New maps assess health of sagebrush ecosystems across the West

Vast expanses of the American West, including parts of Central and Eastern Oregon, share a unique ecosystem characterized by sagebrush, wildflowers and a wide array of perennial grasses. This “sagebrush sea” is one of the largest contiguous ecotypes in the U.S., but it faces increasing threats from wildfire, invasive species and development.

A new tool aims to help land managers quickly assess the health of these vast regions. Conservation groups, state and federal agencies and local leaders partnered to create digital maps that provide a broad view of where sagebrush ecosystems are thriving and where they hang in the balance.

Anya Tyson is the Oregon Sagebrush Sea Program Director for The Nature Conservancy, which helped create the maps. She joins us to share more.

Note: The following transcript was transcribed digitally and validated for accuracy, readability and formatting by an OPB volunteer.

Dave Miller: This is Think Out Loud on OPB. I’m Dave Miller. Vast expanses of the American West, including parts of Central and Eastern Oregon, share a unique ecosystem characterized by sagebrush, wildflowers and a wide array of perennial grasses. It’s known as the “sagebrush sea.” It faces increasing threats from wildfire, invasive species and development.

Now, a new tool could help preserve these lands. It was created by conservation groups, public land managers and local leaders to provide a broad view of where sagebrush ecosystems are doing well and where they’re in serious trouble.

Anya Tyson is the Oregon Sagebrush Sea Program Director for The Nature Conservancy, which helped create the maps. She joins us now. It’s great to have you on Think Out Loud.

Anya Tyson: Thank you for having me. It’s good to be here.

Miller: What kinds of plant and animal species does the so-called “sagebrush sea” support?

Tyson: There are thousands of shrubs, wildflowers, grasses, insects, small mammals, rabbits, rodents, badgers, and getting up to the big exciting ones, beautiful pronghorn antelope, mule deer, bighorn sheep, coyotes, mountain lions, bobcats, and hundreds of bird species rely on this ecosystem. And beyond the critters and the plants, human communities really thrive in this ecosystem. Many of our rural towns in eastern Oregon are inseparable from the sagebrush sea, via ranching and recreation. And then there’s Indigenous communities and Native nations whose cultural identities have been shaped by and continue to shape the landscape.

Miller: Can you give us a sense for the scale of these landscapes?

Tyson: Across the Western U.S. and the Intermountain West, I think of this gray-green sea stretching from the Cascades all the way to the Rockies, stretching essentially from the Canadian border all the way down to Arizona and Utah. And in Oregon, about one-third of the state is characterized by this sagebrush ecosystem.

Miller: I mentioned this briefly in my intro, but it’s really worth dwelling a little bit more on this. What broadly are the challenges that this vast landscape [is] facing right now?

Tyson: The big ones are invasive annual grasses. European settlers accidentally brought these “get rich quick” species of grass that outcompete and create a lot of flammable fuel out there. And that is really a challenge. It makes less good forage for wildlife and livestock, it really changes wildfire behavior and it can create almost monocultures of itself. These grasses have very evocative names like cheatgrass and medusahead. Experts estimate almost 70% of the degradation across the sagebrush biome, that’s the primary driver.

The other big ones are native conifer species. We love our old growth junipers, they’re very important, but they are overrepresented. There were several factors that led to conifers encroaching into areas that should be grasslands and shrublands, and turning them into woodlands, and a whole host of issues that goes along with that. And both of those things interact with wildfire, changing patterns in wildfire. And a little bit of human development. With that set of four, you have the biggest threats for the biome.

Miller: So those are the threats. Let’s turn now to the tool that you and others helped create to better respond to those threats. What’s the big idea behind this new mapping tool?

Tyson: The idea is it’s supposed to make things just a little bit simpler, so we can move out of decision paralysis, and we can move and respond to threats at the pace and scale that they’re occurring. Essentially, we’ve really honed in on this, you named it in your introduction, I touched on it. This is a really big landscape. And it’s not very peopled. There’s incredible people that live out there, but there’s not a ton of them. So you cannot walk every acre out there and create a detailed plan based on a specific list. If you set out to do that, your intention would be good. But the backlog of acres that you would never get to and [that] these threats are moving across, you’d have made a choice of inaction.

Miller: I can imagine someone saying, “hey, I like the idea of a tool that makes things easier, but we need granular level detail.” You’re saying that it’s not humanly possible, given our resources, to get that kind of detail simply because of the vastness of the scale?

Tyson: We can’t do it for every acre. There are places, before you go take certain management actions, yes you absolutely need to get out on the ground and go see it. But to start the conversation with communities, with land managers, you need to start the conversation at a different speed and a different kind of elevation. And this tool helps people start the conversation and look at the big picture, and then weave in local knowledge and go down into the granular details where it’s going to make the most difference.

Miller: So what data do you have at the landscape level that you can use to inform these large-scale maps?

Tyson: The maps are built on satellite collected data that goes back to the ‘80s, which is really cool because we can look at trends over time. And this is coarse data. The models behind this, it’s based on data that is first filtered through the rangeland analysis platform, and sorts pixels in the landscape into different amounts of perennial grasses and forbs, and annual grasses and forbs, shrubs and tree cover.

Miller: Even a satellite imagery over time can tell you where there’s a preponderance of good perennial grasses and where there’s a lot of invasive annual grasses? You can tell that from a camera in the sky?

Tyson: Yes. You don’t get it right every time, but you can tell these patterns. And we know that, you can zoom in on a satellite image when you’re looking at Google Maps and see a tree. And similarly, in these grassland landscapes, you can see a sea of cheatgrass. It’s much blonder and it’s a different texture than a north-facing slope that still has perennial bunch grasses and shrubs on it. It’s a little bit blurred, it’s not perfect, and that’s where these other data sets come in. The maps are not meant to be a decision in and of themselves. But they are a starting point for discussion and it really accelerates the discussion to have that starting point.

Miller: Looking at the maps, we can see that Oregon has what’s categorized as a lot of “poor condition grassland.” Montana is full of “good condition grassland.” What’s the difference between these two states?

Tyson: Montana, you’re getting into the northern Great Plains, and you have more moisture and higher elevation. We have a more sensitive ecosystem here in the Northern Great Basin. It’s more arid and invasive annual grasses have a bigger leg up here. And often, wildfire conditions are more severe here. So it’s less that Montana has done a much better job of managing their habitats than Oregon has. Indeed, we’re just kind of a bellwether, we’re ahead of Montana. We have great opportunities still, where we have large chunks of good condition sagebrush, and we can keep it that way if we don’t chase our tail and only try to focus on where we’ve already kind of lost those important native plant dominance in the landscape.

Miller: You’re saying that we’d be chasing our tails if we focus on the places where we’ve already lost, in a sense, or where invasive grasses have beaten out native grasses. Instead, you’re saying we should focus on the places that are still working, that still look like they would have hundreds of years ago. Why? Why is it important to focus on what is hanging on, as opposed to trying to fix what we seem to have lost?

Tyson: I really appreciate you asking this question. It comes down to the simple folk wisdom of an ounce of prevention is worth a pound of cure. We do not have the resources, human or financial, to remove annuals where they’ve become dominant and reseed in perennials, because we’re talking about millions of acres. But we do have the resources in an area that’s still in good shape to look for tiny patches of invasive annual grasses, to manage the landscape in a way that the perennial native vegetation has a leg up over the annual grasses.

So it’s just a much better use of our resources to keep areas that are in good shape [and] maintain them that way, with investment, with vigilance, than to try to resurrect an ecosystem that has thoroughly slipped, because it costs so much to physically remove or chemically remove weeds once they’re dominant and try to reestablish vegetation in these arid landscapes. This ecosystem is defined by its extremely hot summers and its extremely cold winters, and you do not succeed when you plant seeds out there every year. So that’s the really difficult thing. [If] you need to bring back native plants from scratch, you have a really difficult task ahead of you. If you instead can sustain native plants that are already in place, it is much more feasible.

Miller: When you’re making this argument right now, are you saying this to people who are actually trying to plant native grasses? Because I feel like in the past we’ve had conversations explicitly about that. I’m wondering how much of a debate there is within the arid west conservation world right now about the best way to proceed, given limited resources?

Tyson: Well, I’m really glad you’re mentioning this. It is complex. There’s still very much a place for seeding native plants. But you might want to spend those resources in the middle of an area where you’re essentially plugging a hole. Like there’s a small hole of poor condition grassland in a larger matrix of good condition shrubland…

Miller: In my head, I immediately thought about a sort of half bald head and putting plugs there, as opposed to going to the place where someone is fully bald and trying to reseed that with hair.

Tyson: Sure, yeah. I love that. [Laughs]

Miller: Maybe this just says something about the way I think about myself, as opposed to the land. But please go on.

Tyson: I’m picturing the chia pet, with different amounts of hair.

This is not a prescriptive approach where it says, “forget about this huge chunk of the state where there’s a lot of invasive annual grasses.” It’s just different tools and different expectations, and wise use of resources across those landscapes. A great example is, you might really want to use your native seeds – of which there is a limited quantity of and we’d love to see more of them – but you might want to use your limited quantity of native seeds that are very expensive in a landscape that’s in better shape where you’re plugging these small holes. And you might want to use other hardier species, that aren’t native and are more cost-effective, in an area that’s been a cheatgrass monoculture for a really long time. You still might seed both areas because you might need to stabilize forage, you might need to provide wildfire resilience and protection for nearby communities. But you are using different costs of tools, knowing your neighborhood, and knowing what’s possible and what’s a worthwhile investment, with this really pragmatic backdrop of people have been working in this ecosystem for a long time and we’re still, across the American West, losing 1.3 million acres per year.

So that’s why there is this conversation, we got to do things a little bit different. We need to focus on keeping areas that are good in good shape and adjusting our expectation in certain areas that we can’t justify spending all our resources on right now. We know it’s not working.

Miller: Anya, thanks very much.

Tyson: Thank you! Thanks for the conversation and the fun images of bald heads.

Miller: [Laughs] You’re welcome. Anya Tyson is the Oregon Sagebrush Sea Program Director for The Nature Conservancy. She’s part of a team that helped create a tool known as Ecostate Maps that can be used to preserve these fragile ecosystems.

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