Post on 23-Feb-2016
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Ecology
SNC1D
Why Study Ecology?
Sustainability:• The ability to
maintain an ecological balance
Ecology: The study of the interaction of living things with each other and with abiotic factors in their environment.
Abiotic Factors:e.g.
Biotic Factors:e.g.
• Ecology can begin at the level of a single organism
• But organisms do not live in isolation
Ecological LadderBiosphere
BiomeEcosystemCommunityPopulation
SpeciesOrganismIn
crea
sing
com
plex
ity
• Ecosystems rarely have sharp boundaries
• Organisms can move from one ecosystem to another
Ecotone: The transition area between two ecosystems
• Contains members of the community of both ecosystems
Ecotone
Biodiversity: The number and variety of species in an ecosystem
• Ecotones have ______ biodiversity.
• High biodiversity usually indicates a more sustainable ecosystem.
Terms To Define:• 7 terms on the ecological ladder• Herbivore, carnivore, omnivore• Habitat• Sustainable Ecosystem• Natural and Artificial
Ecosystems• Niche
Energy Flow in Ecosystems
The Sun• The source of all energy
• Light• Heat• Evaporation (for precipitation)• Photosynthesis
• _30__% of the total energy is reflected by clouds or Earth’s surface
• _44__% heats atmosphere, surfaces, • __25___% heats and evaporates water• ___1__ % wind• _0.023__% for photosynthesis
Biotic FactorsProducer Consumer
Alternate Name Autotroph Heterotroph
Energy Source
• Make (produce) their own food• From sunlight and basic nutrients (abiotic factors)
• CANNOT make their own food• Must obtain it from autotrophs or other heterotrophs (biotic factors)
Example Plants
HerbivoresOmnivoresCarnivores
Trophic Levels• Categorize living things
(biotic factors) according to how they gain their energy.
1st Trophic Level• Contains organisms that are able to make
their own food from abiotic factors (e.g. soil nutrients, sunlight)
• Organisms in the 1st trophic level are called producers______ or ___autotrophs___
• E.g.
2nd Trophic Level• Contains organisms that feed on producers• Rely DIRECTLY on producers for their source
of energy.• Organisms in the 2nd trophic level are called
herbivores/ primary consumers/ heterotrophs_
• E.g.
3rd Trophic Level• Contains organisms that rely on primary
consumers as their main energy source• But, indirectly, are still dependent on
producers• Organisms in the 3rd trophic level are called
__secondary consumers______________• E.g.
Decomposers• Organisms that feed on detritus
Detritus: Waste from biotic factors, including their dead remain
• Return nutrients (abiotic factors) to the ecosystem
• E.g.
1st Trophic Levels
2nd Trophic Levels
3rd Trophic Levels
4th Trophic Levels
1st Trophic Levels
2nd Trophic Levels
3rd Trophic Levels
4th Trophic Levels
Food Chains• Step-by-step sequence
linking organisms that feed on each other
• Arrows show the flow of energy (“is eaten by”)
• Do not exist in nature• Show simple feeding
relationships
Food Webs
• In reality, each organism has a variety of food sources and is therefore involved in multiple food chains
• These food chains interlock to form a complex food web
Food Web: Representation of the complex feeding relationships in an ecosystem
Energy Flow• Organisms use about 90 % of the
energy they take in to grow and reproduce, leaving just 10% of the energy they receive to pass along to the next trophic level.
grass → grasshopper → frog → snake → hawk
Ecological Pyramids• Are used to organize the information of these
transfers, and the most common are:Type Pyramid of
numbersPyramid of Biomass
Pyramid of Energy
Based on… Population of Organisms
Mass of Organisms
Stored energy in organisms
Drawing