Life in a Rotting Log
 You'll see a number
of rotting logs if you visit Cloudbridge
or in any part of the neotropical forest. Don't ignore them -- they
form
an essential part of the natural cycle of the forest. Far from being
"dead
trees," logs teem with life. Since living trees consist mostly of dead
wood
on the inside anyway, fallen logs sustain more living biomass when dead
than
when alive!
Natural
Gaps
Trees
that fall as a result of wind, lightening or landslides are an
essential part of forest growth — they open gaps for new trees to fill.
When light reaches
the forest floor, an whole succession of plants and trees begins. This
adds
diversity to a healthy forest.
Logs
Provide
Food and Energy
Wood-boring
insects such as termites and these beetles are the first to
penetrate wood. The tunnels they create open the wood to invasion by
bacteria
and fungi that feed on the wood, leading to its decay and the recycling
of
nutrients. In turn, the bacteria and fungi become part of a food web
for
many other creatures. fungi, and bacteria eat the log and help it to
decompose.
This decay can create water-filled cavities in the log that become home
to
aquatic organisms like tadpoles, and mosquito and damsel fly larvae.
The
red-eyed tree frog (Agalychnis callidryas) attaches its eggs
to leaves
overhanging water holes. On hatching, the tadpoles fall into the water.
 A dead log often
looks like a miniature forest. Mushrooms, lichens and liverworts
flourish in the rich moist environment. Seen here are the fruiting
bodies of the fungi. In the log, they put out extensive networks of
tiny threads called hyphae, that consume the plant matter and even can
trap and eat tiny creatures like nematode worms.
Logs
Offer Shelter
As
well
as being a source of food and energy, downed wood may be a safe
place to hide from predators, or to breed, or to shelter from heat,
cold
or storms. This frog, like other
amphibians, needs the shelter
and the moisture of the log and its plant life, because it drinks
through
its skin, not its mouth.
New Trees
From Old
Fallen
logs are also excellent nurseries for cloud forest plants. “Nurse logs”
can provide protection, more moisture, less competition from other
plants,
and sometimes greater nutrition than the forest floor. Soil and other
organic
matter that tend to gather uphill behind fallen logs also create rich,
sheltered
growing sites.
Enriching
the
soil
Dead wood
is a “savings account” of nutrients. As the wood decays, nutrients are
recycled back into the soil. Fallen logs also stabilize soils and
reduce erosion by wind and rain.
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