How to tell when tree first changes color

Discussion in 'Landscape Architecture and Design' started by JRSlawn, Oct 30, 2004.

  1. JRSlawn

    JRSlawn LawnSite Senior Member
    Posts: 637

    Is there a web site that tells aproximent time leaves from different species will change their color? Working on school project need help asap

    Thanks,

    Jeff Smith
    JRS Lawn & Landscape
     
  2. D Felix

    D Felix LawnSite Bronze Member
    Posts: 1,898

    I don't know for sure if there is or not, but I doubt it.

    Reason being that so many factors are involved it's not an exact science. The biggest factor is length of darkness, IIRC, not length of daylight. But you also need to take into consideration soil moisture, average ambient air temp, etc, etc. Not to mention geographic location. I know MI (LP) trees are usually about 2 weeks or so ahead of ours here in IN. And in IN, from north to south can vary by 2 weeks too....

    Good luck with your project, let us know if there is anything else that we can help with.


    Dan
     
  3. Coffeecraver

    Coffeecraver LawnSite Senior Member
    from VA.
    Posts: 793

    I posted this eariler maybe it will help

    Why do leaves change color?

    --------------------------------------------------------------------------------

    A chain reaction occurs when sunlight strikes the pigment in leaves, allowing
    us to see various leaf colors throughout the year. Four broad categories of
    pigment play a crucial role in autumn beauty: chlorophylls, carotenoids,
    anthocyanins, and tannins.

    During the spring and summer, leaves are the principal site for the
    photosynthetic process that transforms carbon dioxide and water into the
    carbohydrates that fuel tree growth. This food-making process takes place
    in numerous cells containing chlorophyll, the pigment that gives leaves their
    green color.

    As days shorten and temperatures cool in autumn, the synthesis of new
    chlorophyll drops off, green color disappears, and the rate of photosynthesis
    declines. Trees become frugal and more efficient, pulling nutrients such as
    nitrogen and phosphorus into twigs and branches for winter storage, further
    enhancing the loss of chlorophyll.

    Along with chlorophyll, leaves contain yellow or orange carotenoid, the same
    pigment that gives carrots their familiar color. Masked for most of the year
    by chlorophyll, the carotenoids reveal themselves in autumn, most noticeable
    as yellows and golds in tree species such as Norway maples, Ohio buckeyes,
    sycamores, birches, and hickories. For example, the golden yellows seen in
    beech leaves result from the presence of tannins and carotenoid pigments.

    The vivid pink, red, and purple leaves seen on maples, sassafras, sumacs,
    white and scarlet oaks, and many other woody plants are formed by
    reactions between various sugars and complex compounds called anthocyanins.
    A mixture of red anthocyanin pigment and yellow carotene often results in
    the bright orange color seen in some species of maples.


    Fast Facts: Autumn Colors
    Fertile soil enhances the intensity of reds in leaves.
    The more light a leaf is exposed to, the more likely it is to turn red.
    Weather conditions most favorable to brilliant color are warm sunny days
    followed by cool nights with temperatures below 45 degrees (not to freezing
    levels).
    Rainy or cloudy days near "peak coloration time" will dampen the intensity
    of autumn color by limiting photosynthesis.
    Freezing temperatures and heavy frost can kill the brilliance of autumn color
    by severely injuring leaves before pigments are fully developed.

    The International Society of Arboriculture (ISA) is a nonprofit organization
    supporting tree care research around the world. Headquartered in
    Champaign, Ill., ISA is dedicated to the care and preservation of shade and
    ornamental trees. For more information, contact a local ISA Certified
    Arborist or visit www.treesaregood.com.
     

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