The
yungas
is
the
term
applied
to
the
humid,
subtropical
band
of
the
Argentinian
northwest
that's
squeezed
between
the
flat
chaco
to
the
east
and
the
Andean
pre-cordillera
to
the
west,
dropping
south
from
the
Bolivian
border
through
Jujuy
and
Salta,
Tucumán
and
into
Catamarca.
Abrupt
changes
of
altitude
in
this
band
give
rise
to
radical
changes
in
the
type
of
flora,
creating
wildly
different
ecosystems
arranged
in
tiers.
All
are
characterized
by
fairly
high
year-round
precipitation,
but
have
distinct
seasons,
with
winter
being
the
drier.
The
lowest
altitudes
are
home
to
transitional
woodland
- no
longer
the
thorn-scrub
of
the
Chaco
but
retaining
some
varieties
typical
of
the
plains
to
the
east
-
and
lowland
jungle
(
selva
pedemontana
),
rising
up
to
about
600m.
Most
of
the
trees
and
shrubs
in
these
lower
levels
are
deciduous
and
have
showy
blossoms:
jacarandá
,
fuchsia,
pacará,
palo
blanco
and
amarillo,
lapacho
(or
tabebuia
),
timbó
colorado
(the
black-eared
tree),
palo
borracho
(
chorisia
or
yuchán
),
and
Argentina's
national
flower,
the
ceibo
.
Much
of
this
forest
has
been
hard-hit
by
clearance
for
timber
and
agriculture,
especially
sugar-cane
plantations.
Above
600m
starts
the
most
famous
yungas
habitat,
the
montane
cloudforests
(
selva
montana
or
nuboselva
) -
one
of
the
country's
most
diverse
and
interesting
ecosystems,
and
best
seen
in
the
national
parks
of
Calilegua
in
Jujuy,
and
Baritú
and
El
Rey
in
Salta.
The
selva
montana
is
split
into
two
categories:
lower
montane
forest
(
selva
basal
),
which
rises
to
about
1000m;
and
true
cloudforest,
which
is
found
as
high
as
2200m
and
depends
for
its
moisture
on
winds
blowing
westwards
from
the
Atlantic.
These
forests
form
a
gloomy,
impenetrable
canopy
of
tall
evergreens
-
dominated
by
laurels
and
acacia-like
tipas
at
lower
levels,
and
yunga
cedars,
horco
molle,
nogal
and
myrtles
higher
up -
beneath
which
several
varieties
of
cane
and
bamboo
compete
for
the
scarce,
mottled
sunlight.
The
tree
trunks
are
covered
in
thick
moss
and
lichen,
lianas
hang
in a
tangle,
epiphytes
and
orchids
flourish,
while
a
variety
of
bromeliads,
heliconias,
parasites
and
succulents
all
add
to
the
mysteriously
dank
atmosphere.
On
the
tier
above
the
cloudforest,
you'll
find
typically
single-species
woods
of
alder,
nogal
or
mountain
pine
form
the
bosque
montano
at
1500-2400m,
where
temperatures
at
night
and
in
winter
can
be
very
low.
Above
this
begins
the
pre-
puna
highland
meadows
(
prados
) of
stunted
queñoa
trees,
reeds
and
different
sorts
of
puna
grasses.
