Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1907-10-18
BRATTLEBORO LOCAL NEWS
TREES IN THE FALL
Leaves Do Not Fall Off as a
Result of the Frost
Neither is the Frost Accountable. as
Commonly Supposed, for the Brilliant
colorng at This Time.

commonly Supposed FOR the Brilliant
coloring at This Time.
The heavy frosts of the early part of
the week, coming at the same time as
the wholesale falling of leaves from the
trees, brought into prominence the time
hunored misrepresentation which most
people have in regard to the causes of
the annual defoliaton. 1t Is commonly
said that the leaves fall because of the
heavy frosts, but in reality the frost is
not directly connected with the falling in
any way. Leaves fail from the trees be-
cause they are ripe and have ceased to
play any part I'm the life Of the tree.
Their function throughout the earlier
part of the year is to take food from the
air and convert it into forms which the
main tree can use in growth As the
season of rest for the tree comes, that
is, the time when all growth practically
ceases, the leaves lose their function and
become dead things of no further use to
the tree. When they become fully ripe
the cells I'm the tissue which Joins the
stem Of the leaf to the twig lose their
liquid cell contents and become dry and
| brittle. Before that takes place the stem
is plant and is rarely broken by even the
highest wind and most severe rain but
after the loss of the cell sap the lightest
breeze will break them OFF. The only
connection which the frost may have with
the falling is that it may hasten the
drying process.
The change In color of the leaves at
this season is also phenomenon COM
monty accredited to the action Of frost
when in reality 1t is due to the natural
process of .ripening. Except as the frost
may hasten the ripening process by dry
ing up the cell sap it has no direct con-
nection with the change In color The
green color of the leaves in their active
Ia 70 1na HV,Vsa
of chlorophyll contained in the surface
cells, more abundant on the upper side OF
the leaf In most trees but present in some
numbers on the under side. These glo-
budes have the function Of taking carbon
from the free carbon doXide in the air,
and reducing tito a form which the tree
can use in building up its tissues The
greater part Of the trees BULK is made
up of carbon, as shown in the process OF
making charcoal which is nearly pure
carbon. The process of taking the car
bon from the air can only be carried on
in sunlight which explains the greater
abundance of chlorophyll globules on the
| upper surface of the leaf where the sun
| light falls most strongly. The arrange
ment OF the leaves on the tree is merely
! an adaptation to secure the exposure OF
| the greatest possible chlorophyll bearing
surface to the sunlight
When the resting period in n trees
| ne beglnS In the rail-, the leaves lose
| their function of gathering carbon and
| the chlorophYll globules lose their use
| fulness They at once begin to break
| down into simpler chemical compounds
of predominating yellow color and the
! green of the earlier months is rather
! quickly replaced by yellow shades At the
| same time the sap i'm the cells in the
| leaf loses its function as transporter
| of the carbon and becomes merely O
! gradually drying up liquid With this
| change comes a general breaking dowr
| into chemical compounds of a reddish
color. The weather conditions during
! September and october govern the ra.
pidity with which the drying up process
goes on to some extent which accounts
! for the variation in the amount OF rec
in the autumn foliage of different sea.
| sons.
Still another process comes in to pro.
duce the intermediate shades Of color
The cells which form the main body Of
the leaf have a distinct color OF theil
own which is covered up by the NOR,
| brilliant green OF the chlorophyll bearinl
cells on the surface when the greer
disappears the color of the cells beneath
| becomes visible for the first time. Thi.
probably accounts for all the colors ex
ceft the bright rods and yellows pre-.
viously accounted for. The dark sole
red of the oak leaves Is without doub
| due altogether to this uncovering of tn,
lower layer of cells. This process ais,
comes in in all trees which change to 9
certain regular color year after year.