1. Chapter 3 – The Biosphere

2. 3.1 Ecologists study environments
at different levels of organization.
Ecology is the study of the interactions among living
things, and between living things and their surroundings.

3. Organism
Population
Community
Ecosystem

4. Biotic and Abiotic Factors
 Biotic factors are any living part of an environment.
 plants
 animals
 fungi
 bacteria

5.  Abiotic factors are any nonliving part of the
environment.
 Sunlight
 Temperature
 Precipitation
 Humidity
 Wind

6. Biotic and Abiotic Factors
Together
 Physical factors can be strongly influenced by the
activities of organisms.
 Also, a change in physical factors can strongly affect the
survival of the living organisms.

7. 3.2 Energy in Ecosystems
 Living organisms need energy for
growth, reproduction, and their metabolic processes.
 Producers provide all of the available energy in an
ecosystem
 Primary Productivity
 Producers are also called autotrophs because they
make their own food.
 Most producers uses sunlight as an energy source.

9.  Heterotrophs acquire energy from other organisms.
 Also called consumers

10.  Consumers are not all alike.
 Herbivores eat plants.
 Carnivores eat other animals.
 Omnivores eat both plants and animals.
 Detritivores eat dead organic matter (detritus).
 Decomposers break down organic matter into
simpler compounds.
carnivore
decomposer

11. 3.3 Energy Flow in Ecosystems
 A food chain links species by their feeding
relationships.
 A food chain follows the connection between one
producer and a single chain of consumers within an
ecosystem.
 The ultimate source of energy for all producers and
consumers is the sun.

12. Trophic Levels
 First Level – Producers
 Determine the available energy in the ecosystem
 Second Level – First Level Consumers
 AKA – primary consumers
 Herbivores
 Third Level – Second Level Consumers
 AKA – secondary consumers
 Omnivores and carnivores

13.  Fourth Level
 Third level consumers
(carnivores that eat other
carnivores)
 AKA - top carnivores or
tertiary consumers
 Decomposers – obtain energy
from dead and decaying matter at
all trophic levels.
 produce detritus
 Ex: bacteria and fungi decomposer

14. Energy Flow
 An energy pyramid shows the
distribution of energy among
trophic levels.
 Only 10 percent of the
energy at each tier is
transferred from one
trophic level to the next.
 90 percent of the energy is
lost into the atmosphere as
heat.
energy transferred
energy
lost
100%
10%
1%
0.1%

15. Food Webs
 A food web shows a complex network of feeding
relationships.
 An organism may have multiple feeding
relationships in an ecosystem.
 A food web emphasizes complicated feeding
relationships and energy flow in an ecosystem.

17. Pyramid of Biomass
 Biomass is usually measured
in grams of organic matter
per unit area.
 Why does the amount of
biomass decrease moving up
the trophic levels?
tertiary
consumers
secondary
consumers
primary
consumers
producers
75 g/m2
150g/m2
675g/m2
2000g/m2producers 2000g/m2

18. 3.4 Cycles of Matter
 Elements essential for life cycle through ecosystems.
 A biogeochemical cycle is the movement of a
particular chemical through the living and non-
living parts of an ecosystem.
 Matter is recycled within and between ecosystems.
 Biogeochemical Cycles

19. Water Cycle

20. CarbonCycle

21. Nitrogen Cycle