Rangelands and Climate change

Ecological sites are the basic component of a land-type classification system that describes ecological potential and ecosystem dynamics of land areas. We interviewed Dr. Joel Brown, current leader of the Natural Resources Conservation Service’s National Ecological Site Team, to learn more about ecological site descriptions, transitions and transformations, and some thoughts about rangeland ecology under a changing climate. Image Credit: USDA Photo by Lance Cheung.

Relevant Links:
Ecosystem Dynamics Interpretive Tool (EDIT)

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Come Rain or Shine affiliate links:
DOI Southwest CASC: https://www.swcasc.arizona.edu/
USDA Southwest Climate Hub: https://www.climatehubs.usda.gov/hubs/southwest
Sustainable Southwest Beef Project (NIFA Grant #2019-69012-29853): https://southwestbeef.org/ 

Transcript

[00:00:00] Emile Elias: Welcome to Come Rain or Shine Podcast of the USDA Southwest Climate Hub 

[00:00:05] Sarah LeRoy: and the USGS Southwest Climate Adaptation Science Center, or Southwest CASC. I'm Sarah LeRoy Science Applications and Communications Coordinator for the Southwest CASC.

[00:00:17] Emile Elias: And I'm Emile Elias, Director of the Southwest Climate Hub.

[00:00:21] Here we highlight stories to share the most recent advances in climate science, weather, and climate adaptation and innovative practices to support resilient landscapes and communities. 

[00:00:33] Sarah LeRoy: We believe that sharing some of the most innovative forward thinking and creative climate science and adaptation will strengthen our collective ability to respond to even the most challenging impacts of climate change in one of the hottest and driest regions of the world.

[00:00:55] The contents of this podcast are for informational purposes only and should not be interpreted as endorsement for any of the products, technologies, or strategies discussed. 

[00:01:07] Emile Elias: Today we speak with our friend and colleague, Dr. Joel Brown, about Rangelands in the Southwest. Over his 45 year career, Joel has become one of the most influential Rangeland scientists of his generation.

[00:01:20] Joel is currently the leader of the NRCS National Ecological Site team and has devoted his professional career to critical analysis of the basic tenants of the Rangeland profession. Joel's scientific accomplishments, including over 100 published papers, have provided visionary leadership to the Rangeland community.

[00:01:41] He has contributed to our understanding of the mechanisms of woody plant encroachment, climate change effects, drought management, and ecosystem service perspectives on Rangelands. Since the USDA Climate Hub Network was formed in 2014, Joel has served as the senior science advisor for the Southwest Climate Hub providing guidance on climate adaptation strategies.

[00:02:05] Joel, thanks for joining us today. Well, as I mentioned in the introduction, you are a Rangeland ecologist by training, and I'm curious about what led you to study Rangelands? 

[00:02:17] Joel Brown: Well, like everyone else in their career, that path was long and tortuous. I was raised on a livestock grazing operation in southern Oklahoma, and I worked with a lot of old school cowboys.

[00:02:31] Those associations led me to believe that I needed a plan that included a lot less writing, roping, and wrestling animals, especially as I got older. I was also around for the beginnings of Earth Day in the 1970s, and I knew I wanted to pursue the ideas of protecting the environment and continue to work in agriculture.

[00:02:52] So the field of Rangeland management seemed like a perfect fit for me. Fortunately, I've been lucky enough to be around a lot of people that felt the same. 

[00:03:03] Emile Elias: Thanks Joel. I didn't realize you grew up with some old school cowboys. Have some of those in my past as well. My grandfather and his friends, so yeah, that could lead you to this kind of study. 

[00:03:19] Joel Brown: And I got a lot of nifty sayings out of it. 

[00:03:24] Emile Elias: Excellent. Well, we'll try to circle back to those at the end. So throughout your career, you became well known for your work with ecological sites and now serve as the leader for the National Ecological Site team. Not all of our listeners are familiar with ecological sites, so can you please give us a quick overview of what an ecological site description is and how it's used?

[00:03:48] Joel Brown: Sure, and I'll, I'll try to condense, uh, over a hundred years of work into one or two minute answer. Ecological sites really are just a current expression of some longstanding ideas and practices in land management. There are subdivisions of a larger landscape based on predictable soil and climate properties.

[00:04:11] Of course there's a whole host of complexities, but the idea has always been to be able to create field scale maps with verifiable attributes that can be used as a reliable and repeatable basis for planning and management. Ecological site descriptions really are the documentation that backs up those ideas and those map units, including soil properties, rainfall distribution, growing conditions, and especially how all of those things interact with management to produce what we expect from land.

[00:04:48] These descriptions, there could be a mix of raw data, science based logic and management experience. And the job of all ecological site specialists and ecological site developers is really to figure out how to make that information available as quickly and as easily as possible. 

[00:05:08] Emile Elias: You alluded to this a little bit in, in saying that this is a hundred years of information and research, but when did the ecological site description concept emerge, and did it replace a different or alternate way of viewing range lands, and is the concept applied to rangelands globally?

[00:05:27] Joel Brown: Good questions. Like I said earlier, this is just the current version of some longstanding and really constantly evolving practice. In the early 20th century, scientists and land managers collaborated to develop ways of combining the knowledge into management principles and tools. At that point, unfortunately, they were limited by just a, a short history, both of experimentation and observation, and it was difficult to predict at a land management time scale the dynamics that they were interested in.

[00:06:02] Over the years, as we've made more of those observations and done more of those experiments, we've learned that ecological behavior is much more complex and much more unpredictable than we thought. And as those observations and experiments started to accumulate in the late seventies and in the early eighties, we started to call these non-equilibrium dynamics.

[00:06:25] To reflect how the behavior of those ecosystems were driven by highly variable weather, interacting with recurring, but hard to predict disturbance events like drought, grazing, fire, and so forth. But one of the really great things about that transformation in our thinking was that it was the result of international collaborations and included people from Africa, Australia, North and South America, Europe, and Asia.

[00:06:56] As these ideas began to take hold, we were able to benefit from simultaneous advances in data management, computing, remote sensing, and all those other fields of science, and we started to create new ways of communicating and managing our information. The emergence of this new science has become the standard for Rangeland ecology and management globally.

[00:07:22] Sarah LeRoy: Excellent. Thanks Joel. And it's really nice to meet you. So I'm curious, how could a land manager find the ecological site description of an area where he or she works? 

[00:07:32] Joel Brown: Thanks Sarah. And likewise, nice to meet you and get to know you a little bit. All of these advances, and in particular, the advance advances in information system science have really led us to much better ways of organizing, analyzing, synthesizing, and importantly communicating ecological site information.

[00:07:55] Anyone with a computer and an internet can find information for a specific piece of land using the Ecosystem Dynamics Interpretive Tool or EDIT. Just Google "EDIT Jornada" and you'll find lots of information about the science behind ecological sites and all of the information available for the whole country of the United States. A particular state, a county, or all the way down, even to a specific field level.

[00:08:26] Each ecological site description will contain information about its regional and landscape context, where it sits and what's around it. And what soil, what climate, what hydrology, the ecological dynamics and the land management interpretations that are associated with the site itself. 

[00:08:49] Sarah LeRoy: Great, thank you. And we'll make sure to include the link for EDIT in the description for the podcast episode. So if there isn't an ecological site defined for a particular area, what would you recommend that someone do? 

[00:09:03] Joel Brown: Well, there's a couple of things that you can try. Currently, we have more than 12,500 separate ecological sites in that EDIT information system, so we have a lot of descriptions that we've accumulated over the 60 years that we've been doing this.

[00:09:23] If there's not one available for a particular piece of land that you're interested in, you can search that database and find similar climate, similar soil properties, or anything that would help guide you to select the one that's most appropriate for the particular piece of ground that you wanna work on.

[00:09:44] You can also contact your local NRCS office or your local BLM if you're working with BLM land. 

[00:09:51] Sarah LeRoy: Great. So I think we have a pretty good understanding of ecological sites at this point, and so I'm going to transition us to talk about state and transition models. Could you explain what state and transition models are, how a person might use them, and then maybe even walk us through an example of someone using a state and transition model for an ecological site.

[00:10:15] Joel Brown: Probably the most important thing in that ecological site description is that state and transition model. It's a graphical description of how that particular ecosystem behaves in response to changes in weather, natural disturbances and most importantly, management. It's how a user can inventory their current status of a particular piece of land, what options they have for managing in the future, and they can select from multiple options for changing land use and deciding what management practices are necessary to achieve their goals.

[00:10:55] The current conditions and potentials are referred to as the ecological state or states, and the actions necessary to make a state change are called transitions. Those transitions have information about specific practices or actions. What it costs to achieve that transition and how long it will take.

[00:11:20] An important part of every state and transition model is the ecological state that we use for comparisons. We call that the reference state. 

[00:11:29] Emile Elias: Thanks Joel. And to add onto that, how do you determine what the reference state of a site is? And for our listeners who might not be familiar with the term, can you explain what it is?

[00:11:41] Joel Brown: Emile, you really got to the hard questions quickly. Determining a reference state is probably the hardest thing that we do as ecological site specialists. As I said earlier in the, in the early 20th century when we assumed that land dynamics were a lot less complicated and more deterministic we just looked around for a piece of ground that we thought had been protected from disturbances like fire grazing, plowing, and then measured some soil and plant attributes, and then we can compare other locations to that.

[00:12:17] But as we've learned more about those dynamics, including the effects of a constantly changing climate, we've realized that our interpretations of what was happening on those small, isolated, protected pieces of land really could be very misleading about what would happen in the future. Now, we tend to think of a reference state as a broader set of conditions that give us the most options for management of that site.

[00:12:49] Then we try to capture that range of soil and plant properties over time to give us a more robust idea of the ecological processes that are going on, on that site. It gives us a much better way to deal with variability and it helps to avoid misinterpretations of what's happening. 

[00:13:10] Emile Elias: Thanks, Joel. Yeah, that's, that's really helpful.

[00:13:13] Sorry for jumping into the difficult questions, but I'm gonna do it again. With the climatic changes that we're experiencing and we'll continue to experience in the future, do you think the ecological potential for some of these sites has already changed or will change in the future? 

[00:13:30] Joel Brown: There's no doubt they're changing.

[00:13:32] That is one of the fundamental principles of non-equilibrium ecology, and that is that the past is not necessarily a very good predictor of the future, and just because something was there in the past, or even because it currently occupies that site. That doesn't mean that that's what's gonna return after a disturbance like drought or fire.

[00:13:58] We have examples and lots of examples of places where things like depth, the water table has changed, where invasive plants or animals have altered the ecological processes so much that a new and different system has emerged and what's out there is different than what we thought should be out there and how it got there.

[00:14:21] Uh, how that system behaves is different than what we thought. Obviously, the changes in climate that have already occurred and are happening now are gonna be some of those events that forever change these ecosystems. 

[00:14:35] Emile Elias: Thanks, Joel. As you know, parts of our region have been enduring drought conditions for several decades, and this makes me wonder about landscapes being permanently changed or altered due to water scarcity or thresholds or tipping points with the possibility that some areas might change or transform into something functionally different from what they've been in the past.

[00:14:59] And so I wonder how can we mindfully plan for those transitions. If we're anticipating things to change, how can we plan for that? 

[00:15:10] Joel Brown: And Emile, be sure and tell me before we get back to the easy questions, because these just seem to keep getting harder. Documenting the type of changes that you have just asked about, it's really been a large part of what Rangeland ecological research has been about for many years. And you know, we've got a huge litany of these. There's no better example than the widespread conversion of extensive native grassland to shrub dominated ecosystems over the past century. Although the dominant land use grazing didn't directly cause that shrub increase those highly complex interactions of livestock as enhanced agents of sea dispersal, suspension of the fire regime due to lack of fuel consumed by grazing and a reduced production from drought that led to increased shrub populations has changed regardless of whether those grasses were the, the desert grasslands that we're familiar with here in the Southwest, or the mid or tall grass prairies that we're familiar with in the central part of the country, and whether those shrubs were native or introduced.

[00:16:24] It's just a common thing that's happening all around the globe. And it's probably that one single thing that forced us to adopt a more non-equilibrium approach to our research and management that we've been talking about.

[00:16:42] Sarah LeRoy: Excellent. So, Joel, do you have any solutions that you would recommend to ranchers in the Southwest, given drought and climatic changes that are happening in the region that you just highlighted?

[00:16:55] Joel Brown: I don't know that I have any solutions. Maybe some suggestions that people could use to design their own personal solutions that'll work for their land and for their operations. I think the main thing is to really get a realistic idea of how much conditions can vary on their operation and make that a quantitative piece of information that's part of it, that inventory process.

[00:17:26] When we can then design an economic approach to livestock production that takes that variability into account it's, and especially here in the Southwest, it's very likely gonna include some years that require drastic stocking rate reductions. After all, we have some years that we produce very little forage, and those reductions are gonna be necessary to avoid land degradation and poor livestock performance.

[00:17:59] In those cases, you're either gonna have to stockpile forage, buy feed or destock. There's just no way around that particular decision. We've got century long records of how much production can vary on Southwestern Rangelands, but I don't think we have yet come up with a livestock management system that reflects that level of variability.

[00:18:26] It may, when we do, it may include new kinds of livestock, new kinds of production systems, or maybe just an adjustment of our expectations. 

[00:18:38] Sarah LeRoy: Thank you. So similarly, thinking about Rangeland scientists, you know, as they continue to analyze and evaluate the landscape, do you have any advice, or I guess I would say suggestions that you might offer them?

[00:18:52] Joel Brown: Yeah, we've got a a century of really good work in places like Santa Rita, in south of Tucson and here at the Jornada, where a lot of people have done a lot of good work for a very long time. And we're at the point where we understand those basic relationships well enough, and we've got a lot of historical observations that we can draw on to develop some new ideas.

[00:19:19] Most importantly, we know that nature is not very forgiving. And our mistakes, whether they're economic or ecological, can cascade and change things for the foreseeable future. Given the context of climate change that we're facing, I don't think we can assume that anything is off limits or out of bounds for research work.

[00:19:44] We have to be more creative. We've seen over the last 20 years or so that land managers really also wanna be part of that research and they are exceptionally creative. So I, I think the, the two things are just be more creative in searching for solutions and include people in those solutions. 

[00:20:09] Sarah LeRoy: That's perfect. Thank you. Great answer. So I'm gonna shift gears just slightly and talk about the Chicago Climate Exchange, which is you were a part of, of a team working with, with the Chicago Climate Exchange, which ended in 2010. So I'm wondering if you could tell us a little bit about that exchange and how the past might inform current efforts related to specifically carbon sequestration and rangelands.

[00:20:35] Joel Brown: Well, first of all, I was part of a very large group of people that were involved in that, that went all the way from commodity economists, social economists, ecologists, agronomists, and I certainly learned a lot and I think everyone else did too. First, I think the ranchers that were involved, and that was a group of ranchers that actually signed up with the Chicago Climate Exchange, and in exchange for managing land using certain practices, they got an annual payment. 

[00:21:14] I think they learned a lot about what an ecosystem services market on Rangeland would look like, and they learned how to navigate that market to help achieve their enterprise objectives. Second, the aggregators, and this is a group of people that we're not really that familiar with in traditional Rangeland management or even in traditional agriculture, but that's the people who organize those land based credits and figure out how to deliver them to a market.

[00:21:47] Those aggregators learn how to manage risk across a regional project in a highly variable climate that involves lots of participants. And that was certainly no small task. The exchange, the Chicago Climate Exchange learned how to keep overheads low and to still get credible estimates of land-based ecosystem services.

[00:22:12] In our particular case, this was carbon as an eco, carbon storage as an ecosystem service, but there's lots of other ecosystem services out there that we can apply that knowledge to as we go forward. And finally, I learned, and I hope other scientists learned how important it is to be able to come up with accurate estimates of potential carbon storage or potential changes in other ecosystem services that people are interested in, and to develop realistic ways to make those measurements of that change and put that in a context where we can keep everyone informed in that market, how to value those transactions. 

[00:22:58] Sarah LeRoy: Great. And we always like to end our episodes by asking our guests what gives them hope. And so in thinking about Southwestern Rangelands and everything that we've talked about today, what gives you hope for the future?

[00:23:12] Joel Brown: Finally an easy question.

[00:23:15] Sarah LeRoy: Oh, easy, Okay. 

[00:23:17] Joel Brown: Yes. 

[00:23:17] Sarah LeRoy: Usually that's a, this is a hard question.

[00:23:19] Joel Brown: Oh, it's always easy to talk about your hopes. I'm constantly amazed by the exceptional skills, the enthusiasm, and the creativity of our new young scientists. As well as, you know, over the past decade or so, we really have emphasized that we want to increase the diversity of people that work in this field.

[00:23:46] And I think that increasing diversity has brought in a whole new wave of new ideas and new ways of looking at the world. And that's just has fueled our creativity. I think for people that are, are mid-career and, and further along in their career, the biggest challenge right now is to figure out how to encourage and capture that creativity so that we can take advantage of it in the science. That's an easy question. 

[00:24:19] Sarah LeRoy: Well, I'm glad we could end on an easy question. Well, thank you very much Dr. Joel Brown for joining us today and yeah, thank you. 

[00:24:28] Joel Brown: Thank you.

[00:24:33] Emile Elias: Thanks for listening to Come Rain or Shine, podcast of the USDA Southwest Climate Hub 

[00:24:38] Sarah LeRoy: and the USGS Southwest CASC. If you liked this podcast, don't forget to rate or review it and subscribe for more great episodes. A special thanks to our production crew, Skye Aney and Reanna Burnett. If you want more information, have any questions for the speakers or would like to offer feedback, please reach out to us via our websites.