Spring Leaves Fall........

While I was out walking the girls I looked for leaves on the ground......   I had found previously, that some of the falling leaves are green, IE still viable, not dead.  You can see the leaf veins.  They transport water out through the leaf.  The main vein runs from the stem to the end.  Off the main vein are secondary veins  that out the leaf and then transports sugars out and down the tree.
     The leaf color is changing.  Where the leaf is still green, the leaf is capable of feeding the tree.   Where the leaf is yellow  it is no longer viable, that is able to support tree life and function.  When the leaf is brown, it has died.
      The sun is strong now.  The trees are waking up  or fully awake.  The buds are swelling in the petioles and pushing off all leaves, even the ones that are still viable from last year.   The tree is getting ready for a whole new growing season.