Big Trees: a new look at growth factors

Big_Tree_400x400Guest Essay by Kip Hansen

Last week I had the opportunity to attend a presentation by Dr. Seth Bigelow, previously of the US Forest Service and currently doing original Forest Adaptation Research at the Huyck Biological Research Station near Rensselaerville, New York (about 20 miles southwest of Albany). Dr. Bigelow has been conducting such research for 20 years.

Bigelow’s presentation focused on the results of his latest paper published in March 2014 in the journal Climatic Change entitled: “Faster growth in warmer winters for large trees in a Mediterranean-climate ecosystem” (journal article paywalled but a free full .pdf is available here).

The study, which took place in Plumas County, California, in the conifer-covered mountains at the junction of the northern Sierra Nevada and the southwestern end of the Cascade Mountain ranges, “analyzed growth rings of five conifer species against 20th century climate trends from local weather stations” in order to predict the “likely performance of large trees [those having breast-height diameter >76 cm / ~ 30 in] in a rapidly changing climate.” This is a question of high interest because of the generally accepted view that:

Large trees are an iconic and functionally irreplaceable element of the lower montane mixed-conifer forest, and the steady rise in surface temperature in California throughout the 20th century has rightfully engendered concern about their performance, raising the specter of a positive feedback loop in which elevated temperatures due to anthropogenic carbon emissions inhibit the ability of trees to take up carbon.

This climate change worry seems to have been put to rest by this study – at least for the large conifers studied at this location – in which the authors state that “Our findings may help to allay such fears as regards large trees.” The authors conclude that:

Minimum winter temperatures have been a major determinant of growth of large trees in the lower montane mixed-conifer forest in northern California over the 20th century, eclipsing even precipitation in importance. The five species studied show increased growth with higher minimum winter temperatures, a pattern that was stronger and more prevalent than decreasing growth with higher summer maximum temperatures.”

This study that shows, as with temperature-related human mortality, that the lowest temperatures may be more of a determining factor of biological success or failure than highest temperatures, at least in the temperature ranges experienced today.

# # # # #

Note: Dr. Bigelow’s current study, using tree rings and tree neighborhoods to understand growth in a changing climate in sugar maple, yellow birch and hemlock, is ongoing this summer at the Huyck Preserve Biological Field Station near Rensselaerville, NY. Dr. Bigelow welcomes volunteers. Contact the Huyck Preserve at 518-797-3400.

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55 thoughts on “Big Trees: a new look at growth factors

  1. Millar et al. looked at trees killed on Whitewing Mountain in the Sierra Nevada by a volcanic explosion in 1350. They concluded that between the years 815–1350 the climate was some 3°C warmer and slightly drier.

    They write “The modeled Whitewing Medieval climate closely compares to climate projections for California in AD 2070–2099….Recognizing significant CO2 differences between future projected and Medieval climates, our empirical findings of significant increase in subalpine forest extent and diversity during similar climate conditions nonetheless raise questions about modeled results of future forest reductions in the subalpine zone.”

    Late Holocene forest dynamics, volcanism, and climate change at Whitewing Mountain and San Joaquin Ridge, Mono County, Sierra Nevada, CA, USA

    http://www.fs.fed.us/psw/publications/millar/psw_2006_millar027.pdf

  2. ” raising the specter of a positive feedback loop in which elevated temperatures due to anthropogenic carbon emissions inhibit the ability of trees to take up carbon.”

    I read a paper, maybe 5-8 years ago, on the California land based temperature record. When the authors removed all the badly sited stations, they found no trend in CA temperatures for the past several decades. That is, there was no instrumental evidence of warming in California.

    I can’t find this article now. Can anybody help?

  3. Not a bristlecone pine in sight. And no reference in the bibliography to Michael Mann. I wonder why?

  4. “nickreality65 says:
    July 6, 2014 at 6:25 am

    “…breast-height…” Is that a metric or English breast? Before or after three children and 40 years of gravity?”

    That’s a standard lumber industry way of measuring a tree…

  5. “Our findings may help to allay such fears”
    I doubt it; they’re afflicted with the disease:

    I applaud the effort to insert calm rational evidence based science into the alarm machine though.

  6. The five species studied show increased growth with higher minimum winter temperatures
    ——————–

    If one has …. “higher minimum winter temperatures” …… does not earlier spring temperatures follow?

    The quicker the ground warms up, ….. the quicker you can plant your potatoes.

  7. These are lovely areas to hike, and that Whitewing paper ^^^is very interesting. Roughly 3.5 degrees warmer during the MWP?

    Most of these trees are in very dry areas. I’d expect water stress (especially in late summer) might have more to do with growing seasons than minimum temperatures, but I ought to read the papers more carefully before saying that. But I’ve hiked some of these areas in August, and the mountain tops above the treeline are very dry & rocky. During the winter they are covered in snow (e.g. dry) and then by the end of the summer they are also dry. As usual, I have trouble seeing how to separate the temperature from the moisture component of historical tree studies…

  8. p.s. Higher minimum winter temperature may actually be a proxy for winter water availability. When you ski these areas, you notice that even in areas with deep powder, there is a marked tendency around the base of these big evergreen trees to have what looks like melted snow at the base near the bark. I can’t help but wonder whether reflected sunlight is melting some of the snow right around the tree resulting in slightly more water flowing down to the roots during warmer winters. Freshly fallen snow frequently piles up near the trees, but after a few weeks of sun, you’ll see a gap between the snow and the bark leading down, sometimes though several feet of snow.

  9. Nickreality65 inquires: ““…breast-height…” Is that a metric or English breast? Before or after three children and 40 years of gravity?”

    Strangely enough, there is indeed an English breast height — 4.5′ (1.37m) and two metric breast heights (1.3m and 1.4m). As in many cases, the standard isn’t standard.

    Ref: Wikipedia: http://en.wikipedia.org/wiki/Diameter_at_breast_height

  10. joel says:
    July 6, 2014 at 5:38 am

    I read a paper, maybe 5-8 years ago, on the California land based temperature record. When the authors removed all the badly sited stations, they found no trend in CA temperatures for the past several decades. That is, there was no instrumental evidence of warming in California.

    I can’t find this article now. Can anybody help?

    There is a short comment by Jim Goodridge in 1996 that help turn our host into a skeptic, see

    http://wattsupwiththat.com/2010/01/31/uhi-is-alive-and-well/

    It features a graphic showing very little warming in low population counties and much greater warming in high population counties.

    Digging up something involving weather stations will take more time than I have, was it a spinoff of the SurfaceStations project?

  11. I am pleased to see this paper uploaded since it is relevant to the article by Willis onThe Revenge of the Climate Raparations.

    In that article, I have made a couple of comments regarding what I see as a ‘false’ accounting scam that governments are using to close down coal powered generators in favour of biomass powered generators. See my posts at July 5, 2014 at 9:16 pm and at July 6, 2014 at 8:23 am (which is awaiting moderation).

    We are told that biomass is carbon neutral in the sense that the CO2 that is emitted when biomass is burnt is offset by the CO2 that they absorbed during the lifetime of the trees. However, that reasoning is false since the position is either

    1. We are cutting down virgin forest to be used for biomass and that virgin forest is not being replanted, or
    2 we are cutting down a forest which is an existing carbon sink and would continue to act as a carbon sink if it were not cut down. If we cut down that forest and replant, all we are doing is replacing an existing carbon sink with the ‘exact’ same sink, so we are not thereby taking out any additional CO2. On a global basis nothing has changed and we are in the same position that would be the case if we never cut down the trees.

    Burning biomass produces more CO2 than does burning coal or gas (it has a far lower calorific value and per tonne produces considerably less energy). Since biomass creates more CO2 emissions, if you desire to reduce global CO2 emissions you need to add an additional carbon sink. Replacing an existing sink with the ‘exact’ same sink does not achieve that result.

    In my earlier post (July 5, 2014 at 9:16 pm on the Willis article), I stated that I thought the ‘false’ accounting was based upon the assumption that new young trees absorb more CO2 than old trees, such that replacing old trees with young trees absorbs more CO2. I could never see why that assumption was being made given the volume of a cylinder (compare growth of a large tree with that of a young tree) and the canopy of a large tree is much larger than that of a young tree so large trees have more leaves (or needles).

    This paper shows the error in that assumption. Old trees are just as efficient at removing CO2 as young trees. There is no gain in CO2 sink in cutting down an old forest and replacing it with a young forest.

    This paper therefore confirms why the switch to biomass is madness.

  12. Moderators

    My last 2 posts (one on this thread and the other on The Revenge of the Climate Raparations) are awaiting moderation. I can see no reason why that should be the case. I would much appreciate you advising why my posts are caught up so that I can amend my style or content to avoid that happening.

    As I say, I consider my last 2 posts to be inoffensive and uncontroversial, so I can see no reason why they should be dragged into the net.

    Your explanation would be much appreciated.

    Thanks and kind regards
    Richard Verney

  13. Wow! Just Wow! During the first part of the Carboniferous Period during the Devonian had average temps around 68 degrees (F) with CO2 at around 1500 ppm. Then somewhere around the mid-point of the period, the Earth cooled to around 55 degree (F) with CO2 around 350 ppm.

    The Carboniferous Period produced all that balck coal from plants the Greenies don’t want to recycle into more plants. Oh, and the Jurassic Period had around 1800 ppm. We’re actually starving our tomatoes today and, if Greens have their way, will kill them along with those the trees they hug so much.

    One can deduce the Greens and our esteemed tree folks just don’t want the Earth never make coal again.

  14. “The strong coherent response to increasing minimum temperatures bodes well for growth of large trees in Sierra/Cascades region mixed conifer forest under continued climatic warming, but these trees will still be under threat by the increased fire intensity that is a indirect effect of warming.”
    Yes, of course. Even though any observed increase in fire intensity probably has more to do with poor forestry practices and fire supression, leaving more available dead wood available as fuel. But yeah, in the future it will happen, because the CO2 climate wizards know all, and can see all.

  15. richard verney says:
    July 6, 2014 at 8:55 am
    Moderators

    My last 2 posts (one on this thread and the other on The Revenge of the Climate Raparations) are awaiting moderation. I can see no reason why that should be the case. I would much appreciate you advising why my posts are caught up so that I can amend my style or content to avoid that happening.

    The one in this thread contains the word “madness,” which might have got caught in the filter. (I’ll know when I hit the button on this comment.)

  16. but tree rings
    but a hoaxed temperature series.
    but the pause.

    funny how we forget things when we like the answer

    Reply: and funny how you insert the word hoax regarding temperature series when I don’t recall having ever published anything here saying that was a hoax.

    Not helpful.

    My position has been and always has been that the temperature record is over adjusted and does not deal with long period Signals such as UHI and station encroachment very well. Anthony

  17. oh my

    “Monthly precipitation and minimum and maximum temperature data were obtained from
    four weather stations within the sampled area (Fig. 1; URL: http://www.wrcc.dri.edu). Precipitation
    data were averaged at monthly intervals then summed based on a hydrologic year beginning in
    November. Temperature data were gap-filled, averaged at monthly intervals, extrapolated to
    1,400 m elevation based on l”

    they filled gaps and extroplated.. thats not real data, thats adjusted, made up, data

    /snide off
    /sarc off

    One of the reasons folks like NOAA create in filled, adjusted data series, one of the reasons folks
    extrapolate and interpolate is Other science ( like this study) need the best estimate of data in places
    where you dont have a station. So, for example, the forest management guys use this kind of data
    when they dont have a thermometer exactly where they need one.

    They have a practical need and this data fulfills that use.

    • Yes but when you have eight thousand thermometers and Gavin says 50 or so will do what’s the point in doing all this extrapolation?

  18. cedarhillr says:
    July 6, 2014 at 9:03 am

    Do you mean “and during the Devonian”, which Period preceded the Carboniferous? CO2 fell during the Devonian, perhaps thanks to the spread of land plants, which responded to the drop by evolving more stomata, offering a selective advantage to large laminate leaves. Its level declined even more during the Carboniferous. At the same time, O2 increased. In the Late Devonian, the first semi-terrestrial vertebrates (tetrapods) evolved from lobe-finned fish, then developed shelled eggs in the Early Carboniferous, freeing our ancestors from the need for water to reproduce.

  19. Reply to Indur Goklany: Comparing across the 20th Century for CO2 induced growth should then have presented general increasing growth pattern similar to CO2 atmosphereic concentrations for them same period. This is not what Bigelow found.

    Reply to joel: Dr. Bigelow co/mpares tree growth rings with reports from four local weather stations. “Monthly precipitation and minimum and maximum temperature data were obtained from four weather stations within the sampled area. Precipitation data were averaged at monthly intervals then summed based on a hydrologic year beginning in November. Temperature data were gap-filled, averaged at monthly intervals, extrapolated to 1,400 m elevation based on locally computed lapse rates, and averaged by season”. Thus, the data that there has been “no trend in CA temperatures for the past several decades” is irrelevant to this study.

    Reply to nickreality65: “Breast-height” is an generic measurement used in the timber industry and amongst arborists. Thanks to the several readers [mjc, and others] who answered this for nick.

    Reply to John West: Science advances by this mechanism: a common “everybody knows that…” is investigated scientifically someone like Dr. Bigelow and found to be false. Rather, the scientist finds that something else is the case. Knowledge is now advanced “uno pocito” — fake latin for a little bit.

    Reply to Samuel C Cogar: Your question “If one has “higher minimum winter temperatures” …… does not earlier spring temperatures follow?” Early springs are not directly related to “minimum winter temperatures”. In layman’s terms, we might call a winter with a “higher minimum winter temperature” a MILD winter, and a winter with a very low minimum temperature a HARD winter, neither of these relate to the length of winter, or the arrival of the melt and growth seasons. Here in NY State, we can have short, hard winters, or long mild winters, or any combination of hard/mild and short/long (along with al the other variables — snowy, rainy, dry, etc).

    Reply to Ashby: “As usual, I have trouble seeing how to separate the temperature from the moisture component of historical tree studies…” Read Dr. Bigelow’s study at http://www.forestadapt.org/bigelowpapaikcaumnorth.pdf It is only 11 pages, and quite informative.

  20. Reply to Bruce Cobb: re: “trees will still be under threat by the increased fire intensity that is a indirect effect of warming.” You are right, of course, Bigelow states in his conclusion: “Vigilant forest management will nonetheless be required to protect and recruit large trees, which despite their exceptional fire resistance are still vulnerable to the increasingly large, intense, and frequent fires characteristic of present-day western conifer forests.” Included in this statement is the fact of the negative results of a long-term fire-suppression regime in the region.

    Reply to Steven Mosher: Read closer — and more accurately. This is a study of tree growth as indicated by tree rings compared against three local measured climatic factors — taking data from the raw records of four local weather stations. It is a million intellectual miles away from trying the reverse — turning trees ring records into a thermometer.

    Please try to keep your criticisms germane to the topic at hand. If you have issues with the use of proxies of various types, management and adjustment of climatic records and use of historical climate data with the host of this blog (or any other individual, other than my self), please take it up with them by private email. Otherwise, you are just “mouthing-off” — like a bully on the schoolyard.

  21. Well this little write up could end up costing him plenty.
    His job, his career, his savings, his home, his family hell, his whole future gone in a flash.
    Did he not check with Mikey? Whoa, and no hat tip to CAGW, that’s ballsey.
    How’d this get through, anyway?
    cn

  22. I may have spoken too fast.
    It was a weak statement but maybe the closing sentence helped him.
    cn

  23. Reply to Chuck Nolan: Dr. Bigelow is not crazy — he got in the required AGW/CAGW kowtows — he just didn’t allow the “consensus view” to alter his findings.

  24. joel says:
    July 6, 2014 at 5:38 am

    I read a paper, maybe 5-8 years ago, on the California land based temperature record. When the authors removed all the badly sited stations, they found no trend in CA temperatures for the past several decades. That is, there was no instrumental evidence of warming in California.

    I can’t find this article now. Can anybody help?

    from: http://www.sustainableoregon.com/goodridge.html

    http://wattsupwiththat.com/2012/08/16/never-before-published-paper-on-uhi-and-siting-goodridge-1987/

    http://wattsupwiththat.files.wordpress.com/2012/08/goodridge_1987_paper.pdf

    thanks
    JK

  25. There are “lumpers” and “splitters.” This article is a small area with limited, if any, application elsewhere. Most of the comments seemed inclined to further split the argument. Not incorrect per se, but of limited interest IMHO.

  26. Kip Hansen says:
    July 6, 2014 at 2:04 pm
    Reply to Steven Mosher:
    Please try to keep your criticisms germane to the topic at hand…….Otherwise, you are just “mouthing-off” — like a bully on the schoolyard.

    Kip,
    Perfect! Just… Perfect.
    Mac

  27. Reply to inMAGICn ==> Yes, thus reported in <500 words. "This article is a small area with limited… application …." Dispelling false assumptions, like "raising the specter of a positive feedback loop in which elevated temperatures due to anthropogenic carbon emissions inhibit the ability of trees to take up carbon” is the tedious work of dedicated scientists who carefully study the subject, in one carefully controlled experiment/study at a time. That is how real science advances.

    It is uncharitable to say "But this study covers only a small area…" — there is no other way to do this science right. He staked out a geographical area, with a carefully conceived parameters, to find the apparent truth [whatever is to be found] about this one question. His conclusions are properly limited to his exact findings.

    Real science seldom consists of a big "Ah-Ha — Eureka!" finding — the studies that claim such are usually being stretched far beyond their proper bonds.

    Personally, I prefer small, careful, well-done studies, rock solid in their limited findings.

  28. Seems like people commenting here do not live in the north, and do not know that snow in an insulator. My grandmas home in northern Vermont (about 10 miles from Canada, had running spring water year round. She had no well and that was her sole source of water. The water came from the spring head more than 500 wards from the cabin. The lead pipe (didn’t have plastic pipe in the early 1900’s) was only about a foot under ground. Seems like there is this unknown natural phenomenon where after there is about a foot of snow, the snow acts like an insulator and allows the heat from the earth to keep the pipe from freezing. So I would surmise that the snow surrounding the trees in the article MELTED, provided the trees with water. Six feet of snow is a probably better then the 15 inches of fiberglass in your attic. And, by the way, Grandma lived to be over a hundred years old, Gramps was in his 90’s, drinking water from that “lead pipe.”

  29. Reply to usurbrain ==> The soil under your six feet of snow is generally frozen solid to a depth of at least two feet — more if there was extreme cold before the snow fell. In the mid-Hudson Valley of NY, water supply pipes are required by code to be covered with at least 3 feet of soil to ensure that they remain unfrozen.

    As for your grandmother’s spring water — moving water in a pipe can remain unfrozen as water at > 32º F moving through the pipe keeps it open — even just a tiny flow is often effective — thus it is the pipe of ‘warmer’ water that keeps the earth around the pipe unfrozen. Don’t take my word for it, next winter, say New Years Day, go out, scrape away the snow and try to dig a hole for your live Christmas Tree.

    We lived in a house along the Mohawk River with a similar water supply, cistern in the basement.

    The snow insulates the ground from temperatures COLDER than freezing — thus snow caves are effective shelter for snow-bound hikers.

    In any case, for trees, it is my understanding that photosynthesis is greatly reduced at winter temperatures — thus even evergreen trees in winter areas mostly ‘shut down’ for the winter.

  30. Kip,

    I am familiar with the methodology. And I am hardly claiming that we need grand ah-ha moments. As a matter of history, plate tectonics required a slew of smaller observations to come up with the grand theory. My point was, if inadequately explained, that people tend to glom onto the results of such studies and use improper logical induction as evidence of global or large scale interpretations in general. I merely think this study was so limited it has limited application. As an earth scientist, I may be missing the relevance of the study on climatology in the argumentation offered in the postings.
    Thank you.

  31. Precipitation level, warmer more rain. Conifers pine etc., go dormant in winter. Very little growth is achieved, the same with deciduous trees.

  32. usurbrain says:
    July 6, 2014 at 7:07 pm

    “… The lead pipe (didn’t have plastic pipe in the early 1900′s) was only about a foot under ground…. Gramps was in his 90′s, drinking water from that “lead pipe.”
    //////////////////

    Most natural water has salts in it. These deposit on the inner wall of the pipe, forming an encrusted barrier (which to running and free flowing water is for all intents and purposes impermeable). As a consquence, the lead is only in contact with the water for a relatively short period of time as the hardened crystaline layer builds up. Say for a year or so. Once this crystaline crust has build up, there is no issue.

    This is why lead plumbing was never a serios problem, The issue became an issue, because the ‘experts’ failed to consider real life conditions in which the plumbing is used, distinct from laboratory experimental data on the properties of lead.

    I guess that there may be some similarity with CO2. An over emphasis on the laboratory properties of CO2, without understanding how it behaves in the real world conditions of planet Earth’s atmosphere..

  33. richard verney says:
    July 6, 2014 at 8:51 am

    2 we are cutting down a forest which is an existing carbon sink and would continue to act as a carbon sink if it were not cut down. If we cut down that forest and replant, all we are doing is replacing an existing carbon sink with the ‘exact’ same sink, so we are not thereby taking out any additional CO2. On a global basis nothing has changed and we are in the same position that would be the case if we never cut down the trees.
    ———————-

    There is a vast existing carbon sink that is the result of past forests being cut down. Billions of tons of sequestered carbon.

    A vast existing carbon sink that one very seldom if ever hears/reads mention of.

    And part of that vast carbon sink dates back to the 1800’s and consists of houses, barns, buildings, factories, warehouses, railroad infrastructure, commercial infrastructure, boats, furniture, etc., etc., and other wood products.

    The Chicago Fire and the San Fran earthquake returned a lot of that carbon back to the environment.

  34. Kip Hansen says:
    July 6, 2014 at 1:39 pm

    Reply to Samuel C Cogar: Your question “If one has “higher minimum winter temperatures” …… does not earlier spring temperatures follow?” Early springs are not directly related to “minimum winter temperatures”. In layman’s terms, we might call a winter with a “higher minimum winter temperature” a MILD winter, and a winter with a very low minimum temperature a HARD winter, neither of these relate to the length of winter, or the arrival of the melt and growth seasons. Here in NY State, we can have short, hard winters, or long mild winters, or any combination of hard/mild and short/long (along with al the other variables — snowy, rainy, dry, etc).
    —————–

    Kip, thanks for your response and I apologize for not specifically stating so but I was referring to both air and soil temperatures, thus my “planting potatoes” reference. And thanks for the “layman’s” terminology … but I’m far from being a layman on the subject.

    And I disagree with you about the HARD verses MILD winter relative to the spring melt and the start of the growth season when you claim “neither of these relate to”. They don’t relate to the “length of winter” if you are referring to the “equinox winter”, …. but they do if you are referring to the air temperatures and those other variables you mentioned. Less snow pack and/or less frozen ground depth mean a MILD winter … which usually means a quicker “warm-up” and melting after the spring equinox and an earlier start of the “growing” season. (A lot of rocks [solar heat sinks] in your garden also hurries up the spring growing.)

    Here in West Virginia during the 20+ years when I was growing up the winters were “long n’ FIRM”, but now days we have had MILD winters for the past 20 years or so. But between 1966 and 1980, or thereabouts, I lived in Herkimer County, NYS, near Utica, and every winter was “long and HARD” with heavy snow fall/snow pack and below ZERO F temperatures. (Except for those January “thaws”)
    When one of one’s hobbies usta be raising beef cattle then one pays close attention to the weather.

    “A cold, wet May will fill the barn full of hay”, …… ya know.

  35. usurbrain says:
    July 6, 2014 at 7:07 pm

    —- the snow acts like an insulator and allows the heat from the earth to keep the pipe from freezing. So I would surmise that the snow surrounding the trees in the article MELTED, provided the trees with water.
    —————-

    Snow is an insulator. And covering a waterline lying on top of the ground with Spruce or Pine branches will prevent the water from freezing as long as the water is flowing thru the pipe. And the snowmelt around the tree trunks is a result of solar energy absorption by the “dark” colored tree bark. And trees don’t need any water until their Spring growth begins.
    ==============

    Kip Hansen says:
    July 6, 2014 at 7:58 pm

    Reply to usurbrain ==> The soil under your six feet of snow is generally frozen solid to a depth of at least two feet
    ————

    NAH, that will only occur IF there was extreme cold for a week or two before the 1st snow fell.

    Just ask any ole Field Mouse or Ground Mole or Vole and they will tell you all about it.

  36. Reply to Samuel C Cogar ==> Your garden must be different than mine.

    Question to Readers: What are your experiences with soil under snow in winter in the northern latitudes?

  37. Reply to Samuel C Cogar ==> What’a’ya’know! I lived along the Mohawk in St Johnsville, for a number of years.

    I’ll leave it up to you to research the data (for any particular locality) that shows Minimum Winter Temperature directly affects season length. [I am pretty sure that you will find that there can be really cold "cold snaps" in short winters, and 'not so cold' in winters that linger longer.]

  38. Samuel C Cogar says: @ July 7, 2014 at 10:29 am I will agree with that.
    Here is one set of freeze depth data. It shows about a foot average for VT. http://www.fhwa.dot.gov/publications/research/infrastructure/pavements/ltpp/08057/07.cfm
    Others are available.
    @ Kip – Try digging that hole after there has been 3-4 feet of fluffy snow for several months on top of the place you dig and around it for several hundred yards (a plowed road/driveway will affect the freeze area/depth.) That along with the blanket of fallen grass/weeds/branches between the soil and snow cover makes it quite manageable. I never had any trouble in VT. However, with less than a few feet of snow there will be problems. Happened in VT several years back when there was very little snowfall – and many homes had frozen water pipes. I think northern VT gets more snow than the middle of NY – Further north and higher elevation, and decreases the frost depth.

  39. Kip Hansen says: July 6, 2014 at 7:58 pm “In any case, for trees, it is my understanding that photosynthesis is greatly reduced at winter temperatures — thus even evergreen trees in winter areas mostly ‘shut down’ for the winter.”
    Many years ago I lost a beautiful Hemlock. The local AG Ext. told me I should have watered it every few weeks in the winter or put a “sealer” on the needles. Since then I have watered all of my decorative evergreens and the trees that have not matured. Last winter was quite dry in this part of NE, only got a few inches of snow, and several of my neighbors Ewes and other evergreens. In fact there were dead evergreens all over town. I did not lose any and, unlike the neighbors, all had good healthy new growth this spring. Why do mine grow faster/fuller than the neighbors? Why did mine survive and not the neighbors on either side of me? Was it pure luck? Was I wasting water?

  40. Reply to usurbrain ==> The linked chart you supplied answers all the questions about expected, historic, average, freeze-line depths, across three seasons, for all 50 States. Anyone with questions about this can just check there, it is excellent.

    I agree with your Extension Agent — evergreens can “dry out” under certain conditions — particularly when the air is warm (opening pores in the needles allowing them to transpire) but the ground is still frozen around the roots, not allowing them to take up water. New plantings with shallow root systems are at greatest risk, as I understand it. Thus, the advice you received. The leaf/needle sealer is the most effective, watering alone can help especially if evergreens are next to your house foundation, where the freeze/thaw cycle is slightly different.

  41. Kip Hansen, on July 6, 2014 at 1:39 pm — I didn’t claim that the increasing growth pattern should have been similar to CO2 atmospheric concentrations for the same period. What I said was that they apparently “forgot to check whether increasing CO2 levels had any thing to do with plant growth.” Tables 2 and 3 which indicate their regression results doesn’t list CO2 as a dependent variable.

  42. Reply to Indur Goklany ==> I am not sure why you would want them to check CO2 concentrations as an independent variable. I am willing to hear your reasoning, but in my mind, having attending Dr. Bigelow’s lecture and read his paper, this would not have added anything to the study. Local weather stations do not/did not measure atmospheric CO2. Thus, Bigelow would have had to depend on vaguely applicable measurements from Mauna Loa — which you probably know show a pretty steady increase over the period covered by Bigelow’s study, all in one direction (increasing concentrations). On a practical level, the changes Bigelow is looking for are seasonal/year-to-year, so a fairly steady change over the long term would not have affected the types of changes he is looking for. The very small differences in concentrations, one year to the next, or inter-seasonal, are very small and have little or no effect — especially given that there are no local measurements.

    Glad to hear your view if different.

  43. Kip Hansen says:
    July 7, 2014 at 11:08 am

    Question to Readers: What are your experiences with soil under snow in winter in the northern latitudes?
    —————–

    When living upstate NY, one of my sad experiences was, to wit:

    One spring I planted 10,000 Pine seedlings …. with at least 5,000 of them in 4 staggered rows along the sides of my driveway/road to my house for the purpose of a “snow fence”. They were like 8” to 10” seedlings and 99% survived that first summer …… and they also survived the 2’ to 4’ of snow that covered them that winter. And they grew n’ survived the next 2 summers n’ winters and were then like 20” to 24” tall.

    But the 4th winter of their young life started out “blue cold” …… and no snow ….. and the ground froze solid down to 12+ inches. And then we got the snow and it covered all my Pine trees up, …. not to be seen again until Spring. By mid to late February the “snowbanks” on either side of my driveway were 8 feet to 14+ feet high where that big Walters snowplow with it’s giant “V” blade and 12 foot “wing” blades pushed it out of the road. It looked like this one, …. but without the painted “smile”. http://roadsidewonders.net/wp-content/uploads/2012/12/plow3.jpg

    Well now, when Spring arrived and all or most of the snow melted …… all my Pine trees looked fine n’ dandy n’ green ….. and I was “a happy camper”. But then I noticed some of them were turning “brown”. And then more n’ more of them were turning “brown” … so I investigated my problem … or my Pine tree’s problem. And guess what I found to my surprise?

    90+% of those young Pine trees had no bark on their trunks for like 2” up from ground level …. and they were all dying or dead. My only explanation for that tragedy was, …. given the depth of the frozen ground that winter …. the Field Mice could not find enough food to eat so they were forced to eat the bark off of my Pine trees in order to survive the winter.

    Education is not only costly, ….. it’s a learning experience.

  44. Reply to Samuel C Cogar ==> Yes, the culprit was most probably mice or voles, both can cause that kind of damage. The Washington Native Plant Society suggests:

    BASAL WRAPPING

    Grass stands tend to harbor large populations of meadow mice that will girdle tree seedlings and saplings. To protect plants from girdling, wrap the base of eacg plant with aluminum foil, or with a manufactured basal wrapping material. The wrapping should begin just below the soil line and should extend up the trunk for 8 inches, or to the first main lateral branch, whichever is less. After wrapping the trunk, secure the basal wrapping material around the trunk with filament-reinforced strapping tape or staples.

    Sorry for your loss…can be disheartening after all that work and time. Nature is a funny old thing sometimes.

  45. usurbrain says:
    July 7, 2014 at 11:20 am

    Here is one set of freeze depth data. It shows about a foot average for VT.
    ——————

    usurbrain, such “freeze depth data” is actually “rule-of-thumb” data for how deep “bare” ground will freeze given the normal winter temperature for a given locale so that residents/contractors will know how “deep” to bury their utilities. In most parts of WV it is 18”. In upstate NY where I lived it was 36” min. The winter of 77’ was extremely cold and little to no snow …. and thousands n’ thousands of “waterlines” in WV, etc. froze solid.
    =================

    usurbrain says:
    July 7, 2014 at 12:26 pm

    Many years ago I lost a beautiful Hemlock. The local AG Ext. told me I should have watered it every few weeks in the winter or put a “sealer” on the needles.
    ————–

    usurbrain, you were wasting water, ….. the “root hairs” die off in the fall ….. and re-grow in the spring. There is no photosynthesis activity, thus it needs no water. You only got problems if the roots dry completely out. Too much water in tree in wintertime is “bad”, it will freeze, ya know. The H2O in a tree is what causes it to “explode into splinters” when hit with a lightening strike.

    Most winter “kill” is due to extreme “windchill” …. and there are no “rules” that tell you when or where that “windchill” is going to occur. Of course it is always the worst if coming from the North or Northwest. Like that Polar Vortex that froze a lot of arses back in January.

    OR, if your locale gets 2+ weeks of really warm temperatures during mid to late winter ….. and then it turns “blue” cold again …. then “Big trouble in River City”. Some trees and shrubs will “think” it’s Springtime and will get with the “plan” … and then will get “whammied”. Forsythias bushes are noted for doing that.

  46. Kip Hansen says:
    July 8, 2014 at 11:29 am

    Sorry for your loss…can be disheartening after all that work and time. Nature is a funny old thing sometimes.
    —————

    Kip, I have a better (nature funny) story than my afore one, concerning “BASAL WRAPPING”, ….. iffen you are interested?

  47. Reply to Cogar ==> Every good story deserves to be told. Let’s hear it!
    ———————

    When I moved back to WV I purchased a home in a small Town. It is on a large “city lot” with my backyard bordering on a small river (30’- 50’ wide) that flows through the Town. Now even though there is a large Corps of Eng flood-control dam just up-river, my back yard will flood on rare occasions and be covered by 3’ to 4’ feet of water.

    Anyway, I love fruit trees and one year I planted about 12 peach tree seedlings on the back lot close to the river. They all grew fine and were like 10’ to 12’ feet high and were producing peaches (Red Clings). Then one night a beaver came swimming up or down the river and found my peach trees and decided it wanted one. When I seen it the next day, one was “cut” half way thru like 20” off the ground.

    Well now, I went to the store post haste and purchased a roll of 4” wide 1/2′ inch welded-wire fencing … and spent the next couple days “basal wrapping” all of my peach trees with that welded-wire. I was then a happy camper knowing that my trees were safe from that “Big-toothed” rodent, …… or so I thought.

    But wouldn’t ya know it, …. t’was a couple years later, in the late Fall, there was a huge rainstorm and the Dam filled up and the river rose and covered my back lot. And a day or so after all the water receded and headed for the Ohio River, I took a stroll down toward the river, ….. and I’ll be damned if there wasn’t 3 more of my peach trees knawel more than half-way through right above the top of my welded-wire wrapping.

    That beaver had swam up to my trees in the night time and “chewed” until it got tired of chewing, I guess. It was probably thinking ….. “I’ll fix you Sam C, for trying to fence me out”.

    Cheers

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