| [College of ACES] | [University of Illinois] | [Illinois CES] |
Green leaves are green because they have chlorophyl. They are therefore
capable of photosynthesis. All photosynthetic matterial can photosynthesise
but it does not meen that it does so continuosly or efectively.
For example photosynthesis does not occur at night. It occurs at low levels
and sometimes not at all depending on temperature (too hot or too cold)
I am not sure that this gives a conifer or evergreen some advantage of survival.
Whilst they may capture more energy more is also used in respiration. Lastly the
real suvivors broadleaf tropical and temperate evergreens. Many shed their leaves regularly
as all tissue is damaged by sunlight (strange system hey?). These trees have no advantage
over deciduos trees. There is an amazing balace of Carbon in a tree. The tree can burn it
for respiration, store it as lipids and starch, convert it to new tissue, or pay TAXES to the
rhyzosphere. More photosynthates does not mean more stored energy it means more of everything
in balance.
Lastly deciduous trees do not lose the green colour. They simply stop using energy to maintan
colour. There are some good detailed expanations of this process in texts and on the net.
Hope this makes thing clearer.
MARK