from the unrest-in-the-forest-there-is-trouble-with-the-trees dept.
Wildfires and climbing temperatures have caused a 6.7 percent decline since 1985:
The State of California is banking on its forests to help reduce planet-warming carbon dioxide in the atmosphere. But that element of the state's climate-change solution arsenal may be in jeopardy, as new research from the University of California, Irvine reports that trees in California's mountain ranges and open spaces are dying from wildfires and other pressures -- and fewer new trees are filling the void.
[...] For the study, the UCI-led team used satellite data from the USGS and NASA's Landsat mission to study vegetation changes between 1985 and 2021. They found that one of the starkest declines in tree cover was in Southern California, where 14 percent of the tree population in local mountain ranges vanished, potentially permanently.
[...] The rate and scale of decline varies across the state. Tree cover in the Sierra Nevada, for instance, stayed relatively stable until around 2010, then began dropping precipitously. The 8.8 percent die-off in the Sierra coincided with a severe drought from 2012 to 2015, followed by some of the worst wildfires in the state's history, including the Creek Fire in 2020.
Fortunately "in the north, there's plenty of recovery after fire," said Wang, perhaps because of the region's higher rainfall and cooler temperatures. But even there, high fire years in 2018, 2020 and 2021 have taken a visible toll.
[...] "This threat to California's climate solutions isn't going away anytime soon," Wang said. "We might be entering a new age of intense fire and vulnerable forests."
Journal Reference:
Jonathan A. Wang et al, Losses of Tree Cover in California Driven by Increasing Fire Disturbance and Climate Stress, AGU Advances (2022). DOI: 10.1029/2021AV000654">10.1029/2021AV000654
(Score: 2, Informative) by Anonymous Coward on Saturday July 16 2022, @04:33AM (9 children)
Decades of government fire suppression policy in the West mean that the West has too many trees too close together. It's a tinderbox and not normal for the fire adapted Western ecosystem. Stating that there was some decline in tree cover is a good and NECESSARY outcome. We need more controlled burns or selective logging. These things will reduce the OUT OF CONTROL wildfires resulting from our current unnatural tree and vegetation cover.
(Score: 2, Interesting) by Anonymous Coward on Saturday July 16 2022, @05:36AM (6 children)
There is truth to this. Tree cover is greater than it was perhaps a century ago. That statement is correct.
Fires are a natural part of the ecosystem, periodically burning the area before trees and other plants return and grow again. In normal conditions, trees should return after a fire, though not at the density that has resulted from forest management practices in the 20th century.
The article is suggesting that severe drought may be causing the climate to be unsuitable for any of the trees to go back, instead being replaced by shrubs and grasses. The article also states that even in areas where fires aren't occurring, trees are dying due to the stresses of high temperatures and low precipitation during the severe drought.
The areas being studied shouldn't have as many trees as what has been present in recent decades, and this is due to forest management. However, the areas shouldn't be devoid of trees, either. When fires occur, trees should burn, but should also grow back. The problem is that they're not growing back at all. The forest management practices also don't really explain trees dying in areas that haven't been burned. Basically, there should be a moderate level of tree cover, but instead we're going from one extreme (too many trees) to the other (none).
Also, link at the bottom of the article doesn't seem to work, so here's a link to the full publication: https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2021AV000654 [wiley.com].
(Score: 3, Insightful) by PiMuNu on Saturday July 16 2022, @07:17AM (5 children)
> There is truth to this. Tree cover is greater than it was perhaps a century ago. That statement is correct.
What is your evidence?
(Score: 4, Informative) by Anonymous Coward on Saturday July 16 2022, @07:50AM (4 children)
This is somewhat common knowledge. However, since a citation is requested, I will provide such a citation [wiley.com]. While I hate to link to anything from Elsevier, here is another study [sciencedirect.com].
Also, when you see photos taken from the same place in the Sierra Nevada across several decades and see the forest become much denser, it supports this conclusion.
There are similar issues in the Great Plains. Fires are also a necessary process in prairie ecosystems. When fires are suppressed and the prairie doesn't get burned, the native grasses get displaced by trees.
When the ecosystem has adapted so much to periodic fires, it's not surprising that suppressing those fires changes the ecosystem.
(Score: 2, Insightful) by Anonymous Coward on Saturday July 16 2022, @02:51PM (1 child)
Neither of those links say what you imply.
(Score: 0) by Anonymous Coward on Saturday July 16 2022, @07:21PM
None of your posts mean what they say.
(Score: 3, Informative) by PiMuNu on Sunday July 17 2022, @01:51AM (1 child)
Thanks. Your evidence does not as far as I can see support your conclusion. From the first article:
> Density of small trees (10.2–30.4 cm dbh) was significantly higher in the modern data set for all elevations and all latitudes, ranging from 20 to 148% higher.
> However, density of large trees (≥61.0 cm) was lower in the modern data set for most elevations and latitudes, ranging from 41% to 60% lower in most zones.
> Density difference of mid-sized trees (30.5–60.9 cm) was mixed, but was generally higher in modern plots.
The second article, similarly:
> experience up to 400% regional increases in small tree ( private timberlands, national parks and wilderness areas experience the most extreme change with an average loss of over 83% and 71% respectively.
It would seem that large trees are being replaced by small trees. Looking at e.g. table 3 of the second article, there are more large trees than small trees, which would indicate that the total biomass of tree has decreased in the long term as well as the short term. I have only skimmed the references so I apologise if I made incorrect inference.
> This is somewhat common knowledge.
I can recall a number of examples where "common knowledge" has, upon examination, been shown to be ill-founded. In particular it is my understanding, as a non-USian things which may be well understood to locals are not clear to me. I am however aware that this issue was politicised during the Trump era following a number of severe wildfires in the California region.
(Score: 2) by PiMuNu on Sunday July 17 2022, @01:54AM
I might also add that AC has several times made assertions such as
"This is common knowledge"
"There is truth in this"
without supporting evidence. This immediately makes me doubt that evidence exists.
(Score: 0) by Anonymous Coward on Saturday July 16 2022, @05:44AM
Finally someone uses "ecosystem" correctly.
(Score: 2) by Joe Desertrat on Wednesday July 20 2022, @01:44AM
A lot of the forests in semi-arid areas are remnants of those that sprouted in the melt water of glaciers as the last ice age had its ice sheets recede. The conditions to regrow them are not likely going to occur again for thousands of years, if at all. So clear cut or otherwise unsustainably use them, and they won't regrow. Suppress the part fire plays in the ecosystem, and eventually they will burn disastrously, and they won't regrow. The forests being gone will affect other parts of the ecosystem. Eventually, they will be just more desert mountain ranges.
(Score: 5, Insightful) by Barenflimski on Saturday July 16 2022, @07:09AM (8 children)
All these headlines. Trees Dying, might not come back.
Duh. Climate change is happening.
Need lots of water for lots of trees? But not lots of water? No trees for you.
I hate to always think that the audience of these things is just a fictional idiot, but it has become clear over my lifetime that there are a whole lot of people, so disconnected from how planet earth works, that they think this is some breaking news. I hear them talk about how, "Life will never be the same."
I live in Colorado. The forest have been progressively killed by Pine beetles, decades ago. Anyone who knew anything about how a healthy sprout worked, knew that if your trees were being killed by Pine Beetles, that for the most part, it wasn't the beetles fault, the trees were stressed for reasons outside of the beetles.
So yes. As climate changes, the tree lines, and forests will adjust. Grasslands will move.
(Score: 1, Troll) by PiMuNu on Saturday July 16 2022, @07:14AM (2 children)
Desertification. There are techniques for reversing it, by being selective about species to replant, but it needs active management.
Note trees do make their own rain, so there is a positive feedback loop which may need kick starting, for example in areas where there has been large scale deforestation from forest fires.
(Score: 5, Informative) by Anonymous Coward on Saturday July 16 2022, @08:06AM (1 child)
This is effectively the same line of reasoning as the rain follows the plow [wikipedia.org], and the idea that planting crops in the Great Plains would cause more precipitation. In reality, it's a lot more complicated.
Evapotranspiration does increase humidity, yes. But that's only one factor in precipitation. Heating of dry soil may warm the air faster, causing stronger and deeper boundary layer convection, and perhaps leading to more thunderstorms.
Another factor is that a lot of the moisture for intense precipitation events, both in the Western US and the Great Plains isn't from evapotranspiration in the same area. Much of the precipitation in the Great Plains is nocturnal and is linked with the low-level jet, which produces lift and transports moisture into the region. A lot of that moisture originates over the Gulf of Mexico. In California, most of the precipitation occurs during the winter. Heavy precipitation tends to occur as a result of moisture transported from the Pacific Ocean and orographic lift as the winds ascend over mountain ranges. In either case, the trees and other vegetation likely has a very limited impact on precipitation.
(Score: 2) by PiMuNu on Sunday July 17 2022, @01:57AM
I was actually referring to specific chemicals released by trees to encourage nucleation of rain. I could dig out the reference, it was in Nature family journals a few years back.
(Score: 3, Redundant) by bzipitidoo on Saturday July 16 2022, @12:01PM (1 child)
> Climate change is happening.
That passive voice statement makes it sound solely natural. Yes, there are natural causes of climate change, and yes, the climate always has changed.
> they think this is some breaking news.
No, nothing "breaking" about the news that we've put a heavy hand on why and how climate is changing and where it's going. Been hearing it since the 1980s. Can't call or think that "breaking", and no one does. We've been warned, over and over and over, that if we don't want to accelerate climate change at a speed that, so far as we know, is unprecedented, we have to quit pulling carbon out of the ground.
(Score: 0) by Anonymous Coward on Saturday July 16 2022, @07:25PM
We are not capable of collective action. Whatever the result of everyone acting in their own interest is, is what we'll get.
(Score: 5, Insightful) by Thexalon on Saturday July 16 2022, @05:19PM (2 children)
They'll adjust eventually, but while they're adjusting, us humans won't have enough food to eat. For example, if California loses so much water that it can't do agriculture anymore, then humans in America are going to have to scramble to figure out where something like 1/3 of our vegetables are coming from. If Oklahoma's ongoing dry spell keeps getting worse, it will make the Dust Bowl seem like a picnic by comparison.
Scientists have been warning that this was coming for decades. And the combination of our complacency, companies with $trillions invested in fossil fuels still in the ground determined to get it out of the ground and sell it, and politicians happy to sell public policy to the highest bidder have combined to ensure that we do absolutely nothing useful to stop it. And you can be sure that when things get worse, and they're going to, those same people will tell us that nobody could have possibly predicted these consequences.
The only thing that stops a bad guy with a compiler is a good guy with a compiler.
(Score: 1, Touché) by Anonymous Coward on Saturday July 16 2022, @07:27PM
> humans in America are going to have to scramble to figure out where something like 1/3 of our vegetables are coming from.
No vegetables? Let them eat steak.
(Score: 2) by Phoenix666 on Saturday July 16 2022, @11:00PM
No, we'll be alright. For vegetables we'll do like this old guy in Nebraska [youtube.com]. He's a retired post master, and if I remember correctly, at some point in his tour of his greenhouse he quips that he makes more money selling his produce to local stores than he ever did working for the Postal Service.
There are plenty of other examples of growing veggies in places that are too arid for open-air farming. In the south of places like Spain and Turkey there are huge swathes of land covered in greenhouses.
Humans are routinely terrible at anticipating obvious challenges, but they are decent at solving them once they must.
Washington DC delenda est.
(Score: 1, Funny) by Anonymous Coward on Saturday July 16 2022, @11:08AM (8 children)
If your trees can't take it, AU will happily sell you eucalyptus seeds. Drought tolerant, tough, and evolved to come back after fires.
Also the best firewood in the world, for those of you who still have wood-fired stoves or heating. Damn near as good as black coal, but without the bad smell or smoke.
(Score: 2) by dwilson on Saturday July 16 2022, @01:46PM (7 children)
I do heat most of my rigging with wood, as it happens, most of it with a boiler under computer monitoring and control. It's about as efficient as plain old combustion can be, outside the carefully controlled conditions of a lab or large power plant.
You'll have to help me out with this, it reads like you're going for 'funny' and that's how it's modded currently, but I don't get the joke. I know nothing about eucalyptus, other than to recognize the smell.
Is it a fire hazard down under? Does it contribute to most of their forest-fire problems? Does it grow like a weed, a reverse-invasive-species joke because Australia has had so much trouble importing things that got out of control and they want to return the favour?
- D
(Score: 1, Informative) by Anonymous Coward on Saturday July 16 2022, @03:46PM (1 child)
Yes, this is my take. In California it does indeed grow as an invasive and it's a huge fire hazard. Apparently it's got the BTUs of oak but is more likely to pop and spark. There is plenty of eucalyptus on the coast where it grows well and has the potential to explode during fires. Fortunately it's just a few groves here and there and hasn't become dominant in a huge part of the landscape. It ought to be a crime to grow them inland, if that's possible.
(Score: 4, Informative) by ChrisMaple on Saturday July 16 2022, @04:18PM
According to wikipedia, eucalyptus also sucks a lot of water out of the soil, something California doesn't need.
(Score: 1, Informative) by Anonymous Coward on Saturday July 16 2022, @07:33PM (1 child)
Eucalyptus is somewhat fire tolerant and therefore it has a competitive advantage in areas that catch fire. Which, being the Australian criminal-minded bastard it is, it encourages by dropping flammable bark and oozing nice smelling accelerants.
Of course, MOAR fire is what we are told will solve the, uh, wildfires. That and tin foil hats to reflect the space lasers. Honestly, look, we aren't doing anything about anything. Get used to dying.
(Score: 2) by Phoenix666 on Saturday July 16 2022, @11:04PM
I hiked through the Blue Mountains near Sydney when I was younger and they said that they were called "blue" because of the mie scattering created by the fine shroud of eucalyptus oil that engulfs the forests there. They noted that it made for spectacularly fast wild fires.
So, yes, not trees you'd like to have in California.
Washington DC delenda est.
(Score: 2) by Reziac on Sunday July 17 2022, @02:25AM (1 child)
I think the joke is that eucalyptus are sort of like growing gasoline. High in volatiles and will go up in smoke if you so much as look at them crosseyed. Dandy firewood, all right. Perfect if you want forest fires!
And there is no Alkibiades to come back and save us from ourselves.
(Score: 0) by Anonymous Coward on Sunday July 17 2022, @11:41AM
Actually there are a lot of different eucalypts. You can use the oil as diesel fuel and the leaves contain a lot of it. Bushfires in AU regularly match the wind speed in advancing. 80 to 100 km/h firefronts are not unheard of when the wind is high. There is a lot of energy liberated there, "Black Saturday" was bad enough that the firestorm had lightning bolts in it.
(Score: 0) by Anonymous Coward on Monday July 18 2022, @10:20AM
Yeah, I was sort of going for humorous, but I wasn't kidding about the firewood. Some species of eucalptus are dense enough that kiln-dried timber still sinks in water. As pterry said "You could laugh at the idea of wooden weapons, until you saw the sort of wood they grew there. It's hard to laugh with a boomerang stuck in your ribs."
(Score: 2) by hendrikboom on Saturday July 16 2022, @05:49PM
Without fire, a number of species of trees will not reproduce. Lodgepole pine, for example.
They use fire to release their seeds.