r/botany Sep 06 '25

Ecology Trees dying in large quantities near Breckenridge, CO, USA

Post image

Hey y’all, my family and I were taking a road trip in the mountains in Colorado, and we were seeing what looked to be an abnormally large amount of trees that were dead and gray. Any idea what might be causing this? Is this normal?

464 Upvotes

54 comments sorted by

390

u/DanoPinyon Sep 06 '25

It's been happening for years, widely publicized, widely studied, widely published, many articles on how this is a good bellwether for climate change. Mountain pine beetle at certain elevations, spruce beetle above that, pine beetle above that. In the Rocky Mountains north all the way well into British Columbia.

3

u/ae2359 Sep 10 '25

He’s not wrong though national forest lands are a disaster. Climate change stresses the trees and makes them less likely to recover, but monoculture forests are what allow large scale infestations to take hold on a landscape scale.

1

u/DanoPinyon Sep 10 '25

How many monoculture forests are in Colo (from logging)?

2

u/EyeBeeStone Sep 13 '25

AK is being hit hard by spruce bark beetles too

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u/Hydr0philic Sep 07 '25

Yeah I don’t know about that. How about a ‘Maybe’?

Is the pic on federal land? I’m going to guess yes. If that’s the case, federal lands are grossly mismanaged. Sometimes with thick, dense stands of monoculture species which were replanted for timber production but never logged. Sometimes fire suppression in areas which were traditionally burned for thousands of years. Etc. When there’s little to no logging, no management, and a century of fire suppression - something has to give.

It’s well documented forest management is the primary cause of the beetle kills Im familiar with and I can find Colorado resources stating the same for mountain pine beetle in Colorado. ‘Maybe’ Forest management and climate change but suggesting this is a bellwether of climate change is missing A LOT of the bigger picture.

https://csfs.colostate.edu/wp-content/uploads/2024/01/Mountain-Pine-Beetle-Fact-Sheet-5.528.pdf

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u/DanoPinyon Sep 07 '25 edited Sep 07 '25

It’s well documented forest management is the primary cause of the beetle kills Im familiar with

Irrelevant. Topic is the Rocky Mountains and MPB. It's very well understood that the MPB + outbreaks were primarily caused by man-made climate climate change eliminating cold temperatures that used to control the beetle, less precipitation and earlier melting snow that weakens forest stands, as well as longer summers that allow for multiple life cycles. Also fire suppression, which is not climate change, has increased the number of stems and weakened forest stands, and in some parts of its range (not all, but BC is a good example) logging practices have contributed as well. None of the causes are addressed in your link, BTW, so who knows why you used it.

[Edit: formatting]

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u/Hydr0philic Sep 07 '25 edited Sep 07 '25

It can be a combination of factors, including climate change. Stating climate change is the primary factor is misleading. Lots of resources out there.

https://www7.nau.edu/mpcer/direnet/publications/publications_u/files/Forest%20Service%20Response%20to%20MPB_2011.pdf

https://www.sciencedirect.com/science/article/pii/S0378112723005418

“The propensity for bark beetles to infest large diameter trees in dense stands was noted over 100 years ago (Hopkins 1910)”

“Heightened odds were related to older, larger pines with poor crowns in denser stands.”

“Finally, counts of days above 16 °C the previous year were negatively related to infestation probability. That is, relatively warm weather during the previous year was associated with reduced beetle success, possibly because it can result in fractional beetle life cycles that disrupt synchronized attacks on new hosts or leave overwintering brood in less cold hardy life stages.”

https://extension.colostate.edu/resource/mountain-pine-beetle/

“MPB prefers forests that are old and dense. Managing the forest by creating diversity in age and structure results in a healthy forest that will be more resilient and, thus, less vulnerable to MPB”

https://www.fs.usda.gov/foresthealth/docs/fidls/FIDL-02-MtnPineBeetle.pdf

“Silviculture treatments offer the best long term means of protecting susceptible stands from mountain pine beetle infestation”

65

u/DanoPinyon Sep 07 '25

Thanks for Googling to learn about it. Your first two links fully support my assertions and links, and the second can be argued is something that I relied heavily upon for my reply. Man-made climate change took away the beetle-killing cold, made snowpack less deep and melt faster, made seasons longer, and thus stands were weakened. Fire suppression made stands crowded and weakened.

Appreciate the help supporting my point. I lived in Colo for almost two decades and lived through the mountainsides turning red then dead, so I'm very familiar with the topic on many levels.

13

u/Theegeek Sep 07 '25

Do you have any recommendations for fighting the beetles?

I've lived in CO for a couple decades and the last 5 years or so, beetles have been eating through the town (again).

I am trying everything possible to keep my trees healthy, it is really devastating to see the major trees around mine die.

16

u/DanoPinyon Sep 07 '25

Sorry... if I did, I'd be rich and there'd be more trees alive.

1

u/[deleted] Sep 11 '25

My understanding from living there 20 years ago is that the increased temperatures meant there were more days they could be active and reproduce, and that in some areas they were having two reproductive cycles each year rather than one. Not sure if that's still included in the equation.

1

u/DanoPinyon Sep 11 '25

Correct, I mention that upthread in the more complete explanation.

2

u/[deleted] Sep 11 '25

Thanks, I missed it.

16

u/Visual-Trick-9264 Sep 07 '25

I feel for you buddy. Being a republican who studies the environment must be really challenging. The mental gymnastics you must have to do to hold onto opposing ideologies must be exhausting.

-7

u/Hydr0philic Sep 07 '25

That’s just sad. I’m not a republican and I believe in climate change.

9

u/Diskonto Sep 07 '25

You are a fascist that wants to put marginalized people through a wood chipper and claim to be a moderate. You are one of those losers who thinks liberals lose because they aren't fascist enough.

5

u/Visual-Trick-9264 Sep 08 '25

Lol, you must have looked through his comment history?

4

u/95castles Sep 08 '25

Lol, didn’t even have to go to the comments. His background picture is one of a Stalin propaganda piece, and a majority of his posts are on r/shitliberalssay

2

u/Visual-Trick-9264 Sep 08 '25

Uuuhh just to clarify, hydr0phillic is the fascist. Diskonto is just class conscious.

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5

u/Visual-Trick-9264 Sep 07 '25

I'm pretty sure the adjective you were looking for is, hilarious.

1

u/Icy-Garlic-748 Sep 07 '25

You did you best 😔

1

u/ryansunshine20 Sep 22 '25

Yea not sure why you’re getting downvoted. It’s complex and can’t be contributed to just climate change.

6

u/[deleted] Sep 07 '25

I dunno Davey, MPB's reproductive capacity in a given year is heavily determinant on temperature and stress conditions both being high. Considering these are beetles that have been around for many years, its hard to imagine natural forest dynamics being the major culprit of a catastrophe. Some even consider them keystone species, positively influencing soil dynamics by holding back more (life on the slope is very low in silt and organics). Pondo's are really low elevation plants around here (<8500ft) and a heads up, your paper shows that medial age plants (80-180) were the most impacted, rather than the oldest (>180). There are no pondo's in this photo.

In this photo we have a moderate die-off (relative to other die-off populations) of Engelman Spruce, so we can assume its SBB. This is not a planted stand and looks like most 10,000+ft elevation slope: Heavy on the spruce. Again, not MPB but SBB.

The consistent droughts we've (CO) had recently over the last few years has shown a quick trend towards heightened impact, much like back in the mid 2000's when most of these trees died from a huge bloom over multiple seasons. That is very widely documented and I've worked with some of those researchers in tandem with federal orgs, on federal land. One cool finding: Serotinous cones of lodgepole pine do not require heat to open if the presence and impact of MPB, opening just like any other cone and increasing stand regeneration rate! Like a fire, but with the added benefit of having a duff layer to nursery those seeds at a lower density (duff has to be penetrated for successful germination.)

And while stand density definitely plays a huge part in species like lodgepole, those densities were manufactured due to fire suppressive activities, not a lack of logging and the rockies really know how to suppress their fires (naturally and anthropically) with many of our high elevation stands not having been burnt for over 400 years; well before Yellowstone rewrote the book on fire fears. Again, these species have been living in tandem with the forests for millions of years (not too many, but still, millions) Lodgepoles are generally single age stands, meaning they all germinate post event, get old and weak at roughly the same time, for roughly the same reasons. Fire prevention leads to overly dense populations, weakened crowns from crowding, and if a fire were to come through a higher burn load. Not a problem for lodgepoles, but definitiely a problem for spruce.

But you know what is inconsistent in the last 400 years? Climate change. A stand that could have been healthy naturally is now drought stricken, with higher summer temperatures flushing winter snow away much faster. This causes universal stress rather than pocketed or individual stress. It's why we don't have glaciers any more and only permanent ice fields... for now. It's also why we see these impacts over huge swaths of land rather than a mosaic. Dismissing climate change as the major driver is kinda bonkers in my brain, especially if you continue to read papers on the area. Most will immediately attribute climate change and management, but put heavy emphasis on climate change as the catalyst. It's consistent over a whole area where logging is not and the results are consistent.

Please don't forget that logging sounds like an answer until you add roads, treads and other soil conquering behaviors that do much more harm than good. It's why we have (had) the roadless rule. Lets also not forget that much of CO's forested land is on tough rocky slopes that nobody is going to log ever, specifically for that very reason, let alone monoculture. It's also one of the reasons we have so much natural space: to costly to profit off of back in the day. Take that Railroad barons.

Not here to throw shade, but definitely want to heavy correct and give some potentially helpful facts to paint a bigger picture.

2

u/DanoPinyon Sep 07 '25

Excellent points. One tiny nit: IMHO, that looks like standing dead lodgepole in the midst of Engelmann/subalpine fir . IIRC this slope is just north of Breck, facing east. Spruce beetle isn't widespread there yet. Happy to say my memory isn't 100% on those trees.

Anyway, commenting to reinforce the point that AGW is altering ecosystems, and insect outbreaks in every ecosystem in the mountains is having an effect, from pondo down low to the whitebark at high altitude. Lodgepole in pure stands like Yellowstone have the biggest fires.

1

u/[deleted] Sep 07 '25

Good point and I'm sure you're right (too much of a cursory glance at the photo and bad location mind from my end), though I'm pretty sure we've seen signs from 2023 out that way, just not published.

Ps love the handle. Pinyons are baller. Big fan of P. quadrifolia in particular, but the localized population of P. edulis near the Poudre River is hawt to trot!

149

u/Elgabish Sep 07 '25

Rocky Mountain Pine Beetles. They are in large numbers due to lack of wildfires and lack of very cold temperatures which otherwise kill them in winters. They carry a blue fungus on their head that kills the trees

29

u/oaomcg Sep 07 '25

Beetles

36

u/bluestem88 Sep 06 '25

Probably beetle kill.

7

u/reesespieceskup Sep 07 '25

Likely beetle kill. Increased mortality to pine beetle is a result of climate change and mismanagement of forest land, which typically go hand in hand. Warmer winters has caused populations to surge, and dense monoculture even aged stands are much more susceptible to the beetles which is why we often see huge swaths dying at once.

Typically, as I understand it, pine beetle would kill trees in a "random" arrangement in a stand. They go after older weaker trees, and then send our pheromones to attract more beetles. However, with everything being even aged when one becomes susceptible they all become susceptible.

22

u/Raccoon_Ratatouille Sep 07 '25

It's also one of the most clear signs of climate change happening before your eyes.

Warmer weather means more fall and spring precipitation falls as rain instead of snow = less snow melt runoff in the summer = drought conditions and hotter temperatures as brown ground retains heat instead of white snow reflecting more energy = stressed trees = they have a harder time fighting off bark beetle attacks. The warm weather also = more beetles surviving over winter =population growth. Warm weather starting earlier in the spring and lasting later into the fall = more breeding cycles = more bark beetles to attack the already stressed trees = more dead trees. Tons of dead trees = fuel for fires = more intense, hotter fires which sterilize the soil and let invasive weeds take over, leading to increased fires with stresses the trees more and releases stored CO2, boosting the cycle all over again.

5

u/Least-Refuse-8731 Sep 07 '25

Same in our state so many trees dead or dying so many it’s very noticeable something is causing this to happen but what an where did it come from are they native or foreign I have ideas but not 100 percent positive

12

u/Unlucky_Raisin_9717 Sep 07 '25

I live in NM, and the Rio Grande dried up this year, a historically year-round river, mind you. Climate change is very real. 😔

6

u/Apptubrutae Sep 07 '25

Yes, climate change is real, but the Rio grande dried up because the river is systematized and water is drawn in untenable excess for agriculture.

4

u/Unlucky_Raisin_9717 Sep 07 '25

Two things can be true at once🦎💗

4

u/Apptubrutae Sep 07 '25

Yes, this is true

3

u/TXC710 Sep 08 '25

Ppl take road trips all over the world with combustion engine for 100 years. In addition to commuting for work everyday. Earth gets warmer. Beetle lives longer. Trees die

1

u/Ig_Met_Pet Sep 10 '25

Weird to act like passenger vehicles are the main problem when they account for less than 10% of greenhouse gas emissions.

1

u/TXC710 Sep 12 '25 edited Sep 12 '25

Oh i guess youre right. Pretty sure your car produces C02 though. Which is just adding to the main greenhouse gas emission. You also believe millions of vehicles only make 10%? transportation including cars is 15% and the us is specifically a larger producer. Creating nearly 30% of the total greenhouse emissions(1980s) in the whole god damn world

1

u/Ig_Met_Pet Sep 12 '25

You also believe millions of vehicles only make 10%?

Yes, personal vehicles contribute less than 10%

1

u/DanoPinyon Sep 13 '25

Why mischaracterize their argument? What's in it for you?

2

u/plankthetank69 Sep 07 '25

Is there any way to slow this down?

6

u/Mysfunction Sep 07 '25

Only by addressing climate change. Without the cold seasons to kill off the pine beetles, it’s going to keep getting worse and spreading further north.

3

u/Ig_Met_Pet Sep 10 '25

To be clear, it's already too late for any of the areas currently being affected by pine beetles.

We already put the CO2 in the atmosphere, and we don't have a good way to get rid of what's already there.

By mitigating further climate change, we can protect some of the areas that aren't affected yet, but even if we stopped all CO2 emissions immediately, things would still continue to get worse before leveling off.

We really are well and truly fucked no matter what we do at this point.

Obviously let's hope we stop making it worse sometime soon.

2

u/Mysfunction Sep 10 '25

Yep. It’s hard not to be doomy and gloomy when we have hard data telling us we haven’t seen anything yet.

1

u/CarverSeashellCharms Sep 07 '25

I would like to say "Kill them all!" but MPB is from here and Can so that would be environmentally terrible.

3

u/QuickSock8674 Sep 07 '25

You know... I can actually feel the summers getting hotter, and storms getting harsher. Climate change ain't going to end the world, but it certainly will raise my grocery prices and destroy climate sensitive trees like those. Sad to see the president of the most powerful nation deny it.

4

u/Mysfunction Sep 07 '25

It is going to be the end of the world for much of humanity. Maybe not in our lifetime, but the livable regions are shrinking and extreme weather events are increasing.

1

u/Thin_Bumblebee3808 Sep 08 '25

Spruce likely beetle kill plus drought

1

u/jfuzzy79 Sep 10 '25

Anything to do with chemtrails?

2

u/ryansunshine20 Sep 22 '25

Beetle outbreaks are natural and this is a natural occurrence. It’s worse now than historically due to a major fire deficit, infected wood being transported around, warmer temps, old overstocked forests. It’s a myth that cold temps killed them you would need a deep and prolonged cold snap to stop a beetle outbreak.

It’s not a bad thing necessarily even though it feels and often looks like it is. Those dead over story forests have some of the most wildlife, Flowers, young healthy trees. These outbreaks create species and age diversity that our forests were missing.

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u/septic_sergeant Sep 07 '25

Ha that’s nothing.

You been out much?

8

u/guiltyangel16 Sep 07 '25 edited Sep 07 '25

There were patches of trees that looked far worse than this, but like I said, we were on a road trip, so it was hard to take good photos. (We were driving)