Transcript Tropical rain forests

ISC 201 Man and
Environment
2.The Biosphere
The biosphere is the earth envelope
– a thin realm composed of water,
land and air …. where organisms are
found, --- or a global ecosystem.
The largest communities on land are
called biomes. ??????
• Abiotic and biotic factors influence the
structure and dynamics of biomes
• Varying combinations of both biotic and
abiotic factors
– Determine the nature of Earth’s many
biomes
• Biomes
– Are the major types of ecological
associations that occupy broad geographic
regions of land or water
There is no equivalent term for large aquatic
communities because both have unique,
defined characteristics. ??????
Aquatic and terrestrial biomes
(Biome = major ecosystem type)
Terrestrial biomes:
- Tropical forest
- Savanna
- Desert
- Chaparral
- Temperate grassland
- Temperate deciduous forest
- Coniferous forest
- Tundra
Distribution of the Earth's eight major terrestrial biomes. (Adapted from:
H.J. de Blij and P.O. Miller. 1996. Physical Geography of the Global Environment. John
Wiley, New York. Pp. 290.)
http://www.physicalgeography.net/fundamentals/9k.html
Tropical rain forests or evergreen broadleaf forest:
The tropical rain forest is a forest
of tall trees in a region of yearround warmth (mean temp. 25OC).
An average of 50 to 260 inches
(125 to 660 cm.) of rain falls
yearly.
Almost all rain forests lie near the
equator.
Evergreen trees produce new
leaves and shed old ones through
the year. TRF produce more litter
than other forest biomes.
It is the richest biome, both in
different kinds of species found
and total amount of living matter.
The soil is highly weathered,
humus poor, and not good nutrient
reservoirs. WHY??
Rain forests
belong to the
tropical wet
climate group.
Rainforests now cover less than 6% of Earth's land surface.
Scientists estimate that more than half of all the world's plant
and animal species live in tropical rain forests. Tropical
rainforests produce 40% of Earth's oxygen.
WHY??
Tropical Rainforest
Tropical trees often have
buttressed bases to help
support their heavy aboveground biomass.
Important Facts:
-- Amazon rainforests produce
about 40% of the world's oxygen
-- One in four pharmaceuticals
comes from a plant in the tropical
rainforests
-- 1400 rainforest plants are
believed to offer cures for cancer
-- 40% of tropical rainforests have
already been lost in Latin America
and Southeast Asia
http://www.physicalgeography.net/fundamentals/9k.html
Tropical Forest: Vertical stratification with trees in
canopy blocking light to bottom strata. Many trees
covered by epiphytes (plants that grow on other plants).
Tropical deciduous forest: many
trees drop some or all of their
leaves during a pronounced dry
season.
Savanna
Savannas or
tropical savannas
are grasslands with
scattered droughtresistant trees that
generally do not 10
meters in height.
Tree and shrub
species shed their
leaves during dry
season to reduce
water loss.
Savannas are characterized by distinct wet and dry seasons. Temperatures
are hot all year long. Savannas support the richest diversity of grazing
mammals in the world. They have many types of plants and animals. Fire is
an important abiotic factor.
Tropical
Savanna
Savanna
vegetation is
typical composed
of a mixture of
grass and trees.
(Source: NASA Oak Ridge National
Laboratory (ORNL)
Distributed Active
Archive Center
(DAAC) Net
Primary Productivity
(NPP) Database).
http://www.physicalgeography.net/fundamentals/9k.html
Giraffes are a common
grazer on the African
savanna.
Savannas are also home
to a number of predator
species who prey on
grazing animals.
http://www.physicalgeography.net/fundamentals/9k.html
Savanna
Prairie is temperate grassland
Natural grassland
ecosystems are
dominated by
various species of
grass.
The dominant animals
are grazing and
burrowing types.
Grazing and periodic
fires keep shrublands
and trees from
encroaching on the
fringes of many
grasslands.
http://www.physicalgeography.net/fundamentals/9k.html
Prairie is a temperate grassland.
Marked by seasonal
drought and fires, and
grazing by large animals.
Rich habitat for
agriculture, very little
prairie exists in US today.
Common in organic rich
and black chernozemic
soil, so most grassland
ecosystems have been
modified by humans to
grow grain and other
dryland crops.
Chernozems are among the richest in nutrients and consequently
the most fertile in the world.
Chaparral
Dense, spiny,
evergreen shrubs,
mild rainy winters;
long, hot, dry
summers. Periodic
fires, some plants
require fire for
seeds to germinate.
This biome is sometimes also called Mediterranean
Scrubland or sclerophyll forest.
The Desert: Land of Little Rain
Desert habitat devoid of
vegetation.
Plants are droughttolerant (capable to
survive without water
for a long time).
Lizards are quite common in desert habitats.
Alarmingly, many parts of the world are undergoing desertification – the
wholesale conversion of grassland and other productive biomes to dry
wastelands.
http://www.physicalgeography.net/fundamentals/9k.html
Desert: Sparse rainfall (< 30 cm per year), plants and
animals adapted for water storage and conservation. Can
be either very, very hot, or very cold (e.g. Antarctica)
1000 year old Welwitschia plants survive the Namib desert
by catching dew off the ocean currents
Temperate Deciduous Forest
The temperate forest biome is
found in the middle latitudes
around the globe and this biome
is very seasonal. This biome is
characterized by a moderate
climate and deciduous trees.
Temperatures become cold
during winter.
Decomposition is not as rapid
as in the tropical rain forest, and
nutrients are conserved in
accumulated litter on the forest
floor.
This biome at one time, occupied northeastern North America,
Europe, and eastern Asia. It has been very extensively affected by
human activity, and much of it has been converted into agricultural
fields or urban developments.
Temperate Deciduous Forest: Mid-latitudes with moderate
climate, high rainfall (75-150 cm/y), distinct vertical strata:
trees, understory shrubs, herbaceous sub-stratum. Loss
their leaves in the fall, many animals hibernate or migrate
then. Original forests lost from North America by logging
and clearing.
Boreal Coniferous Forest
Cold Climate Forests:
The Taiga
The understory of boreal forest
habitats is usually poorly
developed due to low light
penetration.
Taiga lies bet. 45-57 N latitude, climate is cool to cold, vegetation are
needle leaf evergreen variety of tree species.
http://www.physicalgeography.net/fundamentals/9k.html
Coniferous forest (or Taiga): Largest terrestrial biome on
earth, old growth forests rapidly disappearing, usually
receives lots of moisture as rain or snow (40-100 cm/y).
Bears are common in the boreal forest ecosystem.
http://www.physicalgeography.net/fundamentals/9k.html
Tundra
The geographical
distribution of tundra biome
is poleward 60O N latitude.
Characterized by an
absence of trees, the
presence of dwarf plants.
Soil – permanently frozen
(permafrost). The
permafrost line is a physical
barrier to plant root growth.
Average temperatures in summer month is below 10o C.
Tundra: Permafrost (Permanent frozen ground), bitter
cold, high winds and thus no trees. Has 20% of land
surface on earth.
• The examination of Earth’s aquatic
biomes
30N
Tropic of
Cancer
Equator
Tropic of
Capricorn
Continental
shelf
30S
Key
Lakes
Coral reefs
Rivers
Oceanic pelagic
zone
Estuaries
Intertidal zone
Abyssal zone
(below oceanic
pelagic zone)
• Aquatic biomes
– Account for the largest part of the
biosphere in terms of area
– Can contain fresh or salt water
• Oceans
– Cover about 75% of Earth’s surface
– Have an enormous impact on the
biosphere
A. Aquatic biomes cover about 75% of the
earth’s surface
- Wetlands
- Lakes :- 2 Types of lake
- Rivers, streams
- Intertidal zones
- Oceanic pelagic biome
- Coral reefs
- Benthos
Freshwater Ecosystems
Lakes and Ponds - Standing Water
Deep lakes contain three distinct zones, each with its
characteristic communities of organisms.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/F/Freshwater.html
Freshwater Ecosystems
Lakes and Ponds
(Standing Water)
Littoral zone
The zone close to shore. Here light reaches all the way to
the bottom. The producers are plants rooted to the bottom
(like water lilies and cattails) and algae attached to the
plants and to any other solid substrate. The consumers
include
-- tiny crustaceans
-- flatworms
-- insect larvae
-- snails
-- frogs, fish, and turtles.
Freshwater Ecosystems
Lakes and Ponds
(Standing Water)
Limnetic zone
This is the layer of open water where photosynthesis can
occur. As one descends deeper in the limnetic zone, the
amount of light decreases until a depth is reached where the
rate of photosynthesis becomes equal to the rate of
respiration. At this level, net primary production no longer
occurs.
Freshwater Ecosystems
Lakes and Ponds
(Standing Water)
Limnetic zone
Life in the limnetic zone is dominated by:floating microorganisms - called plankton
actively swimming animals - called nekton.
The producers in this ecosystem are phytoplankton (algae).
The primary consumers include such animals as microscopic
crustaceans and rotifers - the so-called zooplankton.
The secondary (and higher) consumers are swimming insects
and fish. These nekton usually move freely between the littoral
and limnetic zones.
Freshwater Ecosystems
Lakes and Ponds
(Standing Water)
Profundal zone
The dark bottom region
This zone depends for its calories on the drifting down of organic
matter from the littoral and limnetic zones.
The profundal zone is chiefly inhabited by primary consumers that are
either attached to or crawl along the sediments at the bottom of the
lake, mainly insect larvae, scarvenger fishes. Such bottom-dwelling
animals are called the benthos.
The sediments underlying the profundal zone also support a large
population of bacteria and fungi. The decomposers break down the
organic matter reaching them, releasing inorganic nutrients for
recycling.
Wetlands: includes marshes, bogs, swamps,
seasonal ponds. Among richest biomes with
respect to biodiversity and productivity. Very few
now exist as they are thought of often as
wastelands.
Lake:- 2 types
Oligotrophic Lake: Nutrient poor, water is clear,
oxygen rich; little productivity by algae, relatively
deep with little surface area.
Lake:- 2 types
Eutrophic lake:
nutrient rich, lots
of algal
productivity so it’s
oxygen poor at
times, water is
murkier  often a
result of input of
agricultural
fertilizers
Rivers and Streams
The habitats available in
rivers and streams differ in
several ways from those in
lakes and ponds.
Because of the current, the
water is usually more
oxygenated.
Photosynthesizers play a minor role in the food chains here; a
large fraction of the energy available for consumers is brought
from the land; e.g., in falling leaves.
Rivers and Streams: Organisms need adaptations so that they
are not swept away by moving water; heavily affected by man
changing the course of flow (E.g. dams and channelstraightening) and by using rivers to dispose of waste.
Saltwater Communities
Estuary: Place where freshwater stream or river
merges with the ocean. Highly productive biome;
important for fisheries and feeding places for water
fowl. Often heavily polluted from river input so many
fisheries are now lost.
Ocean Zones
Marine environment with zonation.
Ocean Zones
Ecologists classify ocean
habitats and their organisms
on the basis of:1) water depth determines
pelagic zone includes neritic
zone and oceanic zone,
2) type of bottom determines
intertidal, continental shelf
and abyssal zones
3) and light level determines
photic and aphotic zones.
Intertidal Zone:
Alternately
submerged and
exposed by daily
cycle of tides.
Often polluted by
oil that decreases
biodiversity.
Coral Reefs: occur in
neritic zones of warm,
tropical water,
dominated by
cnidarians (corals);
very productive,
protect land from
storms; most are now
dying from rise in
global temperatures
Deep-sea vent: Occurs in benthic zone; diverse,
unusual organisms; energy comes not from light
but from chemicals released from the magma.
Biomes Summary
Biomes
•
•
1.
2.
biome
A _______
is a
large group of
ecosystems that
share the same
kind of climax
community.
There are 2
Types of
Terrestrial
Biomes:
Aquatic
Terrestrial Biomes
Terrestrial biomes are biomes located onland
_____.
• All Terrestrial Biomes are based upon the
various types of Climate Patterns.
• There are 6 Types of Terrestrial Biomes:
Tundra
1.
Taiga
2. Desert
3. Grassland
4.
Deciduous Forest
5. Tropical Rainforest
6.
Aquatic Biomes
•
•
•
1.
2.
3.
Aquatic Biomes are those biomes located in
water
bodies of ______.
All Aquatic Biomes are based upon the salinity
(saltiness) of the water. Also, the aquatic biomes
takes up the most space on Earth.
There are 3 Kinds of Aquatic Biomes:
Marine: High Salinity Level (Saltwater)
Estuary: Moderated Salinity Level (Mildly Salty)
Freshwater: Little to No Salinity Levels at all
Tundra
• Tundra environments
cold
have extremely _____
weather.
• The greatest precipitation
snow
is _____.
• Most animals respond to
this environment by
growing thick fur and
the plants remain small
(dwarf).
permafrost
• The soil is __________,
which is a layer of
permanently frozen
Taiga
• Taiga environments
consist of long
winters _______ &
severe
summers
short,
dry ________.
• Most animals adapt
migrating
by _________ when
it is cold, coming
back when it is
warm.
• There are many
adaptable trees such
Desert
• Desert environments
hot
dry
are ____
& ____.
• Animals adapt to this
environment by
constantly conserving
water
(saving) ______
when
it is needed for them
most.
• Animals are usually
nocturnal. Nocturnal
day
animals are thosenight
that
sleep during the ____,
and come out at _____
Grassland
• Grasslands
environments
wet &
experience a ____
dry season.
____
• Many animals in this
grazing animals.
are _______
Grazing
________
animals
are those that feed
upon plants, grass,
etc.
rich
• The soil in this area
is _____.
Deciduous Forest
• Deciduous Forest
environments have an
precipitation
abundant level of
_________.
seasons
• They also have 4 distinct
______.
winter
• Trees usually lose their
leaves in the ______.
• This is also the Biome
where WE LIVE!
Tropical Rainforest
• Tropical Rain Forest
environment is the
warmest & _______
wettest
_______
of
all biomes.
• It is found in areas near
equator
the ________.
• Most life severely
depends upon the
sunlight
_______ available.
• The forest area is
characterized
by
layers