Willows pioneer new territories and create an environment that enables
other plants to gain a foothold. Their windblown seeds usually root in
sunny land opened by fire and agriculture. Since these trees require a
great quantity of water, the solution holes in the glades are favorable
sites. Seedlings grow, leaves fall, and stems and twigs die and
drop—contributing to the formation of peat. When this builds up close to
or above the surface of the water, it provides a habitat for other trees
such as sweet bay and cocoplum; with enough of these the willow head
changes character and becomes a bayhead.
Years ago, when alligators were plentiful, they weeded the
willow-bordered solution holes, keeping them open. Consequently, the
willow heads were typically donut-shaped. Today, however, alligators are
scarce and many of the willow heads have no ’gators. The solution holes
fill with muck and peat; relatively tall willows rise out of the deep,
peat-filled centers, with increasingly smaller ones toward the less
fertile edges, and the willow heads take on the characteristic
dome-shaped profile but not nearly the height of the cypress domes. They
have a clumpy, brushy appearance, seeming to grow right out of the marsh
without trunks.
[Illustration: POMACEA SNAIL—The sole food of the everglade kite]
[Illustration: EVERGLADE KITE]
[Illustration: Willow heads with alligator holes typically have a
doughnut shape—the gator hole representing the hole in the
doughnut.]
SPATTERDOCK
COASTAL PLAIN WILLOW
CATTAIL
DRY SEASON WATER LEVEL
Willow heads that do have alligator holes have a seasonal concentration
of aquatic animals and the birds and mammals that prey upon them. They
rarely support orchids or bromeliads, for the bark of the southern
willow is too smooth to provide anchorage for the seedlings of these
plants.
During drought periods willow heads, like bayheads, are vulnerable to
the fires that sometimes burn over the glades.