The Lesser Prairie Chicken says rangelands aren’t as healthy as we thought
Submitted by joel brown on Mon, 03/31/2014 - 14:55
The U.S. Fish and Wildlife Service just proposed to list as ‘threatened’ the Lesser Prairie Chicken throughout much of the high plains region based on a precipitous decline over the past 10-15 years. This shouldn’t have happened. Rangeland management has been based on the idea that if we manage a particular piece of land, or a ranch, or a landscape correctly, then we should expect more stable production of livestock products, water yield, and wildlife. Proper rangeland management produces resilience--the ability to withstand the vagaries of climate and still yield a fairly consistent income. We have been pretty good at this; rangeland management has improved vegetation cover on rangelands throughout most of the U.S., certainly not to the point that we would like, but progress nonetheless. However, even as those indicators of ‘health’ have continued to improve, we have seen new problems emerge.
When we look at the indicators of rangeland health in the historic range of the prairie chicken (plant species composition, amount of rangeland acreage, soil health, etc.) we generally see stable to slightly upward trends for the past 20-30 years. So, why is a species dependent on rangeland in decline while our measures of rangeland health indicate improvements? Well, there is always the possibility that our measurements, of either bird numbers or rangeland health, are wrong. Or, dramatic changes in the amounts of rangeland that occurred in the past are just now having an effect on population numbers.
The other, very strong possibility is that something else is going on and is responsible for the instability in lesser prairie chicken numbers. In the FWS press release on the listing proposal, they listed road building for energy exploration, wind turbine tower construction and oil and gas drilling rigs, in addition to habitat loss to agriculture as the reasons for population decline. Agencies and land owners have been proactive in managing to improve habitat, including preserving open land and converting marginal cropland to perennial grasses. But, a critical question would have to be: can large scale land management efforts (like grassland restoration or rangeland improvement) overwhelm the negative effects of widely distributed small-scale disturbances (like roads, power lines and wind towers)? Or in the context of one of Brandon’s earlier posts: are the positive feedbacks (instability) associated with energy development outweighing the negative feedbacks (stability) associated with conservation via land use and management?
While we can use tools such as soil survey, ecological sites, remote sensing, GIS, population models and many yet to be developed, a very difficult problem remains; how do we examine and communicate to people about how entire land mosaics are changing, what we can do about it, and most important, how do we logically make those decisions given that they involve such large expanses of land and so many competing interests? We’ve done a pretty good job of developing tools that can tell us about the quality of a small, isolated piece of land, but we’re not particularly good about the landscape and regional context that determine how prairie chicken populations function within the ecosystem.
We have some theory to guide our thinking. In 1985, the book The Ecology of Natural Disturbance and Patch Dynamics by Steward Pickett and Peter White illustrated how fairly dramatic changes in comparatively small patches could affect stability in larger scale processes. The idea that stability, and sustainability, at larger scales depended on change in the qualities and arrangement of smaller subunits, is really interesting as a theory, but poses some challenges for managers and policymakers. It means that in spite of our best efforts to improve the health one piece of ground, or to incentivize improvements across a broad land area, land uses in certain areas--that are outside of our immediate control--may thwart our goals. It’s a well understood theoretical problem in landscape ecology, but that doesn’t mean we are any closer to using the ideas in designing land management strategies. Maybe the prairie chicken can tell us how.
- joel brown's blog
- Log in to post comments
I agree with most of what you have to say here Joel, but one thing that I always
come back to, is the fact that we spend so much time focusing on single species.
How can we think broader in our perspective of landscape ecology if we continue
to manage wildlife that use those landscapes one species at a time? I think it's difficult to broaden people's perspectives when we continue to take them down that road of thinking about the impacts to only one species. I truly think the focus needs to be on ALL of the species that are lost across that landscape due to changes and disturbance pressures and their connectivity to the ecosystems they depend on, so people understand it's not just one species we lose when habitat is fragmented and lost, but it's a domino effect of loss in the diversity of species that utilize that same land. The enormity of losing habitat for many species over just one specific species really should be emphasized as much as possible...even if that one is the one species deemed to be cared about the most. Just my two cents...:)
“Maybe the prairie chicken might tell us how” to better incorporate patch dynamic and landscape disturbance theory into our land management strategies? Perhaps we should learn its language before bringing PC into the management team or at least strive to listen more closely. It seems to me that rangeland health as assessed by the current protocol only implies potential prairie chicken habitat quality since it was never designed to specifically address habitat quality with any great specificity or population requirements in any way.
Assuming that rangeland health and prairie chicken population stability have a 1:1 relationship is sort of like connecting a grounded device to an ungrounded outlet then hoping for the best as thunderstorms approach. We might get shocked but we shouldn’t be surprised when new evidence once again confirms once again that the device (rangeland health) wasn’t designed to match the power source (population stability requirements).
Don’t get me wrong, I don’t find anything inherently problematic with the rangeland health protocol and in fact I believe it to be a very powerful tool –the results simply require consideration in an appropriate context. In relation to informing the land management strategy, we have to have a better idea of which scales are critical and which elements are limiting factors at each of those scales.
prairie chicken mechanics
Both of these comments are really good examples of the value/danger of a systematic evaluation of land condition. In the first instance "why do we have to focus on a single species?" is a good question, but it really illustrates why we need broad, rather than narrow interpretations. We have to focus on a single species because we are so close to the edge on many of these species/services that being just a little bit wrong puts us in danger. It would be great if we had a lot of resilience, and some room for error, in our rangeland systems, but the reality is that we are so close to a threshold of a dramatic change in ecosystem services that what might have been a minor mistake 30 years ago is today a serious threat. As those margins for error become less and less, the risk of a bad decision goes up. Jon Gustafson (Toaster-fork?) is right that a good tool for one interpretation may not be a good tool for another situation. In this case, a tool that lacks precision in accounting for species dynamics (but is pretty good at habitat extent) can be useful if we have some margin for error (in both time and space), but as we get closer to the threshold, we really need a too with much more focus. As any good mechanic will tell you, "the right tool for the job". At least that's what they tell me when I pay the bill at the garage.
managing endangered species
Looks like there is an intriguing new article in press at Rangeland Ecology and Management. Chad Boyd and his colleagues at ARS in Burns OR have a paper examing the challenges in implementing a regulatory, species specific approach as contrasted with more of an ecosystem management approach using tools like state-and-transition models. Chad and his coworkers always seem to come up with innovative and creative proposals to difficult problems. I suggest having a look.