Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Taiga or boreal forests advancing north?

  1. Feb 6, 2009 #1
    Anyone know of evidence, to which you can refer me, of boreal forests advancing northward due to global warming, along with animal species using that habitat?

    Thanks to all.
     
  2. jcsd
  3. Feb 6, 2009 #2

    CRGreathouse

    User Avatar
    Science Advisor
    Homework Helper

    Forests, especially boreal forests, move too slowly to react to a trend this short (if, in fact, it is a trend at all!). Watching animals is much more likely to find results.

    I have heard anecdotal evidence of animals moving south, but I know of no studies.

    I also wonder how this can be done fairly, as there will be relocation of habitat without climate change. How do you properly compare the movement of (presumably many) species slightly southward with (presumably few) species moving slightly northward?
     
  4. Feb 6, 2009 #3

    turbo

    User Avatar
    Gold Member

    Watching the animals can be pretty iffy, too. We sometimes have influxes of Snowy Owls in Maine in winter. That doesn't mean that they are moving this way. They may be coming here because lemmings (their staple food) are in short supply, or they may be coming here because a really good lemming population the previous year(s) ensured successful reproduction and resulted in overcrowding and more competition for territory. Without long-term studies on the ground, we'll never know.
     
  5. Feb 7, 2009 #4
  6. Feb 7, 2009 #5

    Evo

    User Avatar

    Staff: Mentor

    Apparently you have linked to the wrong source. Your link is about wildfires in the Western US and is an examination of land use, temperature and drought.

    What does this have to do with the topic of evidence of forests moving north?

    Also, your link does not even support your statement.
     
  7. Feb 7, 2009 #6
    Moreover it seems reasonable to expect that wild fire occurance is mainly a function of the amount of tinder and wood, or forests maturing.

    Anyway advancing boreal forests to way up north has occured during the Holocene Thermal Optimum ( McDonald et al 2000 )
     
  8. Feb 7, 2009 #7

    CRGreathouse

    User Avatar
    Science Advisor
    Homework Helper

    Ah. In that case forget what I said about animals -- I know much more about plants (well, North American biomes) than about animal migratory patterns.

    Surely in modern times it's primarily a function of human fire suppression? Although I suppose it comes to the same thing -- quashing small fires leads to buildup of wood on the forest floor that allows large fires to occur.
     
  9. Feb 7, 2009 #8

    Xnn

    User Avatar

    Here is a link to a news story of studies detailing migrations due to climate changes:


    http://www.cbsnews.com/stories/2003/01/02/tech/main534993.shtml

     
  10. Feb 7, 2009 #9

    Xnn

    User Avatar

    A Sooty Copper...

    attachment.php?attachmentid=17451&stc=1&d=1234056032.jpg
     

    Attached Files:

  11. Feb 8, 2009 #10
    I'm surprised at the claims of cause. You need to remember that coincidence does not = causality.
     
  12. Feb 9, 2009 #11
    Grasslands following forests northward where forests previously dominated is also a sign of global temperature change of whatever origin. Although I am totally convinced of human-related global warming, I am aware that it will take much more data and study for many ever to be convinced, and especially those who have vested personal or business interests in global warming NOT being human-related.

    The white man's forest fire suppression, of which I know a lot historically, has created a virtual tinderbox of unburned and everpresent understory fuel that was not present in quantity when native americans were the only residents here. By fire, the natives cleared the forest understory of brush, etc. primarily to allow easy usage of trade routes that crisscrossed America, Canada and Mexico north to south and east to west from coast to coast for milennia before the white man. Found evidence is plentiful that central natives traded for items indigenous only to the east and west coasts and the Gulf of Mexico, for thousands of years. Good trading routes were necessary for business and even survival then, and the natives wanted clear roads everywhere as their very existance depended upon these convenient and efficient trade routes being easily travelled at all times. Also, anyone familar with wildlife management knows that new grass and brush growth following fires has the best and most nutrients that allow larger and more healthy animal populations to thrive on which these natives depended for food. Natives regularly cleared huge areas of forest understory by fire that had no trade routes primarily to improve hunting.

    The white man coming here fatally upset previous native life and intertribal trade to extinction, so those forests with vast areas cleared of understory brush rapidly grew over with scrub underbrush that we whites thought had to be allowed to grow unabated, as that is the white man's idea of "natural", with all resultant forest fires suppressed. As a result of what has happened since, the best of these two opposing philosophies is plainly evident to me.
     
    Last edited: Feb 9, 2009
  13. Feb 11, 2009 #12

    turbo

    User Avatar
    Gold Member

    The National Audubon Society has released their analysis of the changes in bird ranges over the past 40 years. The birds that extended their ranges northward outnumber by 2:1 those that have spread south, an on average, they have moved north about 40 miles in 40 years. Despite some record cold this year, our winters are getting warmer and have been for ever since I was a kid (longer than the Audubon study). We had no turkey vultures when I was in my teens - now they are ubiquitous. Goldfinches were a rare occurrence in the winter months - now large flocks of 20-30 show up at my feeder every day, and they are accompanied by Pine Siskins and Redpolls - birds that normally showed up in early-to-mid spring. I had attributed some of these appearances to human feeding, micro-climates and changes in habitat, but the Audubon folks believe that the weight of the evidence points to warming as the prime factor. We'll see...

    http://news.yahoo.com/s/ap/20090210/ap_on_sc/birds_global_warming;_ylt=ArNloYzV.a1mC48jJXZJL02s0NUE;_ylu=X3oDMTFlZWk1YWo2BHBvcwMxMDgEc2VjA2FjY29yZGlvbl9zY2llbmNlBHNsawNzdHVkeWJpcmRzc2g- [Broken]
     
    Last edited by a moderator: May 4, 2017
  14. Feb 11, 2009 #13
    Here is a the map from the Audubon Society showing migration patterns of the species.

    BACC_map.jpg
     
    Last edited by a moderator: May 4, 2017
  15. Feb 11, 2009 #14

    CRGreathouse

    User Avatar
    Science Advisor
    Homework Helper

    Curious. Two-thirds is a big fraction, enough to suggest that something serious is going on with North American climate. But why do they 'cook the books' by showing 20 species moving northward and 0 southward? That's nonrandom with confidence 99.97%.

    Edit: they picked the species that moved most -- that explains it.
     
    Last edited: Feb 12, 2009
  16. Feb 11, 2009 #15

    turbo

    User Avatar
    Gold Member

    They are just showing the 20 species with the most movement over that period, and presumably the species with the most movement are the ones moving north. What is surprising is that it appears to be a national trend. I had only considered Maine, and since we have been getting warmer winters for over 40 years, I was not surprised to see winter accidentals getting more and more common. Also, I have not seen a Boreal Chickadee for years - they are staying in Canada, I guess. Still, weather (as opposed to climate) has an effect. We have had a cold winter so far, and unlike previous winters we have not had a single tufted titmouse at the feeders. Usually, one or two of them would flock with the black-capped chickadees in winter.
     
  17. Feb 11, 2009 #16

    turbo

    User Avatar
    Gold Member

    BTW, I routinely see wild turkeys all winter. Since I live in central Maine, the Audubon chart is badly skewed. Since wild turkeys have been re-introduced to Maine, they have thrived and their winter range has been moving farther north over the last couple of decades. I drove into town to buy some gas today and on the way home, I saw a flock of at least 20 of them in somebody's front yard.

    We had a LOT of snow last winter. That didn't slow down the wild turkeys. I shot this from the window in back of my computer, and I was standing at the time.
    turkey.jpg
     
  18. Feb 11, 2009 #17

    Evo

    User Avatar

    Staff: Mentor

    Not unusual, since we know forests existed near the north pole in the past.

    http://pubs.aina.ucalgary.ca/arctic/Arctic43-4-331.pdf

    I love that turkey picture!!
     
    Last edited by a moderator: May 4, 2017
  19. Feb 11, 2009 #18

    turbo

    User Avatar
    Gold Member

    I'd rather not be shooting though a double-pane Harvey window, but that's the best I could do. Notice that I did not completely crop out the window-frame on the right side, thus thus the fade-out.
     
  20. Feb 12, 2009 #19

    Astronuc

    User Avatar

    Staff: Mentor

    We have chickadees, titmice, goldfinches and pine siskins at our feeders. I was really surprised to see them when it was 20°F outside. I would have thought they would have gone south - NJ, Maryland, Virginia or Carolinas for the winter. We're having a more typical winter this year, otherwise our winters have been warmer.

    I've seen a nuthatch and a few purple finches during the last couple of weeks. We have at least one pair each of downy and hairy woodpeckers, and a Melanerpes carolinus (Redbellied woodpecker). The downies and haries prefer the suet, while the Redbellied prefers the seed.
     
  21. Feb 12, 2009 #20

    CRGreathouse

    User Avatar
    Science Advisor
    Homework Helper

    turbo-1: Thanks for pointing that out, I missed that. I edited my post to make it clear. And I love the turkey picture!
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Taiga or boreal forests advancing north?
  1. North Cliff failure (Replies: 4)

Loading...