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Tropical Rainforest
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Located around the Equatorial regions
Hot temperatures and rain year round
No seasons
Convectional rainfall
Layers
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Emergent Layer giant trees
thrust above the dense
canopy layer and have huge
mushroom-shaped crowns.
These trees enjoy the greatest
amount of sunlight but also
must endure high
temperatures, low humidity
and strong winds.
Canopy Layer The broad,
irregular crowns of these trees
form a tight, continuous
canopy 30 to 50 m above the
ground. The branches are
often densely covered with
other plants (epiphytes) and
tied together with vines
(lianas).
Understory:
Dark, relatively open and contains
young trees and leafy herbaceous
plants that tolerate low light.
Forest Floor
The forest floor receives less than
2% of the sunlight and
consequently, little grows here
except plants adapted to very low
light. On the floor is a thin layer of
fallen leaves, seeds, fruits and
branches that very quickly
decomposes.
Only a thin layer of decaying organic
matter is found, unlike temperate
forests.
• Tress buttressed at the
base
• Leaves large
• Thousands of species but
individual species spaced
widely apart
• Nutrients are in the
biomass not the soil
• Nutrient Recycling
Constant warmth and
moisture promote rapid
decay of organic matter.
When a tree dies in the rain
forest, living organisms
quickly absorb the nutrients
before they have a chance to
be washed away.
• When tropical forests are cut
and burned, heavy rains can
quickly wash the released
nutrients away, leaving the
soil even more
impoverished.
• Vegetation protects the
soil.
• Through the nutrient
cycle, vegetation helps to
maintain the soil fertility
• When it rains, nutrient
entre the soil
• Plant roots quickly absorb
the dissolved nutrients
• Small organism eat leaves
and litter
• The rain forests are home to half of the
Earth's plant and animal species.
• They are winter homes to many birds that
breed in temperate latitudes.
• home to tribal cultures that have survived
• The forests are a potential source of
medicinal plants that may benefit everyone
on Earth.
• Tropical rain forests help maintain global rain
and weather patterns.
• The rainforest contains more than half
of Earth's plant and animal species,
even though rain forests cover only
about 6% of the earth's surface.
• The average humidity in the rainforest is
high, ranging from 77% to 88%. The
average temperature is at least 28 to 35
degrees.
Tropical Monsoon
• Less precipitation and dry season
• Lush vegetation but more open and lose
leaves in the dry season
• Growth not as great and fewer species
• Mesotherms adjust to moderate heat
• Many lianas (woody vines) and
herbaceous epiphytes (air plants, such
as orchids are present.
• Monsoon forests are especially well
developed in Southeast Asia and are
typified by tall teak trees and thickets of
bamboo.
Tropical Savannah
• Grasses
• Parkland
• Wet/dry seasons
Tundra
• Long cold winters and short summers
• Permafrost
• Cold climate leads to short
growing season
• Soil is poor in nutrients
• An under-layer of soil
called permafrost remains
completely frozen at all
times allows no room for
deep rooting plants and
trees. This also prevents
water from percolating into
the ground and as a result,
bogs, ponds and small lakes
cover the landscape
providing a perfect breeding
ground for mosquitoes and
other insects.
• This abundant food brings
many waterfowl to nesting
grounds in the tundra.
• Plants are extremely resilient with short, shallow roots
close to the surface,adapt to wet soil in the short summer
• Plant life consists of shrubbery, lichen, and moss. No trees!
Taiga, Boreal Forest
• Taiga is also know as Coniferous or Boreal Forest.
• Largest terrestrial biome on earth which includes a variety
of climate conditions, from moderate to severe.
• Generally, winters are long and cold, and summers are
mild and short.
• Precipitation is moderate
(20 to 60 cm) and
evaporation is low.
• Soils are thin, nutrient
poor and acidic
• Trees adapt by producing
a dense network of
shallow roots, grow small
needle shaped, wax coated
leaves, shed their needles
• In the summer the soil
is often waterlogged,
forming acidic bogs
(muskegs)
• Dominated by black
spruce, fir, pine,
poplar, and aspen.
Temperate Rainforest
• Temperate rainforests are
among the rarest
ecosystems in the world,
and originally comprised
less than .02 per cent of
Earth's land surface.
• Approximately half of all
original temperate
rainforests have been
logged.
• Also called Coniferous
Evergreen Forest
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temperate rainforests are found in
the middle latitudes. Where milder
climates prevail, deciduous tree
species dominate, while coniferous
tree species prevail where colder
winters occur.
Favorable growing conditions - a
moderate climate, minimal changes
in the seasons, and ample rainfall allow trees to grow all year in
temperate rainforests. Trees are
often enormous.. For example, in
Washington State's Olympic
Peninsula, a 127-metre (420 foot)
Douglas fir was chopped down in
1895. Redwoods dominated
California's temperate rainforests,
and this fir tree was taller than a
modern-day Redwood by 18 metres
(60 feet). Sitka spruce, cedar and
hemlock, fir are typical trees found
in this biome.
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Coastal temperate rainforests have four
defining characteristics: a proximity to
oceans, presence of coastal mountains,
cooler summer temperatures and high
rainfall levels
One of the most fascinating aspects of
the coastal temperate rainforest is the
blurred boundary between terrestrial and
marine ecosystems.
These forests have abundant epiphytes
(plants that live on other plants); and they
have a dense shrubby understory, even
the surfaces of trees support other plants
and lichens.
Conifers have adapted to poor,acidic soil
by developing a root systems which picks
up nourishment from the top soil layer
Trees cone shape with thin flexible
branches so snow will fall off easily and
strong winds will not break branches.
Cones protect seeds from cold winter
weather and waxy needles minimize
water loss through transpiration in the
summer.
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Problems:
Clear Cutting
Logging
Salmon at risk
Species depletion
Temperate Deciduous Forest
Found in the mid-latitudes
Characteristics of this biome influenced by patterns of temperature
and precipitation. There are four definite seasons.
During the fall, trees change color and
then lose their leaves. This is in
preparation for the winter season which is
cold. Trees have adapted to the winter by
going into a period of dormancy or sleep.
They also have thick bark to protect them
from the cold weather. Trees flower and
grow during the spring and summer
growing season. Many different kinds of
trees, shrubs, and herbs grow in
deciduous forests. Most of the trees are
broadleaf trees such as oak, maple,
beech, hickory,aspen and chestnut. There
are also several different kinds of plants
like mountain laurel, azaleas and mosses
that live on the shady forest floor where
only small amounts of sunlight get
through.
Leaf litter adds nutrients to the soil
annually and enjoyed by the bugs.
Mid-Latitude Grassland
Steppe, Prairie
• Grassland biomes are large, rolling terrains of
grasses, flowers and herbs.
• Latitude, soil and local climates for the most part
determine what kinds of plants grow in a particular
grassland.
• A grassland is a region where
the average annual
precipitation is great enough
to support grasses, and in
some areas a few trees. The
precipitation is so erratic
that drought and fire
prevent large forests from
growing. Grasses can
survive fires because they
grow from the bottom
instead of the top. Their
stems can grow again after
being burned off.
• Grasses can be tall (1.5m) or
short. Species distribution
depends on moisture
availability and heat.
Mediterranean, Schlerophyll
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This subtropical Mediterranean biome is composed of small scattered trees
(often less than 3m high),thorny bushes and shrubs.
Also called the Maquis in Europe or Chaparral in California.
Cactus and other water storing plants do well in this environment. The cacti
often form dense thickets.
The climate in this area is unique with the wet season occurring in winter and
summer drought (annual rainfall of 15-40 inches)
Olive
Broom
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Most of the plant growth is leafy,
leathery and relatively short. It is
important for plants to be drought
resistant, to survive the short wet
winters and long dry summers.
Plants often have deep roots to tap
water, but also help stabilize the soil
during the brief rainy season.
The geography of this region begins
at the seashore and extends
through rolling farmlands, with
grazing and cultivation, into the
mountains
Fire is a major factor in the
dynamics of this plant community,
and plants are adapted to fire, ie.
Crown-sprouting shrubs,and annual
fire-followers. Important as fire
thins out the vegetation. Extreme
heat needed to develop some
varieties of seeds.
Deserts
• Deserts cover about
1/5 of the planet
• Deserts found in
most latitudes
• Evaporation exceeds
precipitation, often
rain evaporates
before it hits the
ground
Desert Adaptations
• Soil coarse, sandy
• Vegetation limited but
specialized
• Plants are short,
spaced widely apart,
leaves are small, roots
can be long (tap root)
• Some xerophytic plants
have extensive root systems
to capture moisture in the
soil.
• Others have waxy leaves or
fleshy tissues to store
moisture. Enlarged green
stems like those found on
cacti take over the function
of leaves in photosynthesis.
• Some desert vegetation
may shed parts of branches
during extreme drought.
• Thorns for protection