Putting the life back in science fiction


One of Them Difficult Problems

I don’t know why Agent Orange’s First Official Joint Session made me think about parasites, but there you have it.  This is actually something I’ve been dealing with for awhile now, and since the problem is only going to get worse unless (and until) we innovate our way out of this particular pickle.

The problem is fairly simple: if you want a sustainable society, you need to recycle almost everything.  The problem with recycling stuff, especially organic materials, is that it makes controlling pests, pathogens, and parasites very, very hard, because they move very well in streams of unprocessed materials.  After all, a large majority of species on Earth are parasites (per Zimmer’s Parasite Rex), and we, erm, they, evolved over the last billion-odd years in a world where the elements of organic matter are recycled extremely well, give or take some oil and coal fields.  So it shouldn’t surprise anyone that our attempts at recycling and repurposing are spreading parasites and pathogens all over the place. 

The issue I’m dealing with now are the Polyphagous Shothole Borer and Kuroshio Shothole Borer, two non-native tiny beetles that are morphologically identical (DNA distinguishes them).  They’re from southeast Asia, arrived in southern California probably on infested pallet wood a few years ago, and now they’re on the march.  They’re sort of a perfect storm: there’s no sure cure (yet), they attack something like 100-odd different species of trees, from sycamores to avocados (meaning that both the Department of Forestry and the Department of Agriculture say the other one should deal with it), and they spread really, really rapidly.  UC Irvine has spent tens if not hundreds of thousands of dollars chopping down and grinding up all the big sycamores on their campus, as the beetles are killing every single one.  The beetles are so small that, to kill them by grinding up wood, you’ve got to chip up infested wood in to pieces smaller than an inch across.  Bigger than that–mulch say, or firewood–and the beetles can fly away and infest a living tree.  Since the damned beetles inbreed (the males mate with their sisters inside the tree, rather than flying off to find unrelated females, and hence pheromone traps won’t work), even one pregnant female can start up a new infestation.

Scary, right?  Well, Cal Recycle has a new law that California is supposed to stop throwing  greenwaste (beetle-killed trees, for example) in landfills.  Instead, greenwaste supposed to be mulched, ideally composted but not necessarily, and spread somewhere so that the carbon can become sequestered in the soil.  Their target is things like ranch lands, landscaping mulch, and so forth.  Since many California counties don’t have the huge mulching and composting facilities needed to handle all the greenwaste California produces, a lot of it is going to have to be trucked a long way to the few big facilities, then many more miles to where it gets used.

In theory, not throwing away greenwaste is a good thing.  In a landfill it might decay anaerobically and emit methane, which is a worse greenhouse gas than CO2.  All good so far.  Unfortunately, moving massive amounts of greenwaste around and out of southern California is almost certainly going to move the Polyphagous Shot Hole Borer all over the place.  So will the guys who collect dead wood for firewood and drive away with it (many farmers get rid of dead fruit trees by leaving it as free firewood by the side of the road.  It saves thousands of dollars on chipping and grinding it).  And don’t worry if you miss out.  Climate modeling shows that these beetles will do just fine in Arizona, Florida, and Hawai’i.  And the world is getting warmer, which has the beetles stroking their little mandibles with glee.  North America will be theirs, unless the researchers can get about five million dollars to test and release the parasitoids they’ve found that will control the beetles…

Of course it gets worse.  We’ve got, what, 100 species of Phytophthora running around in plant nurseries in California right now.  Phytophthora infestans is Irish potato blight, P. ramorum is sudden oak death, and P. cinnamomi is devastating trees throughout Australia.  And we’ve got them all in California, along with many others.  Every nursery tested so far has at least one Phytophthora present, and we move nursery plants all over the world, exporting and important.  The group I work with, California Native Plant Society, is starting to work with native plant nurseries to implement sanitation procedures to control the spread of these buggers, but it’s slow going, and doesn’t even touch the big commercial nurseries, which are probably infested as well.  We’re such a melting pot for Phytophthoras that we don’t even know how many non-native species are present here.  Some of them are new to science.

And if you want to take it personally, of course we can deal with the spread of antibiotic resistant bacteria, or pesticide resistant pests, or drug resistant parasites, and so on.

These all get back to the basic problem: Yes, we can control the spread of any of these things, if we’re willing to pay the bill and restructure our lives around not spreading it.  The problem is, it takes resources and energy to do so.  Whether it’s something that infects plants or people, the simplest way to halt infections is to clean, sterilize, throw out infected material or incinerate it, and so on.  If you want to stop the production of greenhouse gases, you can’t burn it, it might emit methane from a dump.  Your best choice is to compost it, but that won’t necessarily sterilize it, or reuse and recycle it (you want to recycle and reuse medical waste?  Good luck with it).  To put it more generally, stopping infection is about stopping transmission.  Living sustainably requires (ideally) facilitating the transmission of everything into a new use.   Unfortunately, we live in a time when we’re going to need to do both increased sanitation (public health is more reliable than miracle drugs), and increased recycling.  Simultaneously doing both of these safely or efficiently is a difficult problem.

Fortunately, with the case of greenwaste, it only took about a year of yelling for Cal Recycle to acknowledge that there was a real problem with their greenwaste plan.  That’s pretty fast for a bureaucracy.  I’ll give them credit for that.  Getting the hospital workers to be better about sanitation seems to be a bit harder.  But that’s another story…

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8 Comments so far
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Combine incineration and power production. That would at least be a start.

Comment by Mike Darke

Five comments on this, to start with:
1. You’re probably the millionth person to think of this.
2. The existing biomass-to-energy plants are going out of business, because both natural gas and now wind and solar are cheaper.
3. They are still trying to get new business, but the owners of such plants blame regulation for forcing them out of business (I heard this at the same conference that had Cal Recycle listening to the shot hole borer researchers).
4. The problem with biomass to energy is that it works best when you’ve got a constant stream of biomass coming in, and it’s all the same kind of stuff. If it’s a heterogeneous stream, and worse, if it comes in irregularly, it’s inefficient.
5. Another problem with burning biomass is that about half the carbon goes back into plants, about half the carbon stays in the atmosphere, and half goes into the oceans. Congratulations, you’ve added to climate change. If you burn a 50 year-old tree, it will take a similar tree about 50 years to take that carbon back out. If we were calling this money, it would be a bad bet (I’ll pay you back in 50 years for the loan now), but for some reason, the state of California calls this carbon neutral. Stupid accounting tricks get in the way of solutions.

Now, if we could get the biochar crew off their collective butts and scaling up their projects to handle the influx of infested wood, we might start getting somewhere…

Comment by Heteromeles

A new report from the UK indicates that burning wood for power in the UK using US sourced wood from tree farms has a worse carbon footprint than using fossil gas. This is due to the carbon debt from logging before the forest recovers.

Comment by Alexander Tolley

Stupid question, maybe: What would happen if these beetles are left unchecked? Can they drive these 100 or so susceptible trees to (local) extinction?
From your post, my impression is that an unchecked infestation will kill an avocado plantation or other forest of only susceptible trees, is this correct?
Are they a serious danger to a mixed ‘natural’ forest? Do they have predators in Cal.?

I’m not disputing that this is a difficult problem, I want to understand the magnitude of it.

Comment by martin089

Sorry, I’m still digging into this. So far it looks like willows, box elders, sycamores, and castor beans have high mortality rates, cottonwood, sycamores, and alders have intermediate mortality (but a lot of them have died). Oaks and a lot of others don’t. and I’m not sure what’s going on with avocados. The way I understand it, there are trees they really like, but when all those trees are fully infested, the beetles will attack anything nearby, whether or not it kills them.

Comment by Heteromeles

Oh, and let me throw a technolgical fix (inspired by your comment re biochar) in here: Mobile Mulchers exist. Producing char in large covered kilns is maybe an (almost) lost art by now, but can be done. So mulch (or otherwise cut to pieces) in place, and then use one two charification processes:

1) errect kiln, using modern construction equipment (excavator, or farm tractor with front loader) this is probably a day of work at most. Pad with earth, then cover with tarp (tarp for gas tightness, earth to protect tarp from heat). Add chimney (with exhaust treatment, secondary burner for tars and CO). Composting plants have these lances with temp. sensors mounted on them to take temp. profiles of large heat, build some of those to withstand the charification heat.
Use forced external areation to control the process (just blow air unter tarp at several places). With enough temp. sensors you can track the approximate temp. for each volume element in your kiln. Charification can be approximated as a function of time and temp., simply track that each volume element has spent enough time above a certain treshold temp. If certain batches don’t get hot enough, punch a lance through the wall and add air there.
You would need to construct the chimney with exhaust treatment (an off the shelf mobile flare will likely have problems with tar condensation), the temp. sensor lances and a small PLC to control the fans.

2) Prefab a hoffman kiln (https://en.wikipedia.org/wiki/Hoffmann_kiln) from stackable skips or other containers, to be assembled on site. Didn’t put much thought into this one, but could also be doable.

If live where a Cory Doctorow story, the above would be trivial (or could be developed in a paragraph break), as things are, I still think this is doable.

One could also shop around if there are wood treatment processes that would kill the beetles (anything with high enough temp.) and exist as mobile equipment, I know nothing of logging and wood treatment so not sure there is something.

Comment by martin089

oops, totes forgot that hoffmans kilns where about solving the energy recuperation problem in brick burning in times before conveyor belts and forced areation. scratch that for now. A similar setup could be useful to achieve a semi-continuos counter flow operation withour much specialized solids handling equipment, needs a bit more thinking.

One could likely build mobile kilns by lining dumpster contaienrs with refractory bricks and installing blowers, areation grill etc,

Comment by martin089

Good point. There is a mobile system called a Burn Box that generates energy from burning wood on site. I saw a presentation on it, and a CALFIRE guy said they’d tried it (presumably in the Sierras) and found it to be labor intensive. I suspect things like this are the hidden issues with technical fixes. It’s not a bad conceptual solution, but if it takes a bunch of people to keep it working, that gets expensive.

My understanding (from the UC Irvine guys at the same conference) said they were spending >$1000 to shred their large campus trees to stop the spread of the borers. So far they’ve taken down over 1,000 trees, so it’s getting expensive.

Comment by Heteromeles




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