BAD YEAR: The verdict is in, and it doesn’t look good: “”Less
than spectacular”” fall foliage, according to Penn State’s College
of Agricultural Sciences.[neWLine]

“”Due to the extremely hot, dry weather this summer, this fall’s
display will not be one of our best. In fact, some people are
probably already starting to see that some leaves are going from
green to dull brown,”” said Marc Abrams, professor of forest
ecology and physiology.[neWLine]

“”I think we have to lower our expectations on what we hope to
see this year because the climate has put tremendous stress on some
tree species,”” he added.[neWLine]

The hot, dry conditions may also affect the timing of the
foliage coloration. “”Normally this level of drought would make
coloration occur a week or so early,”” he says. “”But it has stayed
warm the whole way through September, and that will delay the
display.””[neWLine]

“”Those opposing forces are likely to mitigate each other to
some extent, so we should see our foliage colors peak in the second
week of October, as usual.””[neWLine]

For about 20 years, Abrams has studied how seasonal
precipitation and temperature influence timing and intensity of
fall colors.[neWLine]

“”We believe that clear, bright days, low – but not freezing –
temperatures and dry conditions promote the best fall colors,”” he
says.[neWLine]

Cooler temperatures signal deciduous trees to stop producing
chlorophyll, the green pigment responsible for photosynthesis, he
explains. The chlorophyll breaks down and disappears, unmasking
other leaf pigments.[neWLine]

It’s these other pigments – called xanthophylls and carotenes –
that create the yellows and oranges seen in the leaves of yellow
poplar, hickory, sycamore, honey locust, birch, beech and certain
maples.[neWLine]

After chlorophyll production stops, trees also produce another
pigment in their leaves called anthocyanin which creates the
brilliant reds and purples seen in maple, sassafras, sumac, black
gum and purple oak.[neWLine]

The amount of anthocyanin produced each year is related to
starch levels in the tree. Trees often produce less starch during
droughts.[neWLine]

“”One thing that I have been impressed with in my 20 years of
gauging foliage is the resiliency of the display,”” Abrams
said.[neWLine]

“”This year I think we may see good color, but perhaps not great
color. People should go out and search for those pockets of great
color, because they will be there. They just may be a little harder
to find this year than usual.””