Download Cause and Effect Relationships of the Ecological Systems

Cause and Effect
Relationships of the
Ecological Systems
Prepared by:
NOROLAIN D. GURO
MsiEd-Math
Key Concepts
• Ecology
• Energy Flow
• Ecosystem Diversity
• Natural Ecosystem Changes
Ecology
a science that deals
with the relationships
between groups of living
things
and
their
environments.
Biological Populations and
Communities
• Intraspecific – same species that
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•
interact with each other and
occupy a specific area creates
population
Interspecific – different species
living and interacting in same area
form community
Ecosystem – system formed by the
interelation of a community with
their environment.
Biosphere → ecosystem → communities
→ populations → species → organisms
Ecological Niches
An Ecological Niches is an area
with in a habitat and includes species use
of biotic (living) and abiotic (nonliving)
resources in the environment
Generalist – Live in broad
niches, can withstand a
wide range of
environmental conditions
Ex. Humans, mice, roaches
Specialist – live in
narrow niches, sensitive
to environmental changes
Ex. pandas
Keystones Species
• Keystone Species – species whose
•
presence contributes to the balance
and diversity of an ecosystem
Have large impact on how the
ecosystems function
Ex. Wolfs, Grizzly Bears, Sea Stars,
Prairie Dogs, Sea Otters
Biomes
Biomes are different kinds of
ecosystems (your text calls them
life zones), are associated with
different physical conditions, and
include
different
kinds
of
communities that have become
adapted
to
those
physical
conditions and each other.
Biomes
• Freshwater ecosystems are: ponds and lakes;
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streams and rivers and wetlands. Wetlands
include bogs, swamps and marshes and
contain the most species of any of the
planet's ecosystems.
Marine ecosystems are: oceans, coral
reefs and estuaries. The oceans are the
world's largest ecosystems and are
considered to cover the shore as far as tidal
waters come in.
Desert ecosystems are: hot and dry deserts,
semi-arid, coastal and cold. While we often
think of deserts and heats as synonymous,
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parts of the Arctic and Antarctic are classified as
deserts because of their low rainfall.
Forest ecosystems are: tropical, temperate and
boreal. Tropical forests include the great rainforests,
which, with their incredible diversity of species and
importance as carbon sinks are a focus for
environmentalists. Boreal forests, also called taiga,
are the largest biome on land.
Grasslands are: tropical (or savannas) and temperate.
Temperate grasslands include the great American
prairies and the Russian steppe.
Tundra ecosystems are: arctic and alpine.
Species Diversity
Organisms that live in different environments
are specifically adapted to their biome.
The main types are:
• Aquatic organism
• Desert Organism
• Grassland Organism
• Forest Organism
• Tundra Organisms
• Temperatures scrub forest land Organisms
Edge Effects
Edge Effects – How the local environment changes
along some type of boundary or edge.
An example is forest edge created when trees are
clear cut, some species survive well while other
animals do not do well in this edge.
Negative edge effects become most extreme when
forest meets suburbs.
Open community – edge effect is gradual or has
indistinct boundaries
Closed community – sharply divided from its
neighbours
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Energy Flow
Energy Flow
The ultimate source of energy is the sun
Photosynthesis – plants take in carbon dioxide,
water and light energy to make carbohydrates
and oxygen.
Cellular Respiration – opposite of
photosynthesis, glucose is oxidized by cells to
produce carbon dioxide, water, and chemical
energy.
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Food Webs and Trophic Levels
• Trophic Level – Each feeding in food chain
• Primary Producers (autotrophs) – plants that use
photosynthesis to create energy
• Primary Consumers (heterotrophs) – herbivores
(plant eaters), get energy by eating autotrophs.
• Secondary Consumers (heterotrophs) – Obtain
food energy by consuming other organisms,
carnivores (meat eaters) or omnivores (eats both
plants and animals)
Ecological Pyramids
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Ecological pyramids begin with producers on the
bottom (such as plants) and proceed through the various
trophic levels (such as herbivores that eat plants, then
carnivores that eat herbivores, then carnivores that eat
those carnivores and so on). The highest level is the top of
the food chain.
Sunlight is the ultimate source of energy
Potential energy is lost as you move up an energy
pyramid. This is like the second law of thermodynamics,
some energy is transferred to surroundings as heat as no
process can be 100% effective
An average of 90% energy loss as one moves to the next
higher trophic level
Ecosystem Diversity
Biodiversity
• Biodiversity describes diversity at 3 levels: genetic,
species and ecosystems
• Rain forest cover only 7% of land but hold over half
of all species, making it the most diverse biome
Diversity Increase
Diversity Degreasers
Diverse habitats
Environmental stress
Disturbance in habitat (fires, storms, etc.) Introduction of species from other areas
Environmental conditions with low
variation
Extreme limitations in the supply of a
fundamental resource
Trophic Levels with high diversity
Extreme amounts of disturbance
Middle states of succession
Extreme environment
Evolution
Geographic isolation
Natural Selection
Natural selection occurs by determining which traits
organism have that help survive, reproduce, and pass those
traits on. Natural selection leads to evolution, which describe
how species attain genetic traits allow them to survive in
changing environments.
Natural selection operates in three ways:
• Stabilizing
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•
– Most common, affects extremes of a
population individual too far average are removed, decrease
in diversity and no evolution
Directional – Affects only one side of the extreme
Disruptive – Acts against the average, favours individual at
the extreme ends, population changes, evolution occurs.
Evolution
• Evolution is the change in the genetic
•
•
composition of a population after generation as
a result of natural selection
Changes take a very long time and are
supported by fossil record
Concept of the “common ancestor”
Evolution
Speciation – result when segment of a population
become so isolated that gene flow stops. Adaptive
radiation describes this.
Convert evolution – process where organisms are not
closely related to each other but acquire similar
characteristics while in different ecosystems Ex. Wings
on bird and bats
Evolution Relay – when independent species acquire
similar characteristics from their evolution in similar
ecosystems but not at the same time.
Parallel Evolution – different species evolve together at
same time in same ecosystem acquire similar
characteristics
Gradualism – views evolution as slow, over millions of
years
Punctuated Equilibrium – some species arose suddenly
in short period of time (thousands of years) after long
periods of stability
Ecosystem Services
Ecosystem Services – processes by which the
environment produces resources, like clean
water, timber etc.
Ecosystems provide the following services:
Moderate weather extremes and their impacts
Disperse seeds, Generate and preserve soils
Mitigate droughts and floods
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• Cycle and move nutrients
• Protects river channels and coastal shores from
erosion
• Detoxify and decompose waste
• Control agricultural pests
• Maintain biodiversity
• Contribute to climate stability
• Purify the air and water
• Regulate disease-carrying organisms
• Pollinate crops and natural vegetation
Natural Ecosystem
Changes
Climate Shifts
Earth’s climate has gone through many cycles of
warming and cooling trends
Factors that influence the climate:
Albedo – reflectivity, the highest albedo is snow, ice
and dust in atmosphere. High albedo cause cooling
Carbon cycle – production of carbon dioxide (CO2)
results in warming
Greenhouse effect – water, carbon dioxide, and
methane, keeps earth warm but taken to far can over
heat it
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• Landmass distribution – materials absorb and
reflect solar radiation to different extents
• Plate tectonics and Volcanoes – plates effects
atmospheric CO and Volcanoes produces CO
• Precession – the wobble of Earth on its axis
and changes to its orientation in effect climate
• Solar output – can change Earth’s temperature.
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Species Movements
• Movement is important for many organisms,
•
like birds flying large distances or plant seeds
being moved by wind
Organisms move to new habitats in order to
reduce intraspecific competition
Ecological Succession
Ecological Succession – the gradual and orderly
process of ecosystems development, describing
changes in an ecosystem through time and
disturbance.
Types of Succession:
Allogenic
Primary
Progressive
Retrogressive
Secondary
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References
• Ecology. http://www.merriamwebster.com/dictionary/ecology
• Ecology.
http://www.csus.edu/indiv/l/loom/lect%203132%20s07.htm
• AP Environmental Science Review:
Ecological Systems.
http://youtu.be/FdQVW1oTRG0