How old was our eucalypt when it died in 2008?
Although frequently promoting trees as evidence of current climate change, it’s been my view for a while that the science of “dating” any specimen’s history via its growth rings, must account for extended droughts and abrupt climate disturbances such as flash flooding.
This example from yesterday’s street saga is no exception given the ACT region’s recent rainfall patterns.
I reckon our study in harsh climates also depends on the performance of particular roots over time.
Gavin.
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Looks like an ironbark.
Didn’t see previous story but have had many similar sized eucalypts expire for no apparent reason.
Its probably those rising sea levels Gavin!
Toby: Sea levels?
Good observation depends on your angle of approach and that includes the beach and any surrounding steps.
This bit of a stump can tell us a lot. For starters the kinky bit was on the SW side. If we were to examine several cores in the lab from say either side on the diagonal twenty past ten in the lower photo we should see a difference in growth rings and other dynamics. However the diagonal at six minutes past seven tells another story.
Do we average all four core samples?
Considering the tree as it was in real life I reckon one corner had deeper tap root than the others. Recall; most of this specimen was developing underground in its early years.
Urban trees and in particular street trees are particularly susceptible to stress, their roots are constrained and surrounding environment not conducive to proper growth. In the big storm in Sydney many trees came down, but few in the bush. Erratic watering and fertilising. Most councils regard trees as assets and have asset managers and they are now finding just how much it costs.
One factor which ensures eventual tree death – improper treatment at the seedling stage causing root girdling – failure can be 10, 20 or 30 years down the track.
Gavin I am at a loss as to what your message is. The age of a tree is the number of rings. The width of rings shows the amount of growth so a good year or bad. Are you asking how temperature is calculated? I live in Canberra as well, here I think the ages bandied about here about trees is nonsense. I have a very large tree out front that was planted in 1974. It would be 80-90cm I have seen here claims that such a tree would be more than 350 years old.
Eucalyptus can grow very fast but the opposite is also true. Depends on seasons and soil. Not so much temperature.
A magnificent Sydney Bluegum [E. saligna] was recently cut down in our shopping centre with a diameter of 3 METRES!! It was a healthy tree.
An absolute Australian icon. The stump grinder could hardly handle the job.
Don’t it always seem to go!
DHMO: “The age of a tree is the number of rings”
Are you sure about that? I’m considering with the above sample, E. nicholii how hard it was to see continuous rings across the slice. Btw; there was no time to smooth and polish a piece before it all disappeared.
Tree rings as a temperature gauge? Certainly not for your average scientist with solar energy, shade, rainfall and nutrient competitions varying all over the place.
“Dendroclimatology is a young science—improvements in methods are being made to squeeze the most insight from tree ring evidence. While the number of factors affecting growth of a tree ring may seem daunting, there is still much good information tied up in tree ring records. Current inferences from tree rings (even if imperfect) are better than knowing nothing about previous climate”
http://en.wikipedia.org/wiki/Dendroclimatology#Non-linear_effects
Matthew Brookhouse ANU 2006
“Dendrochronology has the capacity to provide unique insights into natural vegetation dynamics and yield climatological reconstructions. However, because of a persistent belief that eucalypts are unsuited to dendrochronological analysis, research interest in the genus has been limited. A thorough review of the eucalypt dendrochronological literature reveals that perceived limitations may be locally overcome. However, methodological problems associated with many studies mean that results are often difficult to interpret. Consequently, the dendrochronological potential of the eucalypts remains unresolved. To overcome this, a detailed dendrochronological reconnaissance of the eucalypts, drawing on established datasets, systematic study of individual species and sites and examination of non-width-based tree-ring properties, is recommended”
http://www.publish.csiro.au/paper/BT05039.htm
See also
fennerschool.anu.edu.au/news_events/seminars/brookhouse_dec2007.php
Trees of great bulk and age once grew in my home state Tasmania. Although the unique “pines” growing in wild places there have been the subject of considerable blog science since the warming thing I doubt if even a few have a handle on the issues there.
Old trees tend to grow in difficult places and are often anything but symmetrical. Great burls are common and these pieces may survive longer on the ancient forest floor as they do on old stumps and trunks. A combination of deformities can cause false rings. These are easily recognised by timber workers.
My dad had a universal word for all such bizarre growth, he called it “cranky” grained timber and we burned much of it as domestic firewood when it failed to machine easily.
Ignoring the John Daly links we can find a little genuine research on these matters.
http://www.cmar.csiro.au/e-print/open/francey_1984a.pdf
This region is where my folks lived and worked for generations. We saw a lot of very old forests changing into timber.
So you are talking about temperature. I may stand corrected but yes I do think it is one a year even though very difficult to read. On the climate audit site they tried to revisit Mann’s bristle cone study. There is quite a bit of technical stuff there on how to read the rings. I have read some about past climate and tree rings they ought to be able to give some idea of temperature but we will need a mountain. They have tree lines. You look at the trees on the edge now. If the trees are younger than those lower down then it’s getting hotter we are all doomed! If you find older dead or dieing then it was hotter in the past and it’s getting colder, we are all doomed! Frankly I don’t think this could be at all certain since all living things adapt and there has to all sorts of factors. Finally to get accuracies of a tenth of degree from this seems impossible, maybe there really are fairies at the bottom of the garden.
Gavin,
Eucalypts are notoriously difficult to perform dendrochonological analysis on. One reason is that they are a very advantitous species, i.e. they will grow when conditions are good and reduce growth when they are poor, not necessarily following an anual cycle such as northern hemisphere trees are known for.
Eucalypts will also respond to different factors but water availability is most likely the main factor for growth as eucalypts are notoriously poor regulators of their water use, especially iconic species such as E.regnans. Given sufficient water then other factors will come into play. Beyond water availability is becomes difficult to glean any climate related information from them. Perhaps the work being carried out by Matt Brookhouse, as noted in your post above, will shed more light on this over the next years.
As for your street tree, it is not just climate that determines the growth performance of trees. Roads, footpaths, access to water, nutrient availability, compaction etc all have a role in the growth and survival of street trees.
So you are talking about temperature. I may stand corrected but yes I do think it is one a year even though very difficult to read. On the climate audit site they tried to revisit Mann’s bristle cone study. There is quite a bit of technical stuff there on how to read the rings. I have read some about past climate and tree rings they ought to be able to give some idea of temperature but we will need a mountain. They have tree lines. You look at the trees on the edge now. If the trees are younger than those lower down then it’s getting hotter we are all doomed! If you find older dead or dieing then it was hotter in the past and it’s getting colder, we are all doomed! Frankly I don’t think this could be at all certain since all living things adapt and there has to all sorts of factors. Finally to get accuracies of a tenth of degree from this seems impossible, maybe there really are fairies at the bottom of the garden.
DHMO: “I have read some about past climate and tree rings they ought to be able to give some idea of temperature but we will need a mountain. They have tree lines”
Tree lines can be studied at various altitudes and latitudes. With our eucalypts I have been particularly interested in the extremes, at sea level and the snow line. One question I have looked at is where eucalypts occur on sand dunes of recent geological time
“Frankly I don’t think this could be at all certain since all living things adapt and there has to all sorts of factors”.
Rate of change is a factor, red gum forests denied natural flooding don’t last forever.
“Finally to get accuracies of a tenth of degree from this seems impossible, maybe there really are fairies at the bottom of the garden”.
I think we need to have another look at how a modern instrument record can give us parts of a degree C over time.
Pandanus67 is right is saying mountain ash, E. regnans depends greatly on a high average rainfall.
In the adaptability stakes alpine ash E. delegatensis or the stringy bark E. oblique are likely better choices for out climate studies however I’m going to suggest again the snow gum E. Pauciflora is the ideal signature species for temperature change across southern Australia.
Gavin would there be anywhere in Australia high enough with suitable trees to indicate much at all?
DMHO: With appropriate funding and eyes wide open I believe we can learn something from a wide range of long lived tree species, sub species and their locations.
Before seeking help from google again I thought about previous discussions regarding ancient trees on Mt Read at 1000 m in Tasmania’s western snow line, also the limits of glaciers and permanent ice caps in the same region. I recalled also a large eucalypt growing in between the dunes at Lake Pedder then started wondering about tales of giants, E. rubida (candlebark) in the Mt Lofty Ranges beyond Adelaide.
“A BLUEGUM tree flourishing in South Australia could be up to 2,000 years old, scientists believe”
http://www.theaustralian.news.com.au/story/0,,23597300-30417,00.html?from=public_rss
Avoiding the obvious, blue gums E. globulus seemed too easy. Tough!
I have always known even dead trees tell tales but we must first understand their habits to see through any remaining bulk and buried debris. Understanding stumps and logs is as much the key to ancient forests as any other numerical method.
“FEATURE ARTICLE: HOW DO WE KNOW ABOUT CLIMATE IN THE PERIOD BEFORE INSTRUMENTS?”
“The best single proxy temperature record from the Australian region is the record of tree rings from Huon pines on Mount Read in western Tasmania. This extends back to 1600 BC. It suggests that multi-decade means of temperature in the second half of the 20th century were the highest of the last 3,600 years, but not by a large margin, with temperatures almost as high being sustained over a much longer period at various times between 900 and 1500 AD. (It should be noted that this data set ends in 1992 and instrumental data indicate further warming since.) The data also suggest that the early part of the 20th century was rather cold by the standards of the last 3,600 years. There are only modest (typically less than 0.3°C) variations in multi-century means of temperature over the 3,600-year period, but an interesting feature is that the level of interdecadal variability of temperature between 1500 and 1900 was substantially lower than that prior to 1500, and particularly prior to 100 AD”.
http://www.abs.gov.au/AUSSTATS/abs@.nsf/Latestproducts/1301.0Feature%20Article1012008?opendocument&tabname=Summary&prodno=1301.0&issue=2008&num=&view=
tree photos
http://www.news.com.au/adelaidenow/story/0,22606,23599235-2682,00.html
http://www.forestrytas.com.au/news/2007/11/650-year-old-huon-pine-discovered-on-river-bank
hi im jay im a yr 9 student from nyanda high and for our science class we are looking at the effects on climate change, we also have to write a 2 page sa. i have choosen tree rings and i find this page very interesting so thank you very much for your help