Transcript Livenv_ecology - OurTeachersPage.com

The Living Environment
The study of organisms and their
interactions with the environment.
Topics
• Unit 1:
• Unit 2:
• Unit 3:
• Unit 4:
• Unit 5:
Ecology
The Cell
Genetics
History of Biological Diversity
The Human Body
Unit 1: Ecology
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Principles of Ecology
Communities, Biomes, and Ecosystems
Population Ecology
Biodiversity and Conservation
Ecology
 The study of living organisms and their
interaction with the environment.
Biosphere
 The portion of Earth that supports life.
Ecosystem
 a biological community and all of the abiotic
factors that affect it.
Biotic Factors
(Living)
 Animals
 Plants
 Decomposers
 Single-celled organisms
Abiotic Factors
(Non-living)
 Sunlight
 Water
 Soil
 Air
How can we tell if something is
living, dead, or non-living?
Living things are currently alive. For
example, a frog, dog, or tree.
 Dead things were once living but are not
living anymore. For example, a dead frog,
dead dog, or dead tree.
 Non-living things were NEVER living. For
example, water, soil, sunlight, or air.

Life Functions
Respirate – use oxygen to make energy
 Reproduction – maintain the species
 To obtain and use energy
 Grow and develop

Population
 A group of the same species living together in
the same geographic area.
Community
 A group of interacting populations that occupy
the same geographic area.
Biome
 A large group of
ecosystems that
share the same
climate and have
similar types of
communities.
BIOMES
 Tundra
 Forest
 Grasslands
 Mountains
 Polar Region
 Rainforest
 Desert
How do we organize levels of
ecology?
Individual organism
Population
Community
Ecosystem
Biome
Biosphere
Ecosystem Interactions
Habitat: An area where an organism lives.
Niche: The role or position an organism
has in its environment.
How an organism meets its needs
for food, shelter, and reproduction.
Community Interactions
 Competition:
 When more than one organism uses a resource
at the same time.
Examples of resources:
Food
Water
Space
Light
Mate
Competition
Community Interactions
 Predation:
The act of one organism hunting and
killing another organism for food.
• The organism pursuing another organism is
the predator.
• The organism being pursued is the prey.
Predation
Symbiotic Relationships
 Symbiosis: Relationship between two or
more different species.
 Types of Relationships:
Mutualism
Commensalism
Parasitism
Mutualism
+/+
 Relationship
between two different
species that benefit
from each other.
Commensalism +/0
 Relationship in which
one organism
benefits and the
other is neither
helped nor harmed.
Parasitism +/ Relationship in which
one organism
benefits at the
expense of the other
organism.
Energy In An Ecosystem
How do organisms in a ecosystem get their
energy?

Autotrophs
Collect energy from sunlight and turn it into food.
Autotrophs are known as producers because they
can produce their own food.

Heterotrophs
Collect energy by consuming other organisms.
Heterotrophs are known as consumers because
they must consume other organisms to obtain
energy. They can NOT make their own food.
Autotrophs are producers.
 Examples are:
 Bacteria
 Grass
 Trees
 Algae
 All other
photosynthetic
organisms
Heterotrophs are consumers.
 There are four types of Heterotrophs:
Herbivores – consume only producers
Carnivores – consume only consumers
Omnivores – consume both producers
and consumers
Detritivores – consume dead matter and
waste materials
Herbivores
 Consume only
producers.
 They are plant
eaters.
Examples are:
 Horses
 Cows
 Rabbits
 Giraffes
Carnivores
 Consume only other
consumers.
 They do not eat any
plant material.
Examples are:
 Snakes
 Lions
 Owls
 Fox
Omnivores
 Consume both
producers and other
consumers.
 They will eat plant
material and meat.
Examples are:
 Bears
 Turtles
 Humans
 Lizards
Detritivores
 Consume fragments
of dead matter and
waste materials.
 Help return nutrients
to the soil, air, and
water to be reused
by organisms.
Models of Energy Flow
 Trophic Levels: Different levels of
nourishment in a food chain or food web.
 Food Chain: a simple model that shows
how energy flows through an ecosystem.
 Always start with a producer.
 Arrows represent the direction of energy
flow.
Food Chain
 Although it is never
drawn into a food
chain or food web,
what is the original
source of energy?
 THE SUN
Food Web
 A food web is a
model representing
the many ways in
which energy flows
through a group of
organisms.
 What do the arrows
represent?
Energy Pyramid
 In an energy
pyramid, each level
represents the
amount of energy
that is available to
that trophic level.
 With each step up,
there is an energy
loss of about 90%.
Numbers Pyramid
 In a pyramid of
numbers, each level
represents the
number of individual
organisms consumed
by the level above it.
Stability in Ecosystem
 The presence of necessary abiotic
factors including sunlight, water, space,
air, etc.
 The presence of all trophic levels
including, producers, primary consumers,
secondary consumers, and detritivores.
 Must have more producers than any
other group.
 Must have enough decomposers to
recycle nutrients.
Cycles in the Biosphere
 The Water Cycle
 The Carbon and Oxygen Cycles
 The Nitrogen Cycle
 The Phosphorus Cycle
The Water Cycle
• All living organisms need fresh water, but only about 3%
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of the water on Earth is fresh. 69% of that fresh water
is unavailable because it is locked up in glaciers and the
polar ice caps.
Water evaporates into the atmosphere from the ocean
as well as from the surface of plant leaves through a
process called transpiration.
This evaporated water becomes fresh water through the
evaporation process and eventually precipitates back to
Earth.
Some of this precipitated water runs off to the ocean,
while some is captured by lakes and rivers, and some is
percolated in the soil to become groundwater.
The Water Cycle
The Carbon and Oxygen Cycle
 Carbon and oxygen are necessary elements that
help support life. Carbon is used in every
organic molecule including those that make up
cells. Oxygen is a necessary element used by
cells to produce energy.
 During photosynthesis, green plants and algae
convert carbon-dioxide and water into energy
and return oxygen back into the atmosphere.
 This oxygen is used by autotrophs and
heterotrophs who then release carbon-dioxide
into the atmosphere during cellular respiration.
The Carbon and Oxygen
Cycles
The Nitrogen Cycle
 Nitrogen is a key element in the development of proteins
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which are imperative to life.
The most abundant gas in the atmosphere is nitrogen.
Plants and animals cannot use nitrogen directly from the
air. Bacteria that live in water, soil, and on plant root tips
convert atmospheric nitrogen into another form of
nitrogen that can be used by plants and animals. This is
known as nitrogen fixation.
Nitrogen is returned to the soil whenever an animal
urinates or when plants and animals die. Decomposers
return the leftover nitrogen in the dead organic material
into ammonia which is then turned back into usable
nitrogen by other organisms in the soil.
Some soil bacteria convert fixed nitrogen into nitrogen
gas through a process called denitrification which returns
to the atmosphere.
The Nitrogen Cycle
The Phosphorus Cycle
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Phosphorus is an element that is essential
for the growth and development of
organisms.
In the short term cycle, phosphorus is
transferred from producers to consumers
and then eventually returned to the soil by
decomposers.
In the long term cycle, weathering and
erosion of rocks that contain phosphorus
slowly adds phosphorus to the cycle.
The Phosphorus Cycle
How are population sizes limited by their
environment?

Limiting Factors:
• Sunlight
• Climate
• Temperature
• Water
• Nutrients (Food)
• Fire
• Soil
• Space
• Other living organisms –
Competition/Predation
Range of Tolerance
 Tolerance is the ability to
survive any particular
limiting factor.
 The diagram to the right
shows a plant’s
tolerance to a range of
temperatures.
 At optimal temperature,
the plant will grow the
tallest. Once outside the
range of tolerance, the
plant will not survive.
Carrying Capacity
 The carrying capacity
of an environment is
the largest number of
an individual species
that can be
supported.
 What factors affect
the carrying capacity
of a particular
environment?
Ecological Succession
 Primary Succession: the establishment of a
community in an area of exposed rock.
 The first organisms to appear on the rock are lichens and
mosses. These are known as pioneer organisms.
 They are followed by small plants and eventually trees.
Ecological Succession
 Climax Community:
stable, mature
community that
results when there is
little or no change
Ecological Succession
 Secondary Succession: the change that takes
place after a community of organisms has
been removed but the soil has remained intact.
What are the causes of ecological
succession?
Forest fire
 Volcanic eruption
 Tsunamis
 Hurricanes
 Tornadoes
 Flooding
 Landslides/Mudslides
 Earthquakes
 Glaciers receding

Terrestrial Biomes
 Weather vs. Climate
Weather is the condition of the atmosphere at a
specific place and time.
Climate consists of the average weather
conditions in an area including temperature
ranges and the amount and type of precipitation.
Major Land Biomes
 Tundra: treeless with a permanently frozen soil
layer called the permafrost.
 Boreal Forest: aka coniferous forest or taiga.
 Summers are longer than in the tundra so there is no
permafrost layer but with long, cold winters this is still a
very cold biome.
 Temperate Forest: aka Deciduous Forest
 Known for its beautiful fall colors due to the lack of evergreens and
more oak, beech, and maple trees.
 Also known for having all four seasons.
 Temperate woodland and shrubland
 This biome is aka chaparral. They typically contain
evergreen shrubs and receive less rainfall than
temperate forest.
 Temperate grassland: aka praire
 Characterized by fertile soil, grasses, and
grazing animals.
Desert: exist on every continent except Europe
 Any area where the rate of evaporation exceeds the
rate of precipitation.
 Surprisingly contain a wide variety of flora and fauna.
Tropical savanna
 Characterized by grasses and scattered trees.
 Tropical Seasonal Forest: aka tropical
dry forests
 Tropical Rain Forest
 Characterized by
warm
temperatures and
large amounts of
rainfall.
 Contain the most
diverse grouping
of organisms
compared to all
other land
biomes.
Biomes of the World
Aquatic Ecosystems
Freshwater Ecosystems
 Freshwater
ecosystems include
rivers, streams,
lakes, and ponds.
 Only about 2.5% of
the water on Earth is
freshwater and only
about 0.3% of the
water on Earth is
found in these
ecosystems.
Where is the other 2.2% of the
freshwater?

1.52% is frozen in glaciers

0.68% is groundwater
Rivers and Streams
 Water in these
ecosystems is constantly
in motion in one
direction.
 Areas of slow moving
water can sustain
benthic plant life as well
as insect larvae and fish.
Crabs, worms, newts,
tadpoles, and frogs may
also be found.
Lakes and Ponds
 There are 3 major
zones in freshwater
lakes and ponds; littoral
zone, limnetic zone,
and profundal zone.
 The littoral zone is the
shallow area close to
the shore.
 The limnetic zone is the
open water photic zone.
 The profundal zone is
the deeper aphotic
zone.
Transitional Aquatic Ecosystems
 Transitional aquatic
ecosystems are
areas where
freshwater mixes
with saltwater.
 These ecosystems
include wetlands and
estuaries.
Marine Ecosystems
 Include the intertidal
zone, open ocean
zone, and coastal
ocean and coral reef
zones.
 These are saltwater
ecosystems.
Intertidal Zone
 The intertidal zone is the
area along the shoreline
where the ocean meets
land.
 This area is divided into
smaller zones
dependant on how long
the area is underwater.
 These zones include the
low tide zone, middle
tide zone, high tide zone,
and spray zone.
Open Ocean Ecosystem
 The open ocean is divided
into 4 major zones:
 The photic zone is the upper
portion that receives plenty of
sunlight to sustain
photosynthetic organisms
 The aphotic zone that is
deeper and does not receive
any sunlight.
 The benthic zone which is the
area along the sea floor.
 The abyssal zone which is the
deepest region of the ocean.
Coral Reef Zone
 The coral reef zone is
the equivalent of an
underwater rainforest in
biodiversity.
 They are very delicate
and are largely studied
and protected by
governments all over the
world.
Aquatic Biomes