a proposed measure that would have allow fire suppression for catastrophic fires to be funded like other disasters, freeing up agency funds for other uses, like research and prescribed burns. Unfortunately, the bill stalled in Congress this week, when Speaker of the House Paul Ryan announced that the talks that included this bill were unlikely to resume until next year. The bill has had bipartisan support, and it sounds like it’s still on the table, but the Missoulian described the news as “budget fix for fighting wildfires dies in Congress.”

So institutional incentives and policy design work together with monetary allocations that reinforce the status quo. Any fix will require a powerful change that rewires the incentive structure and funding availability to favor fire on the ground over total suppression.

Why are the incentive systems set up this way? Why are the defaults still set against prescribed fire and managed wildfire use even though research has long shown support for these strategies?

This is where institutional barriers meet public barriers. Stay tuned for Part 2.