It’s almost time to start paying
attention to the emerging signs that our foliage is about to burst into its
fall colors – what one friend refers to as “the hunt for red October.” But this
year brings with it great uncertainty.
The massive defoliation throughout the region by winter moth and
gypsy moth caterpillars put great stresses on our trees, as has the
considerable drought we have experienced. Both of these factors have made the
always difficult job of predicting the timing and brilliance of the fall foliage
display even more difficult.
Local experts tell me that their
best guess is that we may experience a slightly muted display this year, and
the caterpillars are mostly to blame.
The trees that were defoliated in May and June – mostly in western
and southern Rhode Island, and to a lesser degree in the East Bay – produced
what botanist Keith Killingbeck calls “a second flush of leaves” in July. Most
deciduous plants can do this if the first batch of leaves becomes defoliated
early in the season.
But from what Killingbeck has observed, the new leaves appear to
be much smaller in size than the mature leaves that were consumed by the
caterpillars. And there may even be fewer leaves per tree compared to normal
years. This means there is less surface area to magnify the colors. So even if
the individual leaves are as beautiful as ever, the trees may not look as
stunning.
Killingbeck, a retired professor at the University of Rhode
Island, also worries that the process of producing that second flush of leaves
required so much energy that the trees may be too exhausted to complete the
metabolic processes that produce the colors. In a typical year, the trees suck
nutrients stored in the leaves back into the branches and root system before
the leaves fall. That, in a nutshell, is what causes the leaves to turn colors.
But the trees may not have the energy to go through that process, meaning the
leaves may still be partly green when they drop from the trees.
On the other hand, many oak trees appear to have aborted the
process of producing acorns this year, which may be a strategy to conserve
energy so they can experience a normal fall foliage season.
And if that’s not enough, the severe drought that much of the
region experienced might disrupt our fall colors, too.
“What normally happens in drought years is that the leaves are
lost earlier than normal, and sometimes if there’s been a severe drought, they
turn brown and drop rather than turning brilliant yellow or red,” explained
Killingbeck.
The effect of the drought could be reversed, however, if we get a
good dose of rain in the weeks leading up to the change of colors. If we do,
then the timing of the change and the brilliance of the colors may be
unaffected.
Too much rain at the wrong time, though, could also quash the fall
colors. Heavy rains during the peak of the foliage season could leach out the
compounds that provide the color through tiny fissures in the leaves.
All of which explains why it’s so difficult to predict what to
expect from our fall foliage. There are just too many competing factors to take
into consideration. So instead of worrying that this year’s colors will be a
disappointment, I’m just going to appreciate whatever we get and know that
we’ve got another shot at a spectacular display next year.
osmaniye
ReplyDeleterize
sakarya
samsun
sivas
HJZQQJ