A northern spotted owl in Marin County. Credit: National Park Service.

Spotted owls are one of the most iconic threatened species in the West. But despite two decades of work to bring them back, their numbers are still declining. That may be due in part to a new threat – not from humans, but from other owls.

You might picture spotted owls in a mossy Pacific Northwest forest – but they actually live right here in the Bay Area.

In a forest near Muir Woods, Bill Merkle, a National Park Service ecologist, plays a recorded northern spotted owl call. He's standing where a pair of owls had a nest last year.

"I think they're just probably 50 or 60 feet up there…" says Merkle. After a moment, he hears a faint call. Merkle runs up a steep slope that's covered in brush and poison oak. In the branches above his, he sees two spotted owls.

Listen to the QUEST radio story Spotted Owls Face New Threat

"So this would definitely be a pair. They're hanging out together," says Merkle.

Northern spotted owls aren't very big. They're a brown owl with white spots that's found from Washington state down to the Bay Area. They've also had the starring role in a decades-long battle between loggers and wildlife groups over their habitat. In many logging towns in the early 1990s, this owl was public enemy number one.

Merkle says in all, about 80 pairs of spotted owls are found on national park land in Marin County – and for 15 years, the park service has monitored the health of that population.

But recently, Merkle says they've been hearing a new owl call in the forests – a barred owl call.

Arrival of the Barred Owl

"The call often described as ‘who cooks for you?" says David Press, another ecologist with National Park Service. He's joining Merkle near Muir Woods to look for the owl that makes that call – the barred owl.

"You see anything?" says Merkle. They peer into a hollow cavity high in a tree – a cavity that used to be a spotted owl nest.

"Just at the base of it you can see a little bit of that barred owl," says Merkle. It's a female barred owl, sitting on her eggs. Merkle looks concerned.

"It's a troubling picture for the spotted owls," he says.

Barred owls are an invasive species, originally from the Eastern US. They first arrived in spotted owl territory in Washington and have been moving south down the coast – which makes this owl the frontline of the invasion.

"The barred owl is a little larger. It's a little more aggressive. And so in other areas where you have barred owls set up, the spotted owls aren't there anymore," says Merkle.

Barred owls take over spotted owl territory and in some cases, even attack them. In places like western Washington, the spotted owl population has been cut in half since the barred owl showed up.

David Press says he's already seeing a change in Marin. "Since the barred owls moved into the area, we've had a harder and harder time detecting spotted owls where they have been historically."

"The barred owls are really sort of adding insult to injury," says Paul Henson of the US Fish and Wildlife Service, the agency overseeing spotted owl recovery.

"The injury for the spotted owl was 100 years of habitat loss, and the sort of insult, the more recent insult, is barred owls have now shown up and are really out-competing spotted owls."

New Study to Remove Barred Owls

The Fish and Wildlife Service hopes to deal with the issue in a new plan expected to be released in a few weeks. It includes a barred owl study that's… raising a few eyebrows.

"We identified the need to do a focused study where we could test the response of spotted owl populations to the removal of barred owls," says Robin Bown, a biologist with Fish and Wildlife.

Which means…

"Well, basically it means permanent removal. We're going to look at all potential opportunities but the most humane way to do it is to shoot them. A shotgun removal is extremely quick, it's almost instantaneous."

Bown says they plan to eliminate barred owls from a few study plots to see if the spotted owls there do better. They also want to see if it's even feasible to remove barred owls by shooting them.

And yes, Bown says this is an idea that's not easy to consider. "Oh it's a very difficult thing. Even for those of us involved in this, it's a very difficult concept to say I'm going to kill one species to try to save another species. But it's also something that in some cases we need to do."

Back in Muir Woods, Bill Merkle says a lot of people are waiting on the results of the study to see what's next.

Budget cuts are also an issue. Just as more barred owls are arriving, Merkle says the park service's owl monitoring program has been cut.

"Now the situation is getting a lot more challenging just when I think the threats are getting more apparent with the barred owls. We know climate change is going to change things out here. It is a difficult time to be cutting off our monitoring."

If approved, the barred owl removal program would begin next year.

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Almond shells at the West Biofuels biomass test plant in Woodland, California.

When you think of where energy comes from, you might picture a power plant or maybe wind mills. You probably wouldn't think of a pile of 12 tons of almond shells.

California is hungry for renewable energy. Solar and wind power have taken off thanks to the state's ambitious clean energy goals. But there's another way to generate electricity — by using organic material like agricultural and tree waste. It's known as biomass power.

Matt Summers is an engineer with West Biofuels at their test power plant near Sacramento. California, by the way, is the world leader in growing almonds.

"So we've got more almond shells than anybody else. And you know, we know some companies that handle almond shells and they're always looking for somewhere to take them," says Summers.

Listen to the QUEST radio story How Green Is Biomass Energy?

But where some see a waste product, Summers sees an energy source.

"So this is the heart of the West Biofuels process," he says, pointing to a tower of industrial equipment that turns almond shells into electricity. First, the waste, or biomass, is fed into a reactor.

"We call it reforming, so we're re-forming what's biomass, what's almond shells into smaller particles that are gases," says Summers, describing their gasification technology.

The gas that's produced is a lot like natural gas, so it goes to an advanced generator where it's burned to produce electricity.

But this is where biomass is different from other renewables. The generator produces air pollution, unlike, say, a solar farm. So Summers and his team use pollution control technology to meet California's air quality standards.

Still, despite the emissions from biomass plants, many say there are big benefits to using waste as an energy source.

"Waste is pretty green," says Jim Boyd, a member of the California Energy Commission. "There's enough material out there to make thousands of megawatts of electricity."

Matt Summers of West Biofuels stands next to their fuel source.

There are a lot of unused energy sources out there, Boyd says, like construction debris and orchard cuttings. Biomass energy also has one big advantage over other renewables – reliability. Wind and solar power are variable since the sun and wind aren't available all the time.

"And instead of just thinking about building more natural gas plants to fill the void, we could utilize biomass plants because they are seven by 24 once you get them up and running," says Boyd.

But while other renewables are booming, biomass is on the decline in California. After dozens of plants were built in the 1980s, today, only a handful of new plants are being proposed. In 2009, biomass provided about two percent of the state's electricity.

"There's a great infatuation with wind and solar and very rare references to biomass and some of us are trying to turn that around a little bit," Boyd says.

One problem is simply cost. Biomass facilities need tons and tons of material and trucking it in from around the state isn't very economical.

The other issue gets back to the concern of whether biomass energy is really as green as supporters say. There's the problem of greenhouse gas emissions from biomass plants. Another controversy is over one particular fuel source: trees.

All those years of Smokey Bear and fire suppression in California have created very dense forests – which are at high risk for fires. Both private and public land managers have been trying to reduce that fuel load.

"In a lot of cases you'd do thinning operation where you take out some of the trees, usually the smaller trees, the less valuable trees," says Bill Stewart, a forestry specialist at the University of California – Berkeley.

Stewart says most of the material removed from forests is either burned or left to decay. So there's a lot of interest in using forestry waste in biomass plants.

But Debbie Hammel of the Natural Resources Defense Council says, "I think if you're talking about waste, it's important to define what you mean."

"If you take too much of that residue out of the forest, you're going to have an impact on the forest floor, the fertility of the soil, erosion and potentially wildlife habitat."

Hammel says there's a major debate over how much thinning is good for a forest. So, she worries that a larger biomass industry would create incentives to over-harvest forests. That's why Hammel says not all biomass is equal – and why waste like almond shells should be used before forest cuttings.

"There is a role for biomass done right, but it's a smaller role I think than some people imagine," says Hammel.

Looking ahead, Hammel says the next thorny issue is calculating the greenhouse gas emissions from biomass plants, which can be tricky since the fuels come from a number of sources. That's something the federal Environmental Protection Agency is reviewing now.

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Wildfire ripped through this area of forest, which was infested with Sudden Oak Death. Does infestation with SOD make wildfires burn with more intensity? Photo: Kerri Frangioso.

From Oregon to Big Sur, potentially millions of trees have been killed by Sudden Oak Death, or SOD. In 2006 and 2007, researchers from UC Davis set up a large-scale study in the coastal forests near Big Sur to examine the spread of the disease and its impact on forest dynamics. The area was one of the first to be affected by SOD. Members of the Rizzo Lab at UC Davis had established 280 plots across the region, carefully counting and measuring each tree and checking for SOD infection. Then, in June 2008, the Basin Complex Fire ripped through Big Sur, burning over 95,000 hectares of forest. By the time the fire was contained, over a month after it began, one third of the team’s plots were crisp and blackened.

While the fire burned, news media and firefighters assumed that areas of the forest infested with SOD would burn more intensely—all the dead oak trees would fuel the fire. But the natural experiment created by the overlap of the Basin Complex Fire and the UC Davis study allowed researchers to test whether SOD did in fact make wildfire worse. Their study will soon be published in the journal Ecological Applications; a preprint of their paper is available here. What they found was not what the news media or the firefighters predicted.

Andrew Molera State Park, the same plot as the top photo, before the Basin Complex Fire. Photo: Kerri Frangioso.

Invasion of the water molds
Sudden Oak Death came to California in the 1990s, probably on the leaves of a rhododendron shipped in for the nursery industry. The disease is caused by a water mold, called Phytophthora ramorum. It can spread short distances in splashes of water, and can potentially travel longer distances when water is blown about in storms.

Not all trees that are infected with the pathogen will die. Some species, like California Bay Laurel, do just fine. But California Bay is like Typhoid Mary—it serves as a host to the pathogen and allows it to spread to other, more susceptible species. The pathogen is fatal to tanoak and several species of oak trees. These species develop cankers on their trunks, which bleed out a thick, red liquid. Slowly, the bark around the entire circumference of the tree is affected; all tissue above this girdle dies, leading to the death of the tree.

A natural experiment
In 2008, Margaret Metz had just begun a new post-doc in Dave Rizzo’s lab. She was to work on the Big Sur project and analyze the data from the 280 plots to understand SOD impacts in the region. Her colleagues had spent months setting up the plots for their SOD study. They knew the size and location of every tree, whether it was standing upright and healthy (or newly infested with SOD), or whether it was dead and decomposing on the ground. When Metz found out her study site was burning, she was devastated. All that hard work—and all those trees—was going up in flames.

However, the dismay was short-lived. The team had a perfect pre-fire dataset. They just needed to census the plots after the fire, to get a rare comparison of the severity of fire in areas with and without SOD. This was an experiment they didn’t intend on doing—but drought and a dry lightning strike had made it possible. Dave Rizzo was able to quickly procure funding for the researchers to re-census the plots. “You could never do a controlled burn on that scale,” says Metz.

Where there’s SOD, there’s more intense fire?
News articles about the Basin Complex fire linked SOD to fire intensity, and firefighters reported that fires were burning more fiercely in areas with evidence of SOD. So when Metz and her colleagues analyzed their data, they thought they’d see that fires were more severe in plots infested with SOD. But that is not what they found. Their data showed that plots with and without SOD showed no difference in fire severity. They quantified fire severity using something called the Composite Burn Index. It takes into account the effects of fire on the ground, as well as in the shrubs and trees. Composite Burn Index did not differ between plots infested with SOD and plots without SOD. The popular assumption, that SOD makes wildfires burn more intensely, was wrong.

Dead tanoak along the Big Sur Highway. Photo: Karl Buermeyer, COMTF.

However, Metz and the team could dig deeper into their data. From their pre-fire data, they knew whether SOD had infested the plots recently, or whether SOD had been there for some time. It can take several years for a tree to die from SOD. When trees are first infected with SOD and die, their leaves turn dry and brown, and they remain on the tree for a year or more. Later, the branches fall to the ground, and eventually the whole trunk falls over. The fuel created by newly infected trees and trees that have been infected for several years is quite different. Metz and her colleagues found that in plots that were newly infested, plots with more dead biomass (or fuel) burned more intensely. In plots that were infested some time ago, the amount of biomass was not related to the intensity of the fire. They suspect that crisp brown leaves on newly infected trees allow the fire to burn high in the canopy. In plots infested long ago, the dead trees are on the ground; in this case, the fire damages the soil and the tree roots, which makes slopes vulnerable to erosion from mudslides. The conventional wisdom about SOD and fire was not quite right, but there was some truth to it—it just depends on when the forest was infested with SOD. Newly infested forests burn with more intensity than un-infested forests or forests that were infested some time ago.

Future forests
It has been almost three years since the Basin Complex Fire burned up Metz’s plots. Now, she and her colleagues are looking to see how the forest recovers—from the fire, and from SOD. Maia Beh, a grad student in the Rizzo Lab, found that of the plots that had SOD in the pre-fire surveys, only 20% still have it today. They’re not sure whether it’s because of the fire, or because there have been two years of drought. The pathogen, P. ramorum, is dependent on water, and doesn’t do well in drought conditions. They’re looking at plots that did not burn up in the fire to see whether the decline in the pathogen is due to drought, fire, or some combination of the two.

Though the incidence of the pathogen has declined on land, it is still present in almost all the watersheds in the area. And, last year we had late rains, extending through spring into the early summer. Late rains with warm temperatures create conditions that are ideal for the pathogen, says Metz.

With continued careful sampling of those 280 plots—and maybe a few more unintended natural experiments—Metz and her colleagues will learn how forests recover from both fire and SOD.

Learn more about SOD
To prevent the spread of the pathogen P. ramorum, take steps make sure it isn’t hitchhiking on your boots. Clean your boots into the buckets of diluted bleach that you might find at trailheads, or spray your boots down with Lysol.

Take part in a SOD-blitz, a citizen science project. Learn more about SOD and help figure out where the pathogen has spread, with UC Berkeley plant pathologist Matteo Garbolotto. You can see Garbolotto on the QUEST video Plant Plague: Sudden Oak Death.

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The Truckee River Canyon. Credit: Michael Conner.

Natural capital isn't something we hear about very often, and it certainly isn't a new idea. Aldo Leopold and other conservationists recognized the role that natural ecosystems play in our lives as early as the 1940's. But understanding and measuring that role hasn't been easy. That's where the Natural Capital Project comes in.

The project focuses on ecosystem services – the natural processes that ecosystems provide and humans benefit from. Those include how forests filter our drinking water, how wetlands provide protection from storm surges, and how bees and other pollinators support our agricultural industry. While these services may not be the first thing you think of when it comes to nature, researchers are discovering that they're vital to human health and decision makers are starting to factor that it.

A few examples:

In the 1990's, New York City's water quality dropped below EPA standards. The obvious option was to built a new water filtration plant – with a hefty price tag: $6-8 billion for construction and $300 million in yearly operating expenses. Instead, the city decided to invest in the natural processes that help keep water clean. That meant looking upstream to the Catskills watershed where intact ecosystems could help filter the water. The city bought land upstream and improved sewer treatment plants – all at a much lower price: $1-1.5 billion.

In China, the Yangtze River Basin experienced devastating floods in 1998. Many believed the vast deforestation of the surrounding area had been the major cause, since it had eliminated the natural buffer that existed. Since then, the Chinese Government has adopted a system of ecosystem payments – giving subsidies to farmers to plant trees and preserve forested areas.  All in all, their program in budgeted in the billions.

The Natural Capital project has created an online tool known as InVEST that's freely available to the public. It allows users to map ecosystem services in any landscape. The project's co-found Gretchen Daily is hopeful that the tool will make it much easier for natural capital to be part of land use decision-making – especially in countries where development pressures are strong. "It's stunning to see how rapidly things are changing globally. We're losing trillions of dollars of value in natural capital in the form of rain forests and other key natural assets" Daily said. The project is already working with the government of Colombia to use InVEST and to improve their resource permitting process. You can read more about where else they're working here.

Listen to the Putting a Price on Nature radio report online.

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And how this metamorphosis saves Monkeys!

Colombia: a beautiful country, with incredible forests and diverse wildlife, but like many other countries, a trash problem. With no formal trash collection system, the forests and villages suffer from scattered plastic bags, endangering wildlife and creating a mess on village streets. One such village was Los Limites, until they came up with a most transformative solution: Eco-Mochilas!

The Eco-Mochila project was invented by the organization Proyecto Titi (Project Tamarin), a dynamic conservation program that combines field research, education, and community programs in an effort to protect the endangered Cotton Top Tamarin.

An Eco-Mochila is a bag made from crocheting 100 plastic bags into a colorful beach bag or purse. The innovative woman who create the bags are called the Asoartesanas. They encourage villagers and school children to collect plastic bags and as they go door to door to collect, they educate the people about their local wildlife. Then, they cut the bags into strips and begin their craft.

Eco-Mochilas are sold throughout the world at various venues and bring in a suitable salary for an artist. Of course, the collecting of thousands of plastic bags has other benefits: a more beautiful village, and a forest clear of trash, which makes a certain one-pound monkey very happy.

The endangered Cotton Top Tamarin is found only in the forests of Colombia. Deforestation and capture for the pet trade are the species' greatest threats. The Eco-Mochila project creates sustenance for villagers, an alternative to using the forest for such, and of course, offers a cleaner forest for all wildlife.

The program has been so successful that the Asoartesanas have trained people from other countries to begin similar project in their communities…

And in case this is important to their case, eco-mochilas are cute, come in different sizes, can be personalized, make great presents and are water resistant. I have three!

Click here to purchase an Eco-Mochila and help Cotton-Top Tamarins; and come visit the Tamarins at the Oakland Zoo anytime.

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