Natural Regrowth
Parts of
the Cloudbridge reserve, notably those next to existing primary forest,
are given over to natural regeneration. This is slower than deliberate
reforestation but ensures consistency with the surrounding forest. Some
of Cloudbridge already consists of secondary forest. Dense shubbery and
light-loving pioneer species such as Guarumo (Cecropia peltata) prevail in these
areas. They play a key role.
 Cecropias
The
cecropia is well adapted to succeeding in cleared areas, whether the
disturbance is natural or human. To avoid the entangling vines of new
undergrowth, it grows to 5-10 meters before extending any branches. As
it grows higher, it discards the lower branches, giving creepers no
hold. At this point it shades out the undergrowth, allowing slower,
shade-tolerant canopy trees to
grow.
Azteca
Ants
and the Cecropia
Many
Cecropias are called myrmecophytes, plants that have a relationship
with ants. In the Cloudbridge area Cecropia trees most commonly provide
food and housing to species of Azteca ants. The stems of the trees are
largely hollow and provide a space for the ants to live and raise their
young. The leaves provide small white protein beads called Mullerian
bodies that contain glycogen, which the ants harvest as food. The tree
in turn benefits from having
the Azteca ants as they are said to protect the tree from both
herbivores and encroaching vegetation. When disturbed by insects or
small mammals the ants swarm out onto the trees surface to deter or
kill the invader.
The
queen
ants that first colonize the tree will chew through a soft area of the
stem and seal herself inside. Here she will raise a few workers who
will gather the Mullerian bodies and help her to raise more ants of all
casts. In one young tree there may be several different queens but as
the tree gets older one ant colony will usually dominate.
The
species of ant found in each tree is thought to vary with many criteria
some of which include the tree species, light availability, altitude,
disturbance levels and the presence of other ants in the same tree or
area.
The
Tree and
the Sloth
Sloths
are said to be everywhere in Costa Rican cloud forests. Each family of
sloths has
a peculiar dietary preference, and many three-toed sloths seem to have
chosen the
cecropia’s juicy leaves. Spider Monkeys have been seen at play in the
cecropias of Cloudbridge. Many kinds of birds eat, and then disperse,
the tree’s thick hanging fruits. Other birds eat the many insects that
thrive on the foliage. The Lineated Woodpecker actually pierces young
trees and branches to feed on the Azteca ants. |
