Capturing 40 years of climate change for an endangered Montana prairie

Though cooler and wetter springs drive an increase in grass production compared to 1978 levels, hotter summers mean all that green goes brown faster–and plants have a harder time reinitiating production in the fall


Research News


Over 40 years of monitoring, an endangered bunchgrass prairie became hotter, drier and more susceptible to fire annually–but dramatic seasonal changes (not annual climate trends) seem to be driving the biggest changes in plant production, composition, and summer senescence. Gary Belovsky and Jennifer Slade of The University of Notre Dame, Indiana, present these findings in the open-access journal PLOS ONE on December 23.

Intermountain bunchgrass prairie is one of North America’s most endangered ecosystems, now covering less than 1 percent of the area it once did. Over the past century, bunchgrass prairies have become warmer and drier, and human-driven climate change is expected to continue that trend, with potential impacts on bunchgrass ecosystems. However, bunchgrass is often overlooked in studies of grasslands.

To better understand the effects of climate change on bunchgrass prairies, Belovsky and Slade studied the National Bison Range, a bunchgrass prairie in Montana, for 40 years. They made repeated observations of plant growth and production, abundances of different plant species, and availability of nitrogen (an important nutrient for plants), generating a comprehensive timeline of ecosystem changes.

Over the course of the study, annual temperatures rose and precipitation declined in the prairie, making it more susceptible to fire. Surprisingly, the researchers found that annual aboveground primary production–the amount of plant material produced every year–rose by 110 percent, associated with increased precipitation and cooler temperatures during the important growth period of late May through June. However, this was associated with a change in plant composition, with a 108 percent increase in invasive species, more drought-tolerant species being favored overall, and declines in dicot non-grass plants (decreasing by 65 percent) over the 40-year study period.

The researchers also found that other ecosystem changes followed seasonal climate trends, instead of annual trends. For instance, summer temperatures were higher than might be expected from annual trends, boosting summer senescence– the yearly “browning” of green plant material.

These findings highlight the importance of considering local and seasonal changes when forecasting the effects of climate change on a given ecosystem. The authors report that intermountain bunchgrass prairie could be morphing into a different type of grassland that may be previously unknown.

Dr. Belovsky adds: “Forecasting climate change effects on plant production based on expected average annual increased temperature and decreased precipitation may not be appropriate, because seasonal climate changes may be more important and may not follow average annual expectations.”


Citation: Belovsky GE, Slade JB (2020) Climate change and primary production: Forty years in a bunchgrass prairie. PLoS ONE 15(12): e0243496.

Funding: Funding to 1st author GEB: National Science Foundation: NSF – NSF DEB-78-02069, NSF BSR-83-07352, NSF DEB-93-17984, NSF DEB-97-07564, NSF DEB-04-15390, NSF DEB-09-18306, NSF DEB-1456511 National Geographic Society Grant FY79 –; University of Michigan Rackham Graduate School –; University of Michigan Vice-President of Research Grant –; USDA/GHIPM (1989-1994) – (GHIPM program ended in 1994); Utah State University Agricultural Experiment Station (1992-1996) –; USDA/ARS and USDA-CSREES/NRICGP (00-35101-9267) – The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing Interests: The authors have declared that no competing interests exist.

In your coverage please use this URL to provide access to the freely available article in PLOS ONE:

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December 26, 2020 10:22 pm

“and human-driven climate change”

ummm….. where do they prove the climate change is human-driven ?

Just a “throw-away ” nonsense statement.

Reply to  fred250
December 26, 2020 11:02 pm

“and human-driven climate change” must be true because I read it somewhere… Actually we read it and hear it everywhere like it’s the prayer mantra of a global cult or the mumbling of herds of zoombies as they ravage the land, putting up solar panels and wind turbines wherever they go.

Reply to  fred250
December 27, 2020 12:15 am

Where does anyone …. ever ?? A failed 19th Century conjecture, like the canals on Mars.

Reply to  fred250
December 27, 2020 9:12 am

The climate of Earth is constantly changing! That IS a fact. It has been changing since the Earth was formed. It will CONTINUE to change, until the Sun and the Earth both explode and disappear, in another 5 billion years or so. During the entire existence of the Earth MAN has only been present, in one form or another, for at best, a few million years. Therefore, man has NOT had any impact on the ‘climate’ other than some minor fluctuations. But, now, the climate ‘scientists’ want us to believe that, because of US, the Earth is going to die, in a few short years! If we were able, somehow, to consume ALL of the fossil fuels, AND coal, at one time, what difference would it make, since all of the carbon CAME from the Earths environment in the first place? EVERY single element on or in the Earth follows a cycle, including carbon. At some point in the distant future even carbon (coal) will be returned to the surface to begin another cycle. It’s the same for water, and all other elements. We may have sped up the ‘cycle’ for coal and hydrocarbons by using some of them, but that, too, is a natural process. The best thing humans can do is simply learn to co-exist with the ‘climate’, as we have ALWAYS done in the past! Everyone complains about the weather (climate) but no one can do anything about it.

December 26, 2020 10:24 pm

That all sounds reasonably scientific but they can’t leave out the speculation as to what the future is going to bring which isn’t.

December 26, 2020 10:30 pm


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Does anyone have access to un-adjusted non-urban temperature data ?

Reply to  fred250
December 26, 2020 11:12 pm

Thanks! Data says the prairie is actually wetter over the past 40 yrs (and has periodic dry spells every ~25-30 years). Climate Scientist (or should I say Scientologist) ignores data and repeats what political scientists have told him. Science is dead.

Reply to  fred250
December 27, 2020 8:17 am

Um, y’all do know that “intermountain” bunchgrass prairie is not in NorthEASTERN Montana, right? All of Eastern Montana is in the Great Plains. Western Montana is where the mountains roam and shelter the intermountain area between them.

Perhaps there was no more relevant chart available?

Reply to  K. Leonard
December 27, 2020 10:53 am

Perhaps YOU could spend some time finding the actual data you want. !!

Reply to  fred250
December 28, 2020 5:10 am

Unadjusted data is no magic bullet. I have the sense that some skeptics, realizing how dubious many adjustment procedures are, have made the usual cognitive consistency pirouette and now regard unadjusted as the ‘true coin of the realm’. It isn’t; it has all the problems (TOB changes, location changes, instrument changes …) that the AGW proponents have claimed (and documented).

(The problem with adjustments on the other hand is that they can quickly descend into fantasy. So this strategy is no magic bullet either. There’s really no way out of the box.)

December 26, 2020 10:47 pm

The study covers the Bison Range which is 9,000ha, or about 35square miles. It is surrounded by farms…🤔
Montana has 147,040 square miles…🤣🤣🤣
and people get paid to do this stuff????

Reply to  Brad
December 26, 2020 11:28 pm

Well, the fact that those farms are not even alluded to in this “study” must surely mean they are not those horrible, unsustainable family affairs. And we all know how the wonderful, sustainable factory farms drenched in Monsanto’s dreck never cause any detrimental environmental issues, ever. Also, I see nothing about underground water levels, grazing use or animal densities…
But what do I know, silly me, thinking 9000 hectares is about the size of one large farm, unsuitably miniscule for the purposes of studying the Climate, which I, in my ignorance, thought was a thing that happens on global scale.
Someone ought to recondition me!

Reply to  Brad
December 27, 2020 5:01 am

There is nothing natural about a prairie. It is man made so Bisons can live there in the millions

alex parkhurst
Reply to  Robertvd
December 27, 2020 9:42 am

I live near here and have been on the bison range many times. It is between Kalispell and Missoula in NW Montana. It is or has been turned over to the Flathead Indian Res where there are no Flathead Indians. Topic for another day.

This is a manufactured “ecosystem” in my opinion. Case in point:

There are no antelope in NW Montana. They are in the rest of the state all over the place but not here with one exception. Guess what, there are antelope on the bison range. They were introduced and you can’t hunt them. So, I would not compare this grassland to any other in NW Montana for that reason.

Reply to  Brad
December 27, 2020 2:37 pm

6 X 6 miles is a typical township on the high plains.

Steve Case
December 26, 2020 11:16 pm

Dr. Belovsky adds: “Forecasting climate change effects on plant production based on expected average annual increased temperature and decreased precipitation may not be appropriate, because seasonal climate changes may be more important and may not follow average annual expectations.”

And Decreased Precipition?
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Peta of Newark
December 26, 2020 11:59 pm

I’ve said it all before. sigh

And they’ve entirely wasted their 40 years. If they wanted to record Climate Change, they’d have planted a few CO2 flux meters out on the grassland.
Ooooh – does any wizened old cynic think they maybe did? Now then…

Otherwise what we have here is a lovely exposition of just how varied and wonderful Nature is and how it runs rings around folks who think they are studying Natural Philosophy
yeah right.
Magical Thinking yes, actual thinking not-so-much

i.e. Hatch a theory, any theory, then if you look hard enough you will find evidence to support it

Unless you took out a CO2 meter and said device drove a Coach & Horses through your Beautiful Theory.
Or a device that recorded how much NPK (fertiliser, plus sulphur not least) was falling out of the sky
Or any number of things, not least a Blinker Removal Device to use upon yourself.

A small herd of bovines would have sufficed, might have saved them the effort of producing this BS

That silly ol’ Ma Nature has a gorgeous sense of humour ain’t she

Old England
December 27, 2020 12:06 am

Despite 40 years work being admirable it is a tiny snapshot in time that takes no account of what has preceded it.

What immediately struck me was that without knowledge of the composition of grasses and plants going back into the early 19th century or before there was little value in this study’s findings that grassland plant composition has changed.
For example :

Is it returning to an earlier / previous grass/plant composition ? What was it in the 1920s and 30s or during the 1850s or 1890s

What effect have changes in grazing patterns (bison herds etc) over 200 years had?:

What effect have local or adjacent agricultural practices brought ?
etc etc

Reply to  Old England
December 27, 2020 5:26 am

The 1930s are close to living memory and are well documented anyway. Now that was climate change.


Burl Henry
Reply to  commieBob
December 27, 2020 11:21 am

Commie Bob:

“Now that was Climate Change”

Yes, and we inadvertently caused it.

Reply to  Burl Henry
December 27, 2020 1:00 pm

I don’t know if I read about it on WUWT or somewhere else but there was an article around two years ago about a study of several thousand years worth of Dakota lake sediments revealing things about the constantly changing local climate which they seemed to project to the Midwest plains area in general.

The conclusion was that extensive droughts were a repeating phenomena over that time period and that the Dust Bowl years were a rather small example of those droughts. Probably the dust part was human caused as there is scant evidence that the native ground cover was ever removed before, but the drought itself was likely just one of those frequently passing things.

Reply to  Old England
December 27, 2020 7:19 am

Exactly. From Britannica:
By 1870 the bison population on the Great Plains had been divided into two parts, lying north and south, respectively, of the Union Pacific railway line. The southern herd was completely destroyed by 1875 and the northern one by 1885. By 1889 there were fewer than 1,000 bison left alive in all of North America.

40 years ago was 1980, a blink, and nowhere near far enough back to represent “the prairie”. They need to establish a baseline from around 1850 or so, when millions of bison defined the prairie flora and fauna… By 1980 it truly was a man-made environment, though not due to climate.

Reply to  Old England
December 27, 2020 7:20 am

Brings to mind the demise of the Rocky Mountain Locust.

December 27, 2020 12:12 am

Surprisingly, the researchers found that annual aboveground primary production–the amount of plant material produced every year–rose by 110 percent, associated with increased precipitation and cooler temperatures during the important growth period of late May through June.”

Come on, friends don’t let friends say such stupid stuff. Any friends (do they have any?) on here who could tap these clowns on the shoulder and tell them there’s another reason.

December 27, 2020 1:21 am

40 Summers together on the North Montana Bison Prairie, growing old together. Ah how romanatic ;

Reply to  Nick
December 27, 2020 2:43 am

And of course in the USA, the 1970s-1990s was the COLDEST period since about 1900


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December 27, 2020 4:57 am

The prairie is a man-made environment that can only exist with these grasses if it is burned down or eaten or trampled by millions of hooves.There is nothing natural about a prairie.

Reply to  Robertvd
December 27, 2020 11:47 am

Wouldn’t it be more correct to say that the prairie was bison-made? And wouldn’t that be ‘natural’? Or did the natives actively manage the prairie and protect the bison like farmers would? I know the current little prairie section mentioned in the post is just a postage-stamp compared to the former extent of the range, really just a hobby farm for the scientists, but the original prairie was a natural feature, surely?

Ewin Barnett
December 27, 2020 5:08 am

I could cite any number of massive changes in the climate that had no connection with human activity. One example would be the very reason we have the quaint tourist attractions of the abandoned cliff dwellings in the American southwest. Earlier, a massive lake evaporated away:

Not all change is the fault of humans. To say otherwise is either being careless or being ideological, neither of which is consistent with scientific discipline.

Jim Gorman
December 27, 2020 5:22 am

As I have been saying all along about Global Average Temperature. It makes little sense to start with, has real problems with uncertainty, and isn’t relevant to local and regional effects.

“… specific seasonal, not annual, climate change trends may be more important [8,13,2325] at local spatial scales [1114], and questions U.S. grassland projections made at large spatial scales”

“This large phenological change was not related to increasing temperature as often projected [7,75], but related to increasing grass relative abundance and the increasing ratio of late-May–June precipitation to temperature. 

Trying to Play Nice
December 27, 2020 5:52 am

“These findings highlight the importance of considering local and seasonal changes when forecasting the effects of climate change on a given ecosystem. The authors report that intermountain bunchgrass prairie could be morphing into a different type of grassland that may be previously unknown.”

Those of us who follow real science would probably replace the word “morphing” with the word “evolving”. They should read up on a guy named Darwin who came up with the idea of natural selection. It probably would explain why their little prairie is not exactly the same every year.

Tom Abbott
December 27, 2020 6:59 am

From the article: “Over the past century, bunchgrass prairies have become warmer and drier,”

Actually, the bunchgrass prairies have become warmer and then cooler and then warmer again, and may be starting to get cooler again now.

I imagine had these scientists done their study during the period from 1910 to 1940, they would have gotten the very same results because the temperatures increased from 1910 to 1940, at the same rate as the temperatures have increased over the last 40 years.

Then the temperatures cooled for 40 years, after 1940. I wonder what a study of that 40-year period would show?

Their mistake is assuming there has been nothing but warming over the last century.

The Earth’s climate operates in a cyclical fashion, where the climate warms for a few decades and then cools for a few decades and then warms again for a few decades and on and on.

Here is an example of the real temperature profile of the Earth:

US surface temperature chart (Hansen 1999):

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As you can see, it was just as cold around 1910 as it was around 1980, and the temperatures rose in both instances until they reached the high point of 1934, then they cooled to 1980, and then they warmed again up to 1998, which was 0.5C cooler than 1934. The warming from 1910 to 1940 is equal to the warming from 1980 to the present day.

All regional surface temperature charts have a similar profile to the US chart. They all show it was just as warm in the Early Twentieth Century as it is today. They all show that we are *not* experiencing unprecedented warmth today, which means that CO2 is a minor player in the Earth’s climate. So minor, that we don’t need to worry about it.

If we go by the actual temperatures recorded by human beings, then we have nothing to worry about from CO2.

Only the bastardized, computer-generated Hockey Stick charts show steady warming over the last century.

No unmodified regional surface temperature chart resembles the “hotter and hotter” temperature profile of the Hockey Stick charts. The Hockey Stick charts are just Big Lies aimed at promoting a political agenda.

Reply to  Tom Abbott
December 27, 2020 12:58 pm

For those who missed what the study authors took into account of time spans & assume they only considered 40 years consider this bit from their report. The study sector “… has become warmer and drier based on annual averages over the past 109 years … [O]ne can observe 4-6 and 10-15 year cycles in precipitation and temperature … given cyclic oceanic drivers … [which] can not account for the 40 year … change[s] … only modify them ….”

To me there were quite a few interesting observations in this study. I take it as par for the course that publishing agronomic research obligingly pays lip service to climate change & don’t let that get in the way of considering presented data.

December 27, 2020 7:46 am

Static world view again predominates. The condition of the bunchgrass prairie over the last 500 years was not stable. It was just a moment on a continuum of biological change that began 500 million years ago.

December 27, 2020 7:56 am

How much did the loss after 1850 of more than 30 Million Bison have on the prairie ecosystem. By 1889 The population was estimated to be down to 550 animals.

alex parkhurst
Reply to  DipChip
December 31, 2020 7:50 pm

A man from our county saved the American Bison:

Then again if you have been to Poland or the Bavarian Forest National Park in Germany
you can see “Wisent” – they look just like our Bison so we could have taken some from Europe and started over here.

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Steven Curtis Lohr
December 27, 2020 8:47 am

The worthlessness of this study, or whatever it is, has been properly stated. But, the actual purpose of this piece of “work” has nothing to do with science. It is a PR effort while jacking around the ranches and locals who are trying to keep their way of life and economic viability in Montana. It is hard to pin down in a few sentences but there is a growing force of hucksters who finance a mash-up of so called field work for the purpose of promoting popularized and politically motivated ideas like: global warming, rewilding, non-GMO, anti-frac, or a grand “prairie reserve”, etc., etc. It enables ignorant people to spout nonsense in the presence of others of equal or greater ignorance for the sake of signalizing their personal value. Much like clothing is used as a signal, now it’s jackass ideas that people repeat for their own self aggrandizement by conjuring “cyantiphic studdies”. And, our greater misfortune, is the fact that there are people who will happily give them money to do this stuff.

Mike Dubrasich
Reply to  Steven Curtis Lohr
December 27, 2020 9:39 am


Reply to  Steven Curtis Lohr
December 27, 2020 10:26 am

Excellent analysis! There are similar people in the energy conservation industry who get paid $100,000+ to write papers that can be debunked based on simple critical thinking inside of 30 minutes. However, try telling the truth to someone whose “existence” is justified by such drivel… it could easily get you killed.

December 27, 2020 9:19 am

I remember an article on WUWT a number of years ago about investigating the animal bones found in middens of Indian settlements somewhere out there in the west that found the animals in their diet varied from forest (deer, rabbit etc) to prairie (bison, prairie dog etc) and back again over a period of about 900 years due to changes in the rain shadow of the Rockies. Dont remember the exact dates of remains studied, but think it was a few thousand years ago. That study was interesting, but I am totally unimpressed by a 40 year study with inconclusive virtue-signaling results.

December 27, 2020 10:11 am

First amendment at play to coddle more funding…and that’s fine – unfortunately zero ‘letters to the editor’ from anyone on this forum will be answered…and that’s not fine

Mark Thomas
December 27, 2020 10:49 am

After reading the paper, let me paraphrase the conclusions. The climate in the study area has warmed over the last 100 years due to Anthropogenic induced changes but plant growth unexpectedly increased which doesn’t fit our agenda so we think the ecosystem is morphing into something new and unknown (and therefore bad) and we will get back to you when we figure out how to turn good news  (higher plant growth) into bad news.
Note: I live ~30 miles north of the NBR.

John F Hultquist
December 27, 2020 11:13 am

” … <em>with a 108 percent increase in invasive species </em>”

Carried there by climate change.

December 27, 2020 11:19 am

Much of the National Bison Range was once at the bottom of Lake Missoula, while higher elevations were under glacial ice. At some point, wouldn’t bunchgrass have been an invasive species?

Tim Gorman
December 27, 2020 11:44 am

Overall the historic description of Montana is a semi-arid desert. What do these scientists think happens in a semi-arid desert climate? Forty years simply isn’t a long enough time period to understand what is happening.

I also wonder just what these scientists think hay is? It is dried grass! Cattle eat it all the time! A browned prairie is nothing more than HAY!

So what’s the big deal?

Pat from kerbob
December 27, 2020 12:05 pm

Posted before but

Montana is just south of where I grew up in the Palliser Triangle, so named for captain John Palliser who travelled through the area in the 1800s on behalf of the Canadian government, and found it to be a desert wasteland unsuitable for settlement

Then when the CPR came through a decade later they figured he must have been on crack as it was green and lush

In my life time the area was green and lush in the mid-70s, in 1990s it was desert sand dunes so hot it was difficult to walk in them in boots.

A couple years ago I took my family to see the dunes and all that is exposed is leading face, otherwise grasslands again

Continuous change
An amazing thing

Elle W
December 27, 2020 1:33 pm

Here’s an idea. Montana is the same size as Germany. Let’s put 82 million more people in Montana , and then have them all virtue signal how green and “woke” they are with their prairie grasses.

Reply to  Elle W
December 27, 2020 9:23 pm

Germany is a little smaller than Montana, so we can send more than 82 million people. Lets say: 19.7 (NYC + Buffalo NY) + 5.8 (Atlanta) + 3.5 (Detroit) + 8.8 (Chicago) + 5.7 ( Philadelphia) + 2.2 (Portland) + 3.4 (Seattle) + .95 (Milwaukee County WI) + .8 ( Minneapolis/St Paul) + 12.5 (LA) + 2.2 (San Francisco) + 4.5 (Phoenix) + 1.6 (Fairfax and Prince William counties VA) + 4.3 (Boston) + 2.8 (Denver) + 2.7 (Miami/Dade County FL) + .9 (Las Vegas + N Las Vegas NV) + .9 Albuquerque + .5 (Raleigh NC) + the populations of some other key Democrat controlled cities and we would put the leftist voters together in one state and flip 11 States and secure the others for years for conservative voting. The US would not elect a Democrat President for decades. Of course we would lose one sort of conservative state. They really couldn’t complain, they have been electing Democrat John Tester since 2006. I figure we could set up refugee camps for those driven out, providing all refugees with a substantial financial settlement for their trouble if they can, through a through background check and sociological testing, verify their conservative bonafides. If we added Montreal and Toronto to the input we could also save Canada, and thus all of North America for years to come.

Of course we would need to put HUGH wall around Montana to keep the trouble that leftists cause in Montana.

Getting rid of the northern Virginia counties will get rid of many unneeded deep state operators, an added benefit.

December 27, 2020 3:42 pm

Take several millions of bison and antelope off of a grassy plain, and decades later categorize the local changes to flora and fauna as climate change. And then call that science… fiction.

Tom in Florida
December 28, 2020 10:28 am

“Dr. Belovsky adds: “Forecasting climate change effects on plant production based on expected average annual increased temperature and decreased precipitation may not be appropriate, because seasonal climate changes may be more important and may not follow average annual expectations.””

We all know that averages are just that, averages. They give no detail to what is occurring at any given point in time.
And he gets paid to “discover” this?

December 29, 2020 6:02 am

I can write fiction, too.

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