Monday, May 20, 2024
HomeThe Thinking GrazierAdapting to a Changing Climate

Adapting to a Changing Climate

Editor’s Note: I just got back from 5 days in the largest 2C hot spot in the Lower 48. Grand Junction, Colorado is in the middle of a 30,000 square mile region that has warmed as much as 3.5° C (5° F) above pre-industrial levels. The result, in addition to hotter summers and warmer winters, is a reduction in snowpack, and less water for the peach orchards, vineyards, and ranches of the Grand Valley. The area is currently in a twenty year drought.


Two degrees C is thought to be the upper limit of warming before we experience significant sea-level rise and impacts on food production and water supplies.


This region is just one of a number of 2C hot spots in the United States where we are getting a preview of what could happen should global warming exceed 2° C. In all of them, farmers and ranchers are faced with the challenge of adapting to weather extremes and climate change.

On Pasture author John Marble ranches in Oregon near one of these growing hot spots, so this month, “The Thinking Grazier,” looks at what John is experiencing and how he is adjusting his grazing management and his operation in both the short and long-term. I hope seeing his example will help you think about how you can work through similar problems, whether you face them now, or in the future.

Thinking Like a Plant

After a relatively normal winter season (which around here means lots of cool, gray, soggy days) our spring growth began as expected. A bit of tender growth in February, increasing excitement and greening up in March and a promising start to the grazing season on April first. And then, of course, came the drought.

Our prime grass-growing months are March, April, May, and a bit of June. The days are warm and wet, with a weather pattern passing through every week or two. During this time of year, I push hard to achieve a 30 to 40-day rotation, trying to keep the grass from thinking about reproduction. Typically, we begin to see our weather and soils drying out enough that growth really slows down during the first half of June. After that, we are basically grazing residual growth, as new growth falls to nearly zero for the summer.

This year, a funny thing happened. Around the time when the grass should really be screaming along, it simply stopped raining. This meant that the only moisture available to the grass plants was whatever had already accumulated in the soil. Within a few weeks, this moisture was exhausted, and some plants (annuals in particular) began acting like it was already summer: hardening up, growing more stem and less leaf, trying to set seed.

Woody Lane, PhD is a livestock nutritionist and forage specialist who coordinates and advises several grazing groups in Oregon.

“But this is April, not June! If this grass goes to seed, we’ll be done grazing in no time,” I said to myself. I found myself searching for a way to put a positive spin on things. Looking for some sort of optimistic support, I called my grazing guru and friend Woody. In my most hopeful voice, I asked a question:

“Hey Woody, if we’re in a severe enough drought, is it possible that the plants will decide to just keep growing but forget about reproduction? As in, just stay in the vegetative state and give up on setting seed? Like, just preserve themselves for next year?”

There was a short pause on the line, and I could almost see Woody place his hand on his brow, his head shaking from side to side.

“Absolutely not. The annuals are already doing their thing, and the perennials will access whatever moisture they have stored in their roots, leaves and stems and make a mad dash to go to seed, and soon. Nothing will stop them. After all, plants have only one fundamental mission, and that is to reproduce.”

Of course, in my heart of hearts, I already knew this. I was simply hoping for an easy way out. The real questions now were…

If the drought continues, what’s going to happen to my grass?
What will my grass inventory look like?
How can I best use the grass supply that I will have for the rest of the summer?

What the Plants Tell Me in 2021

I can start to answer my questions by comparing typical plant growth rate/speed to what I see happening during the 2021 drought.

Here’s a normal year growth speed curve:

The repeated sharp declines in growth rate during a typical year indicate what happens when a grazing event occurs. Each sharp decline (grazing event) is followed by a few days of very slow growth, then a period of  increasing growth rate as the new solar panels come into play. As we begin to run out of soil moisture in mid-June, plant growth slows to a crawl, and we are left to graze only dormant residual grass for the remainder of the summer.


Here’s the 2021 drought growth speed curve:

I got one normal rotation followed by what looks like recovery. But, 100% of the regrowth was stem and seed – no leaf growth. The majority of the grass for May, June, July and August is mature, poor quality grass. It can’t put good gains on cattle, but is what people will buy when they don’t have any grass at all. Knowing this, I de-stocked by 60-70% after the first grazing rotation.

What I Know About How Grass Grows

I developed these curves based on an understanding of how plants grow in general and what they do in our area specifically.

Plants initiate growth in the spring due to several factors: length of daylight, intensity of light, increasing ambient temperature, increasing soil temperature, moisture, humidity, nutrition and probably a few other things. Later in the growing season, plants begin moving from worrying about growth to worrying about reproduction. Thoughtful graziers recognize this and prevent reproduction through occasional defoliation. As long as adequate soil moisture remains, plants simply revert to re-growing the lost foliage.

Seed production is a normal phase of plant growth, but the onset of seed production can be highly influenced by the stress of drought (lower than normal soil moisture). Speaking anthropomorphically, it’s as if the plants wake up one day and say “Hey! We’re almost out of water! We better get to making some seed!” and the race is on. Desperate to reproduce, plants gather nutrients and water from their roots, stems and leaves and produce as much seed as they can. This change seems to happen overnight, and as a sward changes from vegetative to reproductive, the quality of pastures goes from good to…not so good.

Evapotranspiration is a combination of two ways that water cycles back into the atmosphere: evaporation from the soil, and transpiration from plant leaves. USGS diagram.

Aside from simple drought (a lack of precipitation), the amount of moisture in the soil is highly influenced by evapotranspiration. And this loss of water from the soil is highly influenced by temperature. In short, hot days drive more moisture from the soil, which encourages plants to set seed even more rapidly.

In our case, 2021 brought both drought conditions and record-breaking heat waves. It should be no surprise then that on a hot day in early May, our grass community went completely out of control. Total capitulation. Every plant went to seed, right in the middle of our traditional grass-growing season. I had already activated my drought plan, but now I had a bunch of un-desirable, overly mature, ugly grass to deal with. And that kind of grass requires some aggressive management.

My short-term response

Bring in adult custom cows and harvest that rank feed.

I had sold off most of my personal cow herd. The custom yearlings were set to leave in only a few weeks. The remains of my personal herd had been shifted to a mountain ranch nearby and were not available. And here I sat with 100 paddocks of ugly grass.

Question: What sort of livestock could best utilize this sort of feed?

Answer: Dry Cows.

OK, so go buy a hundred dry cows, or have someone send you 100 dry cows.

These are hard to find on short notice. But, while I was pondering this problem, the phone rang. It was a neighbor telling me a sad story about the condition of her pastures due to drought. She was trying to make hay on her meadows but had no place to graze her cows for the summer, as all her pastures were already grazed to the dirt. When I told her I had some tough, ugly grass where she could run her cattle, she was ecstatic. I told her my plan: I would graze her cattle hard enough that they wouldn’t lose weight. This was the best I could do. She was still ecstatic.

One more phone call brought an immediate “YES!” from another neighbor. He’s a business guy, who recognizes that paying a dollar per day for grazing is a lot better than paying three dollars per day for hay.

Suddenly, I was all filled up with cows, cows that could utilize my rough grass.

My long-term response

Move toward a grazing enterprise that matches our climate. Here’s my thinking behind that.

As Goes the Climate, So Go the Plants

Decades ago, I remember telling graziers that our biggest advantage here in western Oregon was that our weather patterns were so predictable: a warm wet spring followed by a warm dry summer. Some fall rains for late-season grazing. A long cool winter. Planning the grazing season was simple, as I knew exactly what was going to happen. The forage curve matched fairly well with the nutritional needs of a cow-calf operation.

Evidently, that is no longer so. Our climate appears to be shifting away from Marine and more toward Mediterranean. Our summers are growing steadily hotter and we are threatened with drought every spring, it seems. Our forage curve shows a shorter, more extreme pattern of growth, a pattern enforced by a lack of soil moisture. This sort of pattern looks more and more like the life plan of annual plants rather than that of perennial grasses

As Go the Plants, So Go the Animals

My response to the changes I wrote about above (the movement toward Mediterranean climate) is to try and do a better job of matching my animal grazing enterprise to the forage curve I am saddled with. And to me, that means shifting away from cow-calf and much more toward grazing yearling cattle.

Shifting to a yearling enterprise is not really much of a radical shift. We have routinely used yearling cattle as part of our enterprise mix, typically running at around 33%. In many ways I find yearlings to be less labor intensive that cow/calf pairs. For the most part, yearlings are curious and easily socialized. Historically, I have seen fewer health problems with yearlings than with other classes. Of course, this is probably a reflection of the cattle owners I work with.

Moving toward yearlings will mean a shorter, more intense grazing season, and for me, it means a greater dependence on custom grazing. Happily, I have relationships with people who need custom grazing operators for their yearling/stocker calves and their replacement heifers. I feel confident that I can put together adequate numbers of young cattle to match our 100-day yearling grazing season.

And What of the Humans?

The shift toward custom grazing yearling cattle comes with some particularly attractive facets for the humans. I will not be spending two-to-three months accumulating a cow herd each winter. I will no longer be in the hay feeding business, as I will have no cattle to worry about until the yearlings show up on the first day of spring grazing. I will have a vastly reduced period of grazing, although it is possible, I may need to find some adult cows to clean up following the yearling season. My financial risk will fall to zero, as I will not own any of the yearlings.

This last part – the reduction of risk – comes with an attendant reduction in reward. At this point in my life, I am alright with that. And besides, there will be the increased reward of more freedom, more time, more travel. My ranching enterprise will be compressed, leaving more time for the rest of my life. And that sounds increasingly like a good thing.

I find myself looking forward to next year already, even as we are only mid-way through this year’s grazing season. I think that’s a good thing: I’m looking ahead to change.

Happy Grazing!

Thinking About It

Here are questions you can ask yourself to practice thinking through your own challenges.

What is my typical forage growth rate?

Can I put together a diagram like John’s that will help me answer management questions? If not, who can I reach out to in my area who has that experience and can help me learn what I need to know?

Do I know when and how to destock to keep from running out of forage?

What is my drought plan? (Hint: download “Drought Planning 101” for how to create a plan that will protect you in the future.)

What kind of relationships am I nurturing that are mutually beneficial to our lives and operations?

John has created a supportive community to create resilience when times are tough. What can I do to create a similar support system? Are there grazing organizations I can join to find like-minded people?

Your Tips Keep This Library Online

This resource only survives with your assistance.

John Marble
John Marble
John Marble grew up on a terribly conventional ranch with a large family where each kid had their own tractor. Surviving that, he now owns a small grazing and marketing operation that focuses on producing value through managed grazing. He oversees a diverse ranching operation, renting and owning cattle and grasslands while managing timber, wildlife habitat and human relationships. His multi-species approach includes meat goats, pointing dogs and barn cats. He has a life-long interest in ecology, trying to understand how plants, animals, soils and humans fit together. John spends his late-night hours working on fiction, writing about worlds much less strange than this one.


  1. Dear Kathy and John, This is precisely why I appreciate you folks so much. Sharing your stories and experiences that can be difficult to talk about, humanizes the decisions you make, for the benefit of others. I wish I could send our rain to ya and ease the incredible pain everyone in the drought areas are facing. However, the “D” word is getting more attention over here in the East as the extremes can rear their ugly head quite quickly. We’re all blessed to have you inspiring the realities of land management. Thank you. GW

Comments are closed.

Welcome to the On Pasture Library

Free Ebook!

Latest Additions

Most Read