This new paper by Kempes et al published in the journal Plos One adds uncertainty to the already uncertain science of dendrochronology dendroclimatology and the attempts at tracking temperature from tree rings. According to this BBC story:
They found that a 2C (3.6F) increase resulted in the average maximum height of trees shrinking by 11%, while a 2C decrease in the nation’s average temperature saw a 13% increase in the predicted maximum height of trees.
Here’s a figure from the paper showing height change with temperature:
The BBC story continues:
“This looks at the basic physics affecting a tree, such as internal fluid flow and the structure of the canopy,” he told BBC News.
“We really wanted something that was based in those mechanisms but at the same time was, conceptually, relatively simple.”
He said tree branches formed a fractal, which meant that if you effectively cut off a branch and then enlarged it, it looked like a whole tree.
“If you nail down that network structure correctly, then you can use it to predict how things change with size.”
From this framework, the team then incorporated local meteorological data, such as rainfall and mean annual temperatures, to allow them to predict the maximum height of trees in the area.
When compared with official data collected by the US Forest Service, the team found that their predictions tied in closely with the actual measurements.
Clearly, there’s more to tree growth than a simple linear relationship with temperature, and this finding shows an inverse relation with temperature to tree height. Maybe this is why Briffa had to truncate uncooperative tree ring data post 1960 and Mike’s Nature trick was used to “hide the decline”.
Here’s the paper abstract, link to the full paper follows.
Predicting Maximum Tree Heights and Other Traits from Allometric Scaling and Resource Limitations
Christopher P. Kempes, Geoffrey B. West, Kelly Crowell, Michelle Girvan
Abstract
Terrestrial vegetation plays a central role in regulating the carbon and water cycles, and adjusting planetary albedo. As such, a clear understanding and accurate characterization of vegetation dynamics is critical to understanding and modeling the broader climate system. Maximum tree height is an important feature of forest vegetation because it is directly related to the overall scale of many ecological and environmental quantities and is an important indicator for understanding several properties of plant communities, including total standing biomass and resource use. We present a model that predicts local maximal tree height across the entire continental United States, in good agreement with data. The model combines scaling laws, which encode the average, base-line behavior of many tree characteristics, with energy budgets constrained by local resource limitations, such as precipitation, temperature and solar radiation. In addition to predicting maximum tree height in an environment, our framework can be extended to predict how other tree traits, such as stomatal density, depend on these resource constraints. Furthermore, it offers predictions for the relationship between height and whole canopy albedo, which is important for understanding the Earth’s radiative budget, a critical component of the climate system. Because our model focuses on dominant features, which are represented by a small set of mechanisms, it can be easily integrated into more complicated ecological or climate models.
Here’s how the model and observations match:
Full paper: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0020551
h/t to WUWT reader “SandyInDerby”
The relationship between temperature can’t be linear since trees at some temperature trees diminish in size and don’t grow in the Arctic, Antarctic or at high elevations.
To begin with, it’s crazy to assume that ambient temperature affects predominantly the growth of plants.
/typo/
I think “The BCC story continues:” should read “The BBC story continues:”
Although maybe we could rename the BBC as BCC – any suggestions? 🙂
REPLY: Fixed, thanks -Anthony
BCC == Backers of Climate Change
I suggest it should say that the paper adds to the uncertainty of dendroCLIMATOLOGY not dendroCHRONOLOGY. The latter is a well established science that is not party to all the political controversies around the Hockey Stick etc.
REPLY: Point taken, change made – Anthony
Of course someone will want to say “Huh huh, Watts is dumb. This say tree height, not tree ring thickness like you lying d*****s say ‘hide the decline’ was about.”
Maybe they’ll figure out the unmentioned relationship, that for a given amount of growth (mass increase) a tree can grow short and stout or tall and skinny. If the tree opts to direct its growth to being taller than otherwise, then the rings will end up thinner than otherwise. Makes sense.
There seems to be something odd about these findings.
I started work in the timber industry, measuring, felling, milling, and observing. Almost any ‘U’ shaped valley with planted or natural trees across it has the tallest near the bottom, forming a shallower ‘U’ across their tops.
A long planted driveway to a house on high ground with planted trees either side of the drive will have the taller trees at the road junction.
I had assumed (dangerous I know) that it was deeper soil and more moisture that caused the difference. Now it seems that the higher temperatures at altitude cause this – – – – oh, that’s not right is it?
Why on earth would any sane person assume that just one parameter – temperature – effects not only the rate of growth of a tree but its rate of growth over its whole lifetime. One would expect it to be determined by competition with other trees and plants, amount of water in the soil, amount of nutrients, amount of CO2 in the air, amount of sunlight etc.
Trees grow at a wide range of temperatures succesfully – you can see conifers of all kinds from Turkey to Norway. You can see palm trees from Torquay to Tobago. Any gardener will tell you that what trees really need is lots of water. That’s what really constrains their growth. Competition with other trees for water as they all get bigger will also constrain their growth severely. So if you have a forest that burns down, then new trees sprout from the ashes more or less at the same time they will grow like crazy until they start competing with each other for water and other resources.
If you really want to use trees as a proxy for temperature I would suggest using tropical plants that can’t grow if there are winter frosts and measuring their geographic extent over time. This would be pretty definitive but one hell of a job to do.
I was under the impression that trees grow in relation to the available light. Probably why trees in forests can be at differing heights within the same species. A casual stroll through a rainforest will show giant hardwoods growing tall in a clear canopy area whilst their seedlings struggling to grow under a dense canopy area.
There are so many inputs driving tree growth that to have this leap of faith is the leap too far. But as BBC reported science it is perfect because it could then be concluded that trees need cooler climates so CO2 must be responsible.
What happened to the Seqoias, Firs and Sugar Pines of the Sierra-Cascades?
The observations look ultra-conservative to me.
JB Williamson
Ha! HA! BBC = BCC = Blind Carbon Copy…
Very good and so true.
(BCC to BBC)
John Tofflemire,
Or….in active volcanoes.
Bottom line , tree rings are only any good to tell you about the tree their taken form , as there are simply to many unknowns to justify their use for other things. The real problem is the lack of long term temperature information for which the ‘rings’ have been brought in to try and cover, but as most people know ‘correlation is not causation’ and to try and claim one factor ,while ignoring or not knowing all the others, is to blame is just plan stupid.
[ 🙂 ~ ctm]
Blind/bloomin’ climate catastrophists?
I think it would be a good idear to plant australian blue gums they love the heat and bush fires
It can certainly be said that it’s much worse than we thought.
The question is: “what is it, that is certainly worse than we thought”?
Is it the future prospects for the climate?
Or is just the quality of the climatic scientific research that is the problem?
“We present a model that predicts local maximal tree height across the entire continental United States, in good agreement with data”
——————————————————————————————–
What data?
Where did they find a 7 degree temperature change?………..
………..there’s not one
kadaka (KD Knoebel) says: “If the tree opts to direct its growth to being taller than otherwise, then the rings will end up thinner than otherwise.”
————————
The problem with your theorem is that are physical restrictions on how tall a tree can grow in relation to its girth. If a tree allocates insufficient girth to support its height, then wind (or even gravity) will snap it. A tree also has to be able to push water up to its top. The taller it gets, the fatter it has to get to do this.
“uncertain science of dendrochronology”
There is nothing uncertain about counting tree rings.
I think you are suffering from the American disease of semanicitis.
John Marshall says:
August 8, 2011 at 1:58 am
I was under the impression that trees grow in relation to the available light.
——————————
To illustrate your point, thirty years ago I cut off a 4″ diameter Red Gum sapling on the shady side of a group of 200 year old gums. It was ~35′ high and I wanted a bushy tree there so I cut it at eye level, knowing they bush out. It did, for a couple of years, then one branch took over and before long it was up to the canopy, about 45′, and now is about 6″ diameter at eye level, hardly a mark where it was cut and not a branch for 30′.
BCC = British Communist Central.
A few photos of trees in Australia.
As you can see they get bigger as the temperature decreases!!!!
What a ????? – Sorry can’t swear on this blog
A few images for perusal
http://cantwellcomputers.com/trees.html
Not sure how to use images on this blog
[You did just fine with the image link. ~dbs, mod.]
There are some interesting exchanges in the ‘climategate’ emails regarding the ‘uncertain science of dendrochronology’. For example, this one from David Schnare to Eugene Gordon on Sunday, 4th October, 2009.
===================================================
Humans tend to want to plant things that do not like the conditions they are in and must be nursed along to make any kind of showing at all. So, if I may disregard native trees at the moment, I can tell you assuredly, when it is cold my garden can hardly manage to get out of the ground, much less grow at all. When warm, my garden springs to life, weeds and all, and calls me daily to my weeding chore amongst the jungle of tall garden delights.
That said, we had a cold, wet Spring that caused all things to delay their Summer glory. When we finally did get some warmth, we found ourselves in the midst of a banner year for pasture grass. Good thing. We ain’t gettin no third cutting on Alfalfa this year. This sudden change happened in one season. Not two. We had prolonged wet, snowy cold, then we had late warm in one season. I can’t remember grass taller than this. So what caused it? The prolonged wet cold or the delayed warm?
What we can learn from Kempes et al:
1. This is real science which clearly shows that all work in paleo-climatology must be subjected to criticism on the basis of this science. (The real science part is that they are developing genuine physical hypotheses which can be used to explain and predict the behavior of various kinds of tree rings in various conditions.)
2. The data that support the Hockey Stick must be criticized anew on the basis of this work. (I have been screaming this for years. I cannot believe that it has taken this long for scientists to open the experimental side of paleo-climatology.)
3. Big parts of climate science are indeed experimental. (Why hasn’t this always been obvious? Have these people never seen an agricultural research station? Have they never seen a greenhouse?)
4. As Bomber_the_Cat shows above, through quotation, the IPCC was well informed that the claims of paleo-climatology were merely speculative. The IPCC suppressed this information.
5. Much of the work produced by Briffa and the others should never have been published and should never have received the blessing of a journal for the obvious reason that it was outrageously speculative.