The authors conclude that limiting Earth’s warming will determine survivability for many of Earth’s forests
UNIVERSITY OF FLORIDA
CREDIT: CSABA MÁTYÁS, PROFESSOR EMERITUS, UNIVERSITY OF SOPRON, HUNGARY
How hot is too hot, and how dry is too dry, for the Earth’s forests? A new study from an international team of researchers found the answers – by looking at decades of dying trees.
Just published in the journal Nature Communications, the study compiles the first global database of precisely georeferenced forest die-off events, at 675 locations dating back to 1970. The study, which encompasses all forested continents, then compares that information to existing climate data to determine the heat and drought climatic conditions that caused these documented tree mortality episodes.
“In this study, we’re letting the Earth’s forests do the talking,” said William Hammond, a University of Florida plant ecophysiologist who led the study. “We collected data from previous studies documenting where and when trees died, and then analyzed what the climate was during mortality events, compared to long-term conditions.”
After performing the climate analysis on the observed forest mortality data, Hammond noted, a pattern emerged.
“What we found was that at the global scale, there was this consistently hotter, drier pattern – what we call a ‘hotter-drought fingerprint’ – that can show us how unusually hot or dry it has to get for forests to be at risk of death,” said Hammond, an assistant professor in the UF/IFAS agronomy department.
The fingerprint, he says, shows that forest mortality events consistently occurred when the typically hottest and driest months of the year got even warmer and drier.
“Our hotter-drought fingerprint revealed that global forest mortality is linked to intensified climate extremes,” Hammond said. “Using climate model data, we estimated how frequent these previously lethal climate conditions would become under further warming, compared to pre-industrial era climate – 22% more frequent at plus 2 degrees Celsius (plus 3.6 degrees Fahrenheit), to 140% more frequently at plus 4 degrees Celsius (plus 7.2 degrees Fahrenheit).”
Those higher temperatures would more than double how often forests around the world see tree-killing droughts, he adds.
“Plants do a phenomenal job of capturing and sequestering carbon,” Hammond said. “But death of the plants not only prevents their performing this critical carbon-capturing role, plants also start releasing carbon as they decay.”
Hammond says that relying, in part, upon trees and other plants to capture and sequester carbon, as some proposed climate solutions suggest, makes it is critical to understand how hot is ‘too hot,’ and how dry is ‘too dry.’ “Otherwise mortality events, like those included in our database, may wipe out planned carbon gains.”
One of the study’s co-authors, Cuauhtémoc Sáenz-Romero of Universidad Michoacana de San Nicolás de Hidalgo in Mexico, offered an example of how recent climate patterns affected a Mexican temperate forest.
“In recent years, the dry and warm March to May season is even more dry than usual, but also warmer than ever,” he said. “This combination is inducing a lot of stress on the trees before the arrival of the next June-to-October rainy season. For example, in 2021, more than 8,000 mature trees were killed by bark beetles in the Monarch Butterfly Biosphere Reserve in Central Mexico. The effect of the La Niña Pacific Ocean stream resulted in drier, warmer conditions; a deadly combination that favored pest outbreaks.”
Hammond has also developed an interactive application on the website of the International Tree Mortality Network to host the database online and to allow others to submit additional observations of forest mortality to the database.
EXPLAINERS
‘Georeferenced’
Using maps or aerial images, scientists assign to them real-world coordinates.
‘Ground-truthed’
Information confirmed or validated by direct observation and measurement. In the case of machine learning, it refers to checking results for accuracy.
The organization, founded and coordinated by co-author Henrik Hartmann from the Max Planck Institute in Germany, among others, is a collaborative effort between scientists on every forested continent and aims to coordinate international research efforts on forest die-off events. Hammond is the network’s data management group leader.
“We’re hoping that this paper will create a bit of urgency around the need to understand the role of warming on forest mortality,” Hammond said. “Also, we expect that our open-access database will enable additional studies, including other climate fingerprints from local to regional scales. Current climate modeling and remote-sensing research communities need ground-truthed datasets to validate their predictions of important processes like forest mortality. One of the really important elements to this study was bringing all this data together for the first time, so that we can ask a question like this at the planetary scale.”
The paper, “Global field observations of tree die-off reveal hotter-drought fingerprint for Earth’s forests,” will be available at nature.com/articles/s41467-022-29289-2 . In addition to Hammond, Sáenz-Romero and Hartmann, it is also co-authored by A. Park Williams, University of California, Los Angeles; John Abatzoglou, University of California, Merced; Henry D. Adams, Washington State University; Tamir Klein, Weizmann Institute of Science; Rosana López, Universidad Politécnica de Madrid, Spain; David D. Breshears, University of Arizona; and Craig D. Allen, University of New Mexico.
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The mission of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is to develop knowledge relevant to agricultural, human and natural resources and to make that knowledge available to sustain and enhance the quality of human life. With more than a dozen research facilities, 67 county Extension offices, and award-winning students and faculty in the UF College of Agricultural and Life Sciences, UF/IFAS brings science-based solutions to the state’s agricultural and natural resources industries, and all Florida residents.
ifas.ufl.edu | @UF_IFAS
JOURNAL
Nature Communications
DOI
METHOD OF RESEARCH
Data/statistical analysis
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Global field observations of tree die-off reveal hotter-drought fingerprint for Earth’s forests
ARTICLE PUBLICATION DATE
5-Apr-2022
This reads like the kind of nonsense we get when “researchers” don’t get out into the natural environment, all over the earth, to see what a grand variety of “forests” there in a great variety of environments. “Ground Truthed” probably they went to the park one day.
And the people from the University of Florida know that citrus orchards have had to move south and continue to do so, partly because the weather in SE U.S. is getting colder.
Exactly – read carefully the difference between the 2 statements – the alarmist zealot is claiming heat and drought as the sole cause whilst the real world data referenced by the chap in Mexico indicates that it’s pests that favour warmer, drier conditions that are the problem. Better pest control measures would appear to be the solution, not whining about a trace gas.
Junk model. The comparison given is between “die-off events” and temperature. This kind of model is under-specified, a type of logical and scientific fallacy.
There are dozens of factors that influence forest mortality including insects, diseases, excessively cold conditions, excessively wet conditions, forest dynamics, tree age distributions, competitive species, animal damage, wind storms, and FIRE to name a few. None of these are considered in the model. Their influences are ignored. Instead, output from another model, a climate model, is the only explanatory variable used.
Regardless of the model “fit”, it’s a junk model. Under-specified, illogical, unscientific: it looks like science but it’s not. Charlatans misuse this model to promote climate alarmism. It’s agenda-driven fake science.
Is this point you make about the model being under-specified the sort of thing that should be picked up at peer-review time (or even before)?
Indeed, this is single parameter attribution, for a multiparameter cause.
So bark beetles are climate change?
Bark beetles are always around our pine forests. But they tend to damage or kill the trees only when the trees are already stressed, such as during extended periods of drought, or there are too many trees competing for limited sun exposure or soil nutrients, or in older “climax phase” forests as part of their natural life cycle. So yes there is an effect from climate. But all climates are subject to variation, entirely natural. All forests tend to wax and wane, and natural climate variation is part of the explanation why.
“or there are too many trees competing for …”
e.g. forest mismanagement like suppressing fire in the Sierra Nevada. Then we discover Paiute forest management practices worked. But we’re still stuck with enviro-wacko practices.
Bark beetles rarely disturb young growth. Until the tree is old enough for the bark to become deeply fissured bark beetles have little access to the cambium layer.
Woodpeckers along with other stressors may enable the beetles to reach the cambium layer easier, but that means neither drought nor heat killed the trees.
Nor do bark beetles bother with trees already dead. They do not support the beetle’s lifecycle.
Yes. I lived in Idaho in the 1980s when the predominant lodgpole forests in that area were reaching the climax phase of maturity, near 200 years old. Pine beetles ravaged the lodgepole forests that were in the climax phase, but largely left alone other types of forest such as ponderosa pine or douglas firs at the same time
The result was lots of beetle-killed forests, and the USFS encouraged logging and removal of those “snags” or dead trees by firewood harvesters in order to reduce the fuel load of drying dead trees. Near the end of the decade (1988) was when a massive wildfire burned out a large section of Yelowstone Park, which again was where the forests were predominantly old mature lodgepole. About 36% of the park was burned out that year. It will be somewhere around 50-70 years from now before those areas begin to resemble the pre-fire forest cover.
A lot of people were very angry at the destruction in Yellowstone NP, and while it undoubtedly was made much worse by the policies of NPS to not thin out the forests, it was probably inevitable anyway because of the age, maturity, and bark beetle infestations.
OMG. Authors conclude — too hot — too dry — too windy — too too too too. This is all based on the fraudulent demonization of CO2, even though CO2 is the foundation of life on earth — and we need more of it … https://www.youtube.com/watch?v=zVRVopDdNyg
Good video.
Balloon and Satellite temperature data say the world stopped warming after the false Y2K panic. Don’t these people look at the data?
That’s the point. Reality is irrelevant to the main stream media. Propaganda is the order of the day. Big Brother insists you only see the their data … https://www.youtube.com/watch?v=hs-K_tadveI
Forests are expanding and the earth is greening, so wherever trees are dying of drought (a continuous process) more trees elsewhere are thriving.
Moving on
Yet another example of warmunist static thinking.
All forests evolve constantly due to changing climate as well as the natural wildfire and natural growth cycles of the dominant tree and understory species. The stupid warmunists look at a forest in a snapshot of time, declaring that that particular mix and condition of plants is supposed to stay the same forever, and therefore any change is “bad” and due to human activity.
The predominant lodge pole pine forests of the Rocky Mountain states go through a relatively short life cycle of about 200 years, endlessly repeated until the climate changes. Other types of forest have much longer life cycles, such as Pacific redwood forests because the trees are much longer lived. Periodic wildfires are key triggers to starting a new cycle.
Longer term, the climate has always changed, and forests and the trees and understory within them change and thus adapt to whatever the climate is doing, by natural selection, of course. When the climate gets wetter, the forest becomes dominated by certain tree types such as firs, Cypress, mohogany, and hardwoods, with dense understory of plants that require lots of moisture but relatively little sunshine due to the dense canopy .. plants like ferns. But when the climate gets drier, the forest thins out, much of the canopy disappears, trees like ponderosa pine or scrub pine take over, and much of the understory gets replaced by sun-loving savanna grasses and shrubs. Both kinds of forest “love” their climate because that is what they are adapted to.
It’s called “natural selection”.
Apparently, in order to be a card carrying warmunist one also has to be an evolution denier and a flat earther. While they all claim to be scientifically literate, which of course is a huge laugher!
”Yet another example of warmunist static thinking.”
My thought exactly. Coral reefs are seen the same way. ”Whatever is here now should be here forever or something is ”wrong”
It’s actually quite infantile.
It never ceases to amaze me that the warmunists totally ignore extremely well established natural changes in climate, geology, and in dominant plant and animal species that are fantastically more radical in scale and nature than anything any human has experienced since civilization began
Like uhhh, how about those 26 glaciation/interglacial cycles within the last 2.6 million years of the Quaternary/Holocene period … which is but the tiniest blip in the geologic history of our planet?
In human timescales, everything appears on its surface to be more or less static, such that the normal, within the noise level temporary climate cycles lasting decades to hundreds of years appear dramatic, yet clearly are not relative to the earth’s history of constantly changing climate. It’s difficult for humans to comprehend even human timescales. Such as the fact that human civilization has existed for a mere 10 thousand years, give or take … which amounts to about 500 human generations. How many Americans, for instance, can trace their own family lineage back more than half a dozen generations .. and even that seems long long ago.
What the heck is a “scrub pine”?
I definitely know it’s not a woman & I’m not even a biologist!!!
(small pine with short needles of E US, often with twisted branches)
I know it’s not a woman & I’m not even a biologist!!!
(small shrubby pine with short needles of the E US, often with
twisted branches)
The key indicator is “no central leader”. Many of the smaller trees have a trunk that grows at substantial opposing angles.
Many of the other bushes and trees growing in their locales are various forms of “scrub“.
Meaning, any stunted pine tree could be referred to as a “scrub pine”.
When I was growing up, we took frequent trips to the New Jersey shore. Substantial portions of those trips were through what are called the “Pine Barrens”.
When I was old enough to drive, I stopped in their midst at a few places. I was taller than the whole forest.
Walking through the pine barrens was difficult, at best. Deadfall, twisted trees, the ground covered with small trees making putting a foot down. People referred to those pines as “scrub pines”, though they’re not the same as Virginia or Florida pine trees.
I’ve also heard people refer to stunted pine trees growing on rocky tops on some East Coast mountains as scrub pines. Pines being a descriptive adjective to the noun scrub.
Scrub pine is a type of pine that tends to grow in more challenging environments such as high mountains or in dry areas that don’t readily support other types of pines such as lodgepole, longleaf, ponderosa, and other evergreens that grow in dense stands like douglas firs, etc. The species name is Pinus Virginiana.
How is this article reconciled with the actual observation of the greening of the planet?
You’re not supposed to know that. Just like we’re not supposed to know about the temperature pause … https://www.youtube.com/watch?v=CBnzmCJALYk
Thanks for the graphic. I had seen it before but forgot to save it. I hope to be
able to return the favor.
Here are graphics of forests & extreme deserts from 18kya, 5kya, & ~20ya.
(The CO2’s <200ppm, a bit >200ppm & a bit <400ppm. The first was in the
last ice age, the second in the Holocene Maximum, & the last having been
through the LIA after the MWP, with the rise in CO2 relatively recent.
Sources: I don’t have one for the 18kya T graph but here are the rest:
11kT- FAR section 7.2 or CO2science
https://archive.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_07.pdf
http://www.co2science.org/subject/other/figures/temp10000.jpg
https://atoc.colorado.edu/~toohey/overheads.html
It’s amazing how higher temperatures & more CO2 are good for us & not bad
as The Team™- a bunch of nasty lying jerks- want us to believe!
18kya T
11kya T
Thanks for the graphic which I’ve seen before but forgot to save. Hopefully,
I can return the favor. I have graphics of forests & extreme deserts from
18kya, 5kya & ~20ya when CO2 were <200ppm, ~270ppm & ~400ppm, with
the rise being recent. The first is in the last Ice Age, the second in the
Holocene Optimum, & the last in the current warm period that was preceded
by the LIA.
Sources- I don’t have one for the 18kya T but I do for the rest:
5kya T- FAR Sec 7.2 or CO2Science
https://archive.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_07.pdf
http://www.co2science.org/subject/other/figures/temp10000.jpg
https://atoc.colorado.edu/~toohey/overheads.html
As you can see, higher temps & more CO2 are beneficial to mankind, not
harmful as the nasty, lying Team™ would have us believe!
18kya T
MODS: HELP!
I have a reply or two to Dan Pangburn awaiting approval- Could you
please check on it/them? Thanks. (If two, please delete the first & post the
second.) Then delete this if you need to.
Here’s my third try to post as I’m having some problems. This time I’m
going to try to post it on several posts. The 11kya that did post should follow
my last post here.
Thanks for the graphic which I saw before but didn’t save. Hopefully, I can
return the favor. I have three graphics of forest & extreme desert from 18kya,
5kya, & ~20ya, when the CO2 were <200ppm, ~270ppm, & ~400ppm,
respectively, with the last one’s rise quite recent. The first is from the last ice
age, the second from the Holocene Optimum, & the last from the current
warm period which followed the LIA.
Sources: I don’t have one for the 18kya T but do for the rest:
11ky T- FAR sec7.2 & CO2Science
https://archive.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapter_07.pdf
http://www.co2science.org/subject/other/figures/temp10000.jpg
https://atoc.colorado.edu/~toohey/overheads.html
It turns out that warmer temperatures & higher CO2 are actually beneficial
for mankind instead of harmful as the corrupt Team™ tries to force us to
believe!
18kya forests & deserts
5kya forests & trees
~20ya forests & deserts
18kya T
It does not reconcile. Apparently, the authors only looked at the process of dying, not at the processes of living and growing. Necrotrophic “scientists”.
Whether a healthy tree survives or dies could well depend on what happens of a time period of hours or less. If it is stressed by excessive heat and dry conditions, it can be saved by a half hour of heavy rain, for example. Conversely, when near death, a half hour burst of hot, dry wind can cause death.
Having read the paper, I did not see any consideration of this time factor. The paper is too coarse in its parameters, seeming to consider that monthly or longer times contain the seeds of damage. Also, there is a lot of nonsense stemming from convoluted definitions of heatwave in the general literature, designed to combat the raw data truth that in many places heatwaves are nor becoming longer, hotter or more frequent, contrary to the Establishment mantra.
In Sunday School we were taught to build upon the rock and not upon the sand. This lesson seems missing from this paper, where little rock-like hard, raw data are apparent.
Geoff S
They are looking for what caused “die back”. But equally, surely, what caused the re-growth that left the forests still in existence?
The analogy is the Great Barrier Reef, and many similar reefs – die back and then recovery. Are there any forests that have completely ‘died back” within the last 1000 (or 2000) years, other than those used for ship building or the spread of towns?
Where I grew up, there was the great North Wood. Now just a memory in the suburb’s name of “Norwood”.
Cincinnati?
They’re not looking for a cause for “die-back” – they know the cause and are twisting the data to fit. Fraudulent unscientific practices at their worst.
“Are there any forests that have completely ‘died back” within the last 1000 (or 2000) years, “
The complete die back I’m familiar with is the retreat of the northern tree line from its northernmost extent during the medieval warm period to its current position much further south. Due of course to colder temperatures we are only now emerging from.
“In this study, we’re letting the Earth’s forests do the talking”… Followed by, “Using climate model data, we estimated…” Thank you forests, we’ll take it from here!!!
Haven’t read all yet but this statement seems to miss the big picture. Forests and entire ecosystems are dynamic not static (as so many of todays ”scientists” seem to think). They move around. They travel up and down mountains, they travel north or south or east or west according to rainfall and temperature patterns. Over time this can mean hundreds or even thousands of miles. If they can’t go any further they die out. All completely normal and has been happening ever since life began.
There is no need for human intervention but for some reason modern people have a need to preserve what they know forever. Sorry, it doesn’t work that way and you can’t do it anyway.
And on a longer time scale, when a mountain range wears down to a peneplain, all the former elevation-controlled biomes disappear.
With respect to the man himself….
This is ‘Jim Steele Science‘
These folks have visited an empty stable and told us all about it but without giving, or having, any sort of clue as to why the poor old nag bust the door off its hinges and did a runner.
The trees died of starvation – strictly= Nutrient Deficiency
Just like many members of the human population suffered and died from Wuhan Flu just recently. The Flu didn’t kill them, a piss-poor diet took them down, or in the medical vernacular: Co-morbidity
The trees are trying to tell us something but, as obsessed as we are with our own cleverness, we don’t see the simple underlying message/truth
”The trees died of starvation – strictly= Nutrient Deficiency”
”The trees are trying to tell us something”
Do tell!….
I don’t know about Cedar drought in Morocco but isn’t “Global Warming” supposed to generally cause a bit more rain and a bit longer growing season in Temperate and Boreal forests?
Here is die-off event that does not fit the alarmistic narrative: left Haiti right Dominican Republic
From the Middle Ages until the 19th century a huge deforestation took place in Europe, the coal mining industry turned this around into a huge reforestation, But now that virtually all coal mines are closed, a massive deforestation is happening for “renewable biomass”.
That is the real danger for todays forests.
Be warned of a very cold April in eastern Canada and the northeastern US.
It makes you wonder how trees managed to survive hundreds of millions of years unless you happen to believe climate variation is nothing new.
Isn’t there an opportunity here to employ vast numbers of idiots to work as tree counsellors, sitting down to discuss the issues trees have with them. Oh wait…
Talking to plants helps them grow – even talking climate nonsense.
More data mining pretending to be science.
Looking for scientific support of their “climate change” claims – where there aren’t any.
How dumb is too dumb, and how idiotic is too idiotic for so-called “climate science” is what I want to know.
Their models say they’re right, so they must be.
This speculation is all based on temperatures rising as CO2 amounts increase in the atmosphere.
First of all, there is no evidence CO2 is the control knob for temperatures, and second of all, it is currently cooling, not warming. Alarmists have the idea that trends go on forever when it comes to CO2.
And then there is the Early Twentieth Century where it was just as warm as it is today, so places like the United States have been in a temperature downtrend since the 1930’s.
After the hot 1930’s, CO2 amounts increased, but the temperatures cooled by about 2.0C by the time we reached the 1970’s. If history is any guide, we may now be in a similar cooling phase.
Unfortunately, alarmists don’t pay attention to unmodified history so they go off on the wrong track and assume too much.
Once again, the increasing evaporation caused by rising temperatures and the wetter global climate predicted as a result of that is not mentioned. La Nina, a completely natural phenomenon, is cited in Mexico though.
So there you have it again. Climate change theory causes increased precipitation and a wetter world unless it’s causing increasing droughts at the same time.
Imagine that!?
A one size fits all, death index.
How amateur of them!
Multi-acre clusters of dead trees favored by lots of conspiracists lie south of New Orleans.
Acres of standing trees with the local news occasionally speculating what caused the die-off.
What killed the trees was a drainage ditch dug across the fresh water drainage into Lake Borgne. A cut that allowed salt water to replace the fresh water, which the trees were not able to tolerate.
The map function appears to document lots of isolated tree deaths. The map itself documents the area as green
If it’s too hot for trees, why is the area immediately surrounding still green?
“global team of scientists”…that last word sez it all. Grifters is more like what they truly are. Must be some more grant money out there somewhere to keep the scam going.
What won’t they think of next?