Thou art an elm, my husband, I
a vine,
Whose
weakness, married to thy stronger state,
Makes me with thy
strength to
communicate
(‘Comedy of Errors’, ii.,
2)
The
Strangler Fig
Most
strangler trees found at Cloudbridge are fig trees, such as Ficus hartwegii, Ficus crassiuscula and the giant Ficus tuerckheimii
The
strangler fig tree has 4 different stages in its life: epiphyte, primary hemi-epiphyte, strangler and tree.
In
the
first stage, it grows up as an epiphyte. The seeds
inside the fruit are pollinated by tiny wasps that squeeze into the fig
to lay their eggs, but then lose their wings and die. Later, the figs
are
eaten by a wide range of animals like bats, birds, monkeys, coatis and
kinkajous that spread the excrement on branches and notches of tall
host-trees.
Then the
seeds germinate and grow as epiphyte (epi = on / phyte = plant) that
will use the host-tree as a physical support. Up there in the canopy,
the epiphyte can enjoy sunlight and intercept aerial-borne nutrients
contained in rain, mist and dust.
In
the
second stage is shown in the photo at right, where a Ficus vine begins its takeover of
an elm, Ulmus mexicana. The
epiphyte grows roots right down to the soil,
looking for higher resources in water and nutrients, becoming
a primary
hemi-epiphyte.
With an average pace of 5 meters a year,
these aerial roots can reach the ground within 4 or 5 years, depending
on
the host-tree’s size. Just before entering the soil, each individual
root
around the host-tree trunk divides into several thin roots, which means
several
sources of nutrients and water. Many scientists have tried to
understand
how roots can detect the close ground. Some explain this by minerals
contained
in both the sap of the roots and the water from the soil, stimulating
magnetism!
Once the roots reach the ground, they develop underground in a large
radius
to take as much of resources as possible.
In
the
third stage, the strangler function begins: sap
flows up the roots that grow thicker, meld together through a chemical
process, and slowly strangle the host-tree.
In
its
fourth stage, the strangler has reached its goal: to become a tall and
freestanding tree with branches,
leaves, fruits and flower. New branches sprout from the top and the
ficus begins to shade out the host tree. It appears that this shading,
rather than an actual “strangling” by the roots, is what normally kills
the host. The latticework of roots has formed a very stable trunk
around the host-tree that will disappear and decay inside the fig tree,
leaving it hollow.
Despite
its name, this tree plays an important role in the regeneration of the
tropical cloud forest: it uses a host-tree to become independent
and eventually replaces it. The fig itself then becomes a host
for
new epiphytes of all kinds.
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