The
Park’s
geomorphology
constitutes
an
infinite
succession
of
small
hills
which
are
the
result
of
thousand-year
old
river
straits
consequently
giving
the
area
impressive
biodiversity.
The
Park
comprises
important
river
basins
of
the
rivers
Napo
,
Yasuni,
Tiputini,
Nashino,
Cononaco
and
tributaries
of
rivers
Curaray,
which
borders
the
Park
towards
the
south.
From
the
town
Francisco
de
Orellana
(Coca)
towards
Nuevo
Rocafuerte,
the
River
Napo
extends
for
approximately
300
km
,
creating
more
than
120
islands
along
the
way.
It’s
possible
to
navigate
the
entire
river.
Other
rivers
in
Yasuni
National
Park
have
different
origins.
Some
originate
in
the
Andes
,
known
as
white
waters
due
to
high
quantity
of
sediment
which
they
carry
from
the
mountains.
Others
originate
in
the
Amazon
known
as
clear
waters
given
that
they
contain
a
certain
amount
of
decomposing
vegetation.
Finally,
so-called
black
waters,
due
to
the
permanent
contact
with
dead
leaves
and
their
tannin,
which
colours
the
water
and
from
where
palm
swamps
originate.
According
to
Holdridge
Classification,
the
entire
is
recognised
as
being
tropical
rainforest.
Within
this
three
different
types
of
jungle
have
been
identified
–
firm
terrain,
not
subject
to
flooding
and
located
in
the
upper
sector;
seasonal
forest,
subject
to
seasonal
flooding
and
permanently
flooded
forest
also
known
as
igapo
vegetation.
In
spite
of
the
fact
that
the
Park
and
its
ecosystems
are
in
exceptionally
good
condition,
threats
to
the
pristine
state
of
the
Park
do
exist,
mainly
from
petroleum
companies
and
increased
human
settlement
in
the
zone.
Last
Updated
21st
July
2006
(DLW)
