AoR 28: Sam Fuhlendorf Part 1, Managing Rangelands for Heterogeneity

"Six patches make you six times less likely to be entirely wrong". Diversity and variability drive rangeland health. Healthy rangelands provide an array of ecological and social goods and services. Resiliency describes the robustness of natural mechanisms that allow land to continue providing those EGS over time with and through disturbance. Disturbances are necessary processes to create botanical diversity, but also changing diversity, across space and time. Human-caused disturbances should avoid pushing ecosystems over thresholds, tipping points, into new degraded stable states. Dr. Fuhlendorf says scientists and managers should "embrace ecological humility" and assume we know less than we think we do. 


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>> Welcome to the Art of Range, a podcast focused on rangelands and the people who manage them. I'm your host, Tip Hudson, range and lifestyle specialist with Washington State University Extension. The goal of this podcast is education and conservation through conversation. Find us online at

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We're going to post a two-part interview with Dr. Sam Fuhlendorf about heterogeneity. The first part will include some principles in managing for biodiversity. And the second part will focus more on what the implications are for grazing management if we're managing landscapes for heterogeneity.

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My guest today on the Art of Range is Sam Fuhlendorf. Sam is at Oklahoma State University and is the Grundike chair of Wildlife Management. Sam, welcome to the show.

>> Thanks, Tip. I'm glad to be here.

>> As you might be able to tell, because my lips are a little cold, my southern accent comes out just a bit. I grew up in the Ozarks of northern Arkansas and initially came to the University of Idaho to study wildlife biology. I had done an internship with the Corps of Engineers there working with wildlife biologists doing habitat management, mostly patch burns focused on wild turkeys on the land that they owned around the two big lakes there in northern Arkansas, Norfolk and Bull Shoals. And I really enjoyed the integration of plants and wildlife and people. And when I got to the University of Idaho, I was introduced to rangeland ecology and it was more in line with my interest than I guess the version of wildlife biology that seemed to prevail in the Pacific Northwest. And at the time that seemed to be largely preserving wildlife populations by removing humans from the equation. And I liked the idea of range as being what seemed to be a truly integrative discipline that kind of put all of that together and didn't focus on one in particular. How did you get into wildlife management and end up in this professor position at Oklahoma?

>> Well, thanks, Tip. That's interesting. I didn't know all of that about you. I started school at Angelo State University in west Texas. And I had an interesting agriculture and I had a background in a lot of things outdoors. And I enjoyed traveling through the west with my father. We would fly fish and just enjoy the outdoors. And I found range to be the most attractive major during that time period. And eventually decided to go to graduate school. And I developed a real passion for large landscapes, and I never really had much of a background of wildlife in school. I was fortunate that eventually after working here at Oklahoma State for a while, one of the endowed chairs, the person in charge of it was well-versed. And in reality the best way to managed wildlife in this part of the world is to do range management on private land. So they had a strong connection and were willing for that to be a focus of the chair.

>> So how long have you been here at Oklahoma State?

>> 22 years.

>> Well, I don't know whether you're like me. I feel like the longer I go, the fewer pat answers I have. And I thanked you before, but I'll thank you again on the air for blowing up my brain with these papers about heterogeneity. I've been studying rangeland ecology for about 25 years now if you count the start of my undergraduate work. And yeah, I feel like I just took another giant leap away from easy answers. You say in the book chapter that you wrote on heterogeneity as the basis for management that this idea has only recently become appreciated as a component of ecological systems, and adopting it as a guiding principle for ecosystem management has been slow. Obstacles to heterogeneity-based management and policy stem from problems associated with understanding the concept, inconsistent definitions and measurement as well as a general affinity for homogenous landscapes. I feel like that sets it up pretty good. So I'd like to talk about some general principles on why heterogeneity is important and we'll need to start by defining heterogeneity. How it relates to rangeland resiliency. I sort of feel like resiliency is rapidly becoming a word kind of like sustainability, where it starts to lose meaning. So we'll try to define it. A bit about grazing management, which is where I'd like to end up. So let me make an attempt at a summary of what I think I understand about what you've said, and then we'll get into the weeds. I would say that everybody agrees that healthy range lands provide a wide array of ecological and social goods and services, that rangeland resilience describes the robustness of the natural mechanisms that allow land to continue providing those goods and services over time, both with and through disturbance. That disturbances are necessary processes to create botanical diversity, but also changing diversity across space and time. And that disturbances that we impose on the landscape by human activity should avoid -- it could be beneficial in terms of prompting that spatial heterogeneity, but should avoid pushing ecosystems over these thresholds, these tipping points into new degraded stable states. And I guess that would be more a persistent disturbance rather than -- I remember in one of my ecology classes at University of Idaho somebody somewhere distinguished between press disturbances and pulse disturbances. And that really stuck with me. I think the example that was given was that a press disturbance would be like a poorly built dirt road next to a stream. And the constant sediment input into that stream as a press disturbance fundamentally changes the nature of that stream because it never goes away. But then something like a rain on snow event where you have a giant pulse that, you know, blows through the riparian system, you know, ripping out trees and reshaping stream banks, and then goes away. There's enough resiliency to recover from that as long as you've got the right plant communities and processes in place to rebuild after that pulse. And so with human-caused disturbance, my take is that we want to offer things that are more like a pulse than a permanent press, that change things long-term. Now you can take that apart.

>> Wow. Well, shoot, Tip, it sounds like you have the story and we can just end this podcast right now. No, I mean, you're right about everything you said. I feel like I agree with the terminology challenge, and even heterogeneity is sometimes -- you know, it's like you make -- somewhere a word appears and next thing you know we've all distorted its meaning and no one really knows what it means. But in general, I guess the short answer to all of that is that in my mind I agree with you that I don't know as much as I used to know. I jokingly say that when I was working on my PhD, I knew exactly what an ecosystem was, and no I have no idea. I struggle with that all the time. And it's let me to sort of embrace an idea of ecological humility. And the idea being that if you manage for say six different vegetation types, then you're six times less likely to be entirely wrong. And that's actually more attractive than it sounds. And that sort of contrasted to the sort of engineering perspective where we know exactly what we want the world to be and we make all of the world look like that. So I struggle with those in the same ways probably that you do, because we have similar backgrounds. But I do think that one important context is to think about where did this discipline come from, and where are the principles that we now think are normal? Where did they come from? And what was the context of those at the time? And I tend to think of that, and I was fortunate in my graduate career to be around people that had a good historical perspective and could sort of tell me what was Dykstra House actually talking about? And in fact, Dykstra House was in the building when I first started graduate school. And you know, so a lot of those things that seem incorrect today are just in a different context. There's a reason that they did that and came up with the principles that they came up with. And it's just that some of our desires from rangelands have changed. And some of those principles may not apply as uniformly as they once did. So for example, sort of the range condition argument that you know, if you reduce stocking rates, you can get an improvement in the plant community. And that's fairly linear. A lot of that was developed in the context of not having a range profession really at the time. And that a lot of land was just really heavily grazed. And so in today's standards it's grossly oversimplified, but in reality at the time that simplification may have been essential just to get a message across.

>> Right. There's often kind of a social lag time to react to, you know, real abuses of land. And there was real degradation that happened, especially in the cattle boom in the late 1800's. And I guess the movement toward a do-no-harm grazing management policy or paradigm logically came out of that. Where really the only good option was to reduce cattle numbers and cause improvement. And it's assumed that that causality would hold true, you know, all the time.

>> Right. And it largely doesn't. And I remember when I first started out, the argument was the solution to everything was reducing stocking rate. And often that is a solution, but you know, it's not going to cure the fact that your grassland turned into a juniper woodland that's not going to go back by reducing stocking rate.

>> Right, or the idea that removing all the animals permanently would take us back to some pre-Columbian ecological Nirvana.

>> Exactly.

>> That probably didn't exist.

>> Exactly. It almost certainly didn't exist.

>> Yeah. Well, one of the big ideas that I feel like is foundational for managing for heterogeneity is that variation in nature is important, that that's the driver. And it's not just an obstacle to overcome with management effort to get us toward what you called the middle, you know, managing toward the middle, managing toward the mean. Can you talk about that a bit?

>> Yeah, you know, one way that I often talk about this is to beat up on my own profession which is doing scientific research. And I often point to the fact that most of our scientific paradigms came from something similar to an agronomy farm sort of experimental design where the goal is to remove variability. Except for the variability associated with say the fertilizer rates on different plots.

>> Right.

>> And so the take-home from that from a scientist is that if you want to exist in that culture, then you have to find a way to deal with variability, and the way you deal with it is you get rid of most of it. Which led to a lot of really small-scale studies that led to what I argue is a fairly simplified understanding of nature. And I would argue -- I mean, there are some really -- just as a disclaimer, we did acquire some really good knowledge from those studies, and they still are important. They just aren't really embracing the idea that we need to understand variability in space and time. And it seems like we even started to understand that we need longer-term studies before we started to understand that we actually need larger-scale studies. And of course it's really hard to do a large-scale study. So that aspect is that science hasn't done us any favors in trying to understand variability. But then on top of that, I like to point out that the public doesn't really deal very well with variance. And we've even done some social studies where we partnered with real social scientists and did surveys and looked at whether people were comfortable with heterogeneity or not. And you know, just even practical examples, I always tell the joke that I was mowing my yard and thinking about this one day, and I decided it was ridiculous that I was mowing one grass species all at the same height weekly, exactly. And I might have been having some adult beverages. So I decided to raise and lower the mower sort of randomly and do some designs in the yard and try and start a new trend. But needless to say that -- well, let's just say I had to remow the yard. I learned that the public does not really appreciate heterogeneity. So it's not just in range management. It's actually complexity is something hard to deal with. And it seems like at least in European cultures we don't enjoy heterogeneity necessarily. And we like our parks that have edged sidewalks.

>> Right. So we try to make our rangelands look like an English lawn.

>> Exactly. Exactly.

>> Yeah, this might have been something that I heard you talk about, the Society for Range Management Conference a couple years ago. The idea that there's something lost in translation is we do research at the scale of your kitchen tabletop and then extrapolate that to, you know, range management units that are the size of a county in much of the east.

>> Right. And you know, I think you can look at almost any parameter of interest, animal behavior or fire behavior or anything like that and you can see that if you study that at really small homogenous scales, that you run into problems. Or you might draw conclusions that aren't exactly correct. And you know, an example of that was when I first started this whole patch fire and grazing animals can go where they want, the seteris parabis studies, I ran into trouble from scientific reviewers that, you know, this treatment is neither burned nor unburned. Because you only burned part of it, so we don't know what to call that.

>> Right.

>> And I said, "Well, how about rangeland?" So it seems like that we're well-rooted in sort of this unrealistic perspective of strongly controlled studies.

>> Right. And trying to produce -- trying to get to. I feel like this is a problem both directions. You know, if you're trying to do any kind of natural resource study, one, it's really difficult to get to seteris parabis where you're holding everything constant except for the one variable you want to test. That's extraordinarily difficult to do, period, in the natural environment. And so we reduce the size of the -- we reduce the spatial scale of the study to try to be able to accommodate that. But then going the other direction as well, what does it look like to do any kind of a scientific study if you're not holding everything else constant? You know, now what you've got is a case study.

>> Exactly.

>> Which is describing what's there.

>> It's very difficult. I do think there are some things that we can do when we get to larger scales. So for example, one of the things is we could start to look for mechanisms rather than just the patterns. So you know, I find that some of the debate about what grazing system is the best and so forth, we sort of want to criticize small-scale studies which is fair enough. But we have the challenge you mentioned from large-scale studies, and it seems to me that sort of an integrative approach where we do the large-scale ranch-relevant studies, but we actually test the mechanisms with fairly controlled studies that correspond with those large studies. And it's really difficult to do that because of the, you know, the university tenure system and publish or perish and all those sorts of things. But I do think that's something to strive for.

>> Yeah, I would agree. I think that's a good transition into talking about pattern and process. But before I do that, I wanted to discuss just a bit what you lay out in the paper as the four foundational principles of rangeland management. Just to talk about that and then talk about how these ideas may be a little different or lead to a different kind of grazing management. You say in this paper that the utilitarian roots of range management that promoted protecting the soil and vegetation from disturbance and maintaining the output of products like forage led to four foundational principles of range management that focused on manipulating livestock grazing. Because that's the main -- it feels like that's the main tool we have. Those principles are one, to maintain a proper stocking rate; two, to achieve proper distribution of animals in space. Three, to achieve proper forage utilization in time. And four, to match the kind and class of animals to the desired plant community. I think that's a pretty accurate description of you know, what I would have laid out to a group of ranchers on grazing management. Even though I would say most of the mat least in the semi-arid west and much of Eastern Washington and Oregon and southern Idaho where I work is pretty dry. Landscapes don't really permit that kind of management. And so I sense that people are either frustrated with the inability to achieve those goals, meaning even distribution of animals and even utilization, or they give up and apply, you know, whatever stocking rate feels appropriate based on their own ideas of how much is right to leave at the end of the year, or whatever. You know, but you're saying that disturbances like fire, flood, drought, grazing, are important inputs that we need to maintain and that we need to have them in various degrees of intensity and spatial patterns across the landscape. How do you -- how do you mange for that?

>> That's a great question.

>> Or is it the wrong question?

>> Well, I'll tell you, I'll answer it this way. You know the old saying that when you're digging a hole, the first thing you do is put the shovel down. I feel like we've been managing to try and promote uniform utilization and a constant or an excellent range condition for each site and that's sort of been our goal everywhere, regardless of what our objective are, to be honest. In fact, I've worked with wildlife refuges where their goal, their objective was to manage for diversity of plants and animals, and I would ask them what is their management -- what is the target that they're hoping to achieve with their range sampling? And the answer is excellent range condition everywhere. And that's just not correct.

>> Right. And then what is meant by excellent?

>> Right.

>> You know, if you asked ten range scientists, we might get 27 different answers.

>> Exactly. Exactly.

>> Is that degree of similarity to some historic plant community? Or is that lots of tall grass everywhere? Yeah.

>> Exactly. And so, you know, in that example I tried to get them to recognize you actually need some areas that have some significant disturbance on them. And you should figure out how much of that landscape ought to be that way. And then other areas that maybe haven't been disturbed for a while. But I do think that the propers, as I call them, the four principles -- I still think they're largely relevant and important to think about. I just think that they become much less useful when you start to think about the world as highly spatial, highly variable in space and time. And so I -- you know, for example, if you just take the one that is clearly really important in the proper stocking rate, you know, you take a ranch in your part of the world that's 20,000 acres, what in the world would the proper stock -- the principle is probably correct that that's an important management decision. But how constant would it be from year to year? It would be highly variable. And I don't think our profession has really embraced that. And one of the reasons, to sort of get a little more philosophical -- I don't know if you've ever seen a paper by Hollings and Mefy, 1996 in Conservation Biology.

>> I don't think so.

>> It's a great paper. It's one of those that I don't know that there's any data in it. It's just one of those that makes you think a little bit. But they argue that there should be a golden rule of natural resource management, and the golden rule is that management should strive to retain critical types and ranges and natural variation to maintain resiliency. And so this is 1996. Well, I don't know that it's realistic to try and include the whole range of variability, but the recognition that that variability is important is critical. And in fact, they talked about it in terms of natural resource pathology, where there's this top-down control over what this piece of property ought to look like, that somebody somewhere else determines. And it may not be relevant from an ecological standpoint.

>> Or even possible.

>> Or even possible, for sure. And certainly it isn't possible every year. And so it seems to me that at least in North America and even on private land that that natural resource pathology of sort of the top-down seems to be as big of a problem as us understanding the natural systems and how variable they ought to be. So how do you get someone to decide that this is a well-managed ranch or not when they could obviously take -- if you promote heterogeneity, then they could go out and take a picture somewhere of a heavily disturbed area and paste it all over the internet and talk about how bad of a manager you were.

>> Right. Yeah, I have reservations in general about the wisdom of assuming that we know enough to manage toward some design or ecosystem. I like the idea of prescription grazing probably because I think the application of it right now tends to promote heterogeneity in a way that maybe we didn't before. But you know, in Extension and probably across a lot of great universities, you know, we live in a world of planning with the end in mind. And I think that idea relates to a general engineering paradigm that characterizes most of the 20th century in America where we figure we know enough to work toward whatever end goal we think is appropriate. But I don't know, it seems like that incorporates a dangerously large dose of hubris, of thinking that we can manipulate all the right variables, generate a specific set of landscape conditions for a particular species or a particular human need. You know, there's a lot that we know. But going back to your idea of ecological humility, I'm reluctant to adopt a stance that borders on claiming omniscience.

>> Oh yeah. Yeah. And not to mention that just the more we learn, the more we realize that you need a lot more variability in the world in order -- that that is more the norm. You know, I remember when I first started thinking about wildlife, and I was part of a group that had grant money to study how we can promote grassland birds because everyone was scared about grassland birds. And so I just dove into the data. And the first stop was, "Well, look. All these birds have different habitat requirements. How in the world are we going to manage for all of them?" And you know, you can't. You can't develop a prescription that says we're going to improve wildlife on rangelands. Not if that prescription is the way we've traditionally done prescriptions where it's you know, got a grass height target of, you know, six inches on average or something to that effect. It's just not very useful and it's a little bit arrogant in my opinion to sort of think that we can do that. And that's what's led to sort of the idea, well, if we can put these processes back and understand how they worked historically -- not that we're going to go back to 1491, because that's ridiculous. But if we could actually understand how they work, then we'll at least know when we want to manage for things like grassland birds what sort of conditions ought to occur and the processes that might be important for those.

>> So when you say patterned in process, what all is included in your definitions of those words?

>> Well, you know, it's funny. Some years ago there was a big symposium on ecological site descriptions and there was a push to make them process-based. And I was asked to talk in that symposium and I started looking up the definition of process. And I quickly found that there really wasn't a very good one out there. Similar to your question, it's just like, "What does this actually mean?" But I did find one that I liked, and I like it because it's really simple. It was -- and I don't remember where I came from. But it was all of the -ing words associated with ecosystems.

>> If you're going to steal something, forget where you got it.

>> Exactly, exactly. So nutrient cycling, you know, infiltrating, so sort of the action items of ecosystems. But the crazy thing about that is it does get quickly oversimplified because erosion, you know, is a process. I guess it would be eroding. Yeah. And you know, that's not necessarily something that we want a lot of. And we may not even want as much as would have occurred historically. And so it's kind of a dangerous assumption, because I do think when you start to say we're going to put pattern and process back like it was, all of a sudden you realize, "Ooh, we don't really want it like that." And the goods and services that we all want, because we're constrained by scale and we don't have as much land as we used to have, we have more people that we need to feed. We can't tolerate the Nebraska sand hills to be blowing away for a decade or something to that effect.

>> And if you're the guy that owns 50 acres, you don't want your place to be the blow.

>> Exactly. Exactly. And so I think the idea really behind pattern and processes, and a lot of this goes back to people I've known that are practical and managing the world. So for example, Bob Hamilton runs the Tall Grass Prairie Preserve in Oklahoma. And it gets overwhelming if you're trying to manage for diversity of everything, you know, if you have 8,000 graduate students monitoring their favorite species. And Bob is real quick to sort of say it's more like a run and shoot offense if you'd like a football analogy. But it's much less organized. And that you basically understand general principles and then you let the patterns and the processes work their way out. And not everyone could do what Bob does because he's got different constraints. But I feel like a little bit more of that acknowledgement that there's noise in these systems. And that as long as you're within this range of -- if there's some degree of normality, if you're in that area, then you know, it's probably okay to some degree.

>> Right. Any movement away from the drive toward the middle would be beneficial. As I'm thinking about this, I feel like you see that across the spectrum of agriculture. You know, from large extensive animal husbandry systems like rangeland grazing on 100,000 acres of desert to, you know, more say intensive agronomy like grow crop farming where you've got deep soil and 40 inches precipitation. But across that spectrum we apply fencing, weight control, brush control, flood control, herbicide, insecticide, fungicide to try to manage toward some really specific idea across the whole thing. And you're saying any movement away from that is going to likely produce some beneficial heterogeneity.

>> Yeah. I think that's right. I think that's a good way to describe it actually. And I am not suggesting that all those things that have tended to be used to push us to the middle can't be used. In fact, some of them can be used differently to even promote heterogeneity. But the way they've been traditionally used, it's sort of under this uniformity paradigm.

>> Thank you for listening to the Art of Range podcast. You can subscribe to and review the show through iTunes or your favorite podcasting app so you never miss an episode. Just search for Art of Range. If you have questions or comments for us to address in a future episode, send an email to For articles and links to resources mentioned in the podcast, please see the show notes at Listener feedback is important to the success of our mission, empowering rangeland managers. Please take a moment to fill out a brief survey at This podcast is produced by Connors Communications in the College of Agricultural, Human and Natural Resource Sciences at Washington State University. The project is supported by the University of Arizona and funded by the Western Center for Risk Management Education through the USDA, National Institute of Food and Agriculture.

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