Chapters

1
Ecology
Chapters
3-5
2
31 What Is Ecology?
3
Intro/ General Terms

• Ecology the study of interactions among
  organisms and between organisms and their
  environment
• Biosphere part of Earth in which life exists
• including land, water, and air
• extends from 8 kilometers above to 11 kilometers
  below Earths surface
• Interactions within the biosphere produce a web
  of interdependence between organisms and the
  environment in which they live. Miller
  Levine

4
Levels of Organization

• Population group of individuals that belong to
  the same species and live in the same area
• Community all the different populations that
  live together in a defined area
• Ecosystem collection of all the organisms that
  live in a particular place, together with their
  nonliving, or physical environment
• Biome group of ecosystems that have the same
  climate and dominant communities
• Biosphere

SMALLEST
LARGEST
5
(No Transcript)
6
32 Energy Flow
7
Energy

• Energy the ability to do work
• Sunlight is the main source of energy for all
  life on Earth.

8
Producers

• Autotroph organism that captures energy and
  uses it to produce its own food from inorganic
  compounds
• Producers capture energy from different sources
• Sunlight organisms use light energy to produce
  food during photosynthesis
• ex plants, some protists, some eubacteria
• Chemicals organisms use chemical energy to
  produce food during chemosynthesis
• ex some archaebacteria

9
Consumers

• Heterotroph organism that relies on other
  organisms for energy and food
• Consumers obtain food and energy in different
  ways
• Herbivores eat only plants
• Ex cows, caterpillars, deer
• Carnivores eat only animals
• Ex snakes, owls, tigers
• Omnivores eat both plants and animals
• Ex humans, bears, crows
• Detritivores eat plant and animal remains
• Ex earthworms, vultures, crabs
• Decomposers break down organic matter
• Ex bacteria, fungi

10
Feeding Relationships

• Energy flows through an ecosystem in ONLY ONE
  direction.

Sun (or inorganic compounds)
Producers
Consumers
11
Food Chains

• Food Chain a series of steps in which organisms
  transfer energy by eating and being eaten
• Example
• NOTICE arrows always point in the direction
  of the energy flow (movement of glucose)

12
Food Webs

• Most ecosystems have more complex feeding
  relationships than a simple food chain.
• Food Web complex network of all of the energy
  flow and feeding relationships in an ecosystem /
  several food chains linked together
• Trophic Levels
• Each step in a food chain or web
• Producers make up the 1st trophic level
• Consumers make up the 2nd, 3rd etc.
• Each consumer depends on the trophic level below
  it for energy

13

• Using the food web below, write out 4 different
  food chains that can be seen.

14
Energy Pyramid

• Shows the amount of energy available in each
  trophic level of a food chain.
• Only 10 of the energy available within a trophic
  level is passed on to the next trophic level.
• The rest of the energy is used by the organism or
  lost as heat.

15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
3-3 Cycles of Matter
21
Recycling in the Biosphere

• Organisms need important elements and compounds
  such as water, carbon, and nitrogen.
• Organisms can only use these required elements
  if they are in a certain chemical form.
• There is also a finite amount of these elements
  and compounds.
• Biogeochemical cycles elements and compounds
  are passed (recycled) between the biological
  geological, and chemical parts of the biosphere

22
Biogeochemical Cycles

• Chemical cycles typically involve 3 general
  steps
• Producers change inorganic matter from the
  nonliving environment into organic compounds.
• Consumers eat producers, incorporating some of
  the organic matter into their own bodies. They
  also release inorganic compounds back to the
  environment as waste.
• Decomposers break down organic matter into
  inorganic compounds and release them back into
  the environment.
• (The cycle begins again at step 1.)
• Part of each cycle also involves nonliving
  processes that move chemicals around ecosystems.

23
(evaporation from plants)
Water Cycle
24
The Water Cycle

• Evaporation - Liquid water turning to water
  vapor, moving from ground to air
• Transpiration - Water evaporation from within
  plants
• Precipitation - Water vapor returning to ground
  as rain/snow

25
Carbon Cycle
26
The Carbon Cycle

• Fossil fuels - Organisms decomposing for a long
  time become oil, gas, coal
• Combustion - Burning

27
Nitrogen Cycle
28
The Nitrogen Cycle

• Nitrogen fixation - Converting nitrogen in the
  air into liquid/solid forms that living things
  can use
• Legume plant - Plants able to fix atmospheric
  nitrogen, thanks to bacteria in their roots
• Denitrification - liquid/solid nitrogen converted
  into atmospheric nitrogen by bacteria

29
Section 4-2What Shapes an Ecosystem?
30
Biotic versus Abiotic Factors

• Biotic factor a factor that has a biological
  influence on organisms within an ecosystem
• Abiotic factor a physical, or nonliving, factor
  that shapes an ecosystem
• Together, biotic and abiotic factors determine
  the survival and growth of an organism and the
  productivity of the ecosystem in which the
  organism lives.

31
Describing an Ecosystem

• Habitat area where an organism lives
• Niche full range of physical and biological
  conditions in which an organism lives and the way
  in which the organism uses those conditions

32
Community Interactions

• Community interactions can affect an ecosystem
• Competition - organisms of the same or different
  species trying to use an ecological resource in
  the same place at the same time
• Example Two birds attempting to eat the same
  worm.
• Predation - one organism capturing and feeding on
  another organism
• Example A lion catching and eating an antelope.
• Symbiosis - two species living closely together
• 3 Types mutualism, commensalism, parasitism

33

• Mutualism both species benefit from the
  relationship
• Example The ant cares for the aphids and
  protects them from predators. The aphids produce
  a sweet liquid that the ant drinks.

34

• Commensalism one member of the association
  benefits and the other is neither helped nor
  harmed
• Example Barnacles attach themselves to whales.
  The barnacles do not harm or help the whales but
  they benefit from the constant movement of water
  carrying food particles to them.

35

• Parasitism one organism lives in or on another
  organism and harms it
• Example Fleas, ticks, and lice live on the
  bodies of mammals, feeding on the blood and skin
  of the host causing harm to the organism.

36
5-1 How Populations Grow
37
Populations

• Population a group of organisms of the same
  species that live in a particular place
• Important Characteristics
• Size
• Geographic Distribution
• Population
  Density
• Growth Rate

38
Population Characteristics

• Geographic Distribution - describes the area
  inhabited by the population (range)
• Population Density is the number of individuals
  per unit area (example 200 puffins per 100
  square feet.)

39
Population Growth

• Natural populations may stay a constant size,
  grow rapidly, or decrease rapidly.
• Factors that can change population size
• Number of births (increase population size)
• Number of deaths (decrease)
• Number of immigrations (increase)
• Number of emigrations (decrease)

40
Measuring Populations

• Growth Rate amount a population changes size in
  a given time
• Depends on births, deaths, emigration and
  immigration
• Growth Rate BI-DE (births immigration)
  (deaths emigration)

What happens to the growth rate if immigrations
go up?
What happens to the growth rate if emigrations go
up?
What happens to the growth rate if deaths
go down?
What happens to the growth rate if
immigrations go down?
What happens to the growth rate if births
go down?
It increases.
It decreases.
It increases.
It decreases.
It decreases.
41
Exponential Growth

• Exponential a population increases rapidly and
  the larger it gets, the faster it grows
• J-shaped curve
• occurs when resources are
  abundant
• Eventually populations will
  run out of some resource, the Limiting Factor.

42
Logistic Growth

• Logistic a populations growth slows or stops
  and population size levels off
• S-shaped curve
• occurs when
  resources are
  limited
• Populations grow
  to Carrying Capacity (K), the largest
  number the environment
  can support.

43
Limits to Growth

• Limiting Factor any biotic or abiotic factor
  that causes a population to decrease in size
• Density-Dependent Factor affects the population
  differently depending on the population size
• Examples competition, predation, parasitism, and
  disease
• Density-Independent Factor affects all
  populations in the same way, regardless of the
  population size
• Examples natural disasters, seasonal cycles,
  weather, and human activities