Transcript Energy Flow in an Ecosystem

Unit 8: Ecology
ECOLOGY
BIODIVERSITY
Climate zones determine communities
Figure 5-2
Terrestrial biomes
Figure 5-9
Nonliving and Living Components
of Ecosystems
Populations & Communities
Ecological niche
 An organism’s role in its community
 Includes
 what it needs to survive
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Nutrients
Light
Space (habitat)
Oxygen or carbon dioxide
Inorganic compounds
 How it interacts with other species
Species interactions
 When two organisms interact together in one of
several ways.
 Can be intraspecific or interspecific
 One interaction is competition
What is the graph telling
us about the effect of
competition on species A
and B?
Predation is another (interspecific) interaction
 Predators adaptations
 Locate, sneak up on & subdue prey
 Prey adaptations
 elude & defend
horns, speed, coloration
spines, thorns, toxins
More Interspecific interactions
 Symbiotic interactions
 parasitism (-/+)
 mutualism (+/+)
 lichens (algae & fungus)
 commensalism (+/0)
 barnacles attached
to whale
Symbiosis
mutualism
commensalism
+/+
+/0
+/-/predation
+/- parasitism and competition
Two Necessities for Survival:
Energy Flow and Matter Recycling
Producers: Basic Source of All Food
 Most producers capture sunlight to produce
carbohydrates by photosynthesis:
This process of turning inorganic materials into
organic materials using energy from the sun is
called primary production.
Respiration: Getting Energy for Survival
 Organisms break down carbohydrates and other
organic compounds in their cells to obtain the
energy for internal reactions.
 This is done through aerobic respiration or
anaerobic respiration.
Consumers: Eating and
Recycling to Survive
 Consumers get their food by eating or
breaking down all or parts of other organisms
or their remains.
 Herbivores
 Carnivores
 Omnivores
Decomposers and Detritivores
Energy Flow
 Energy flows through an ecosystem
 Route of energy flow is determined by an
ecosystem’s trophic structure.
 Trophic interactions move energy through an
ecosystem
Simple example:
Food
Webs
 Trophic levels are
interconnected within a
more complicated food
web.
Energy Flow in an Ecosystem: Losing
Useful Energy in Food Chains and Webs
MATTER CYCLING IN
ECOSYSTEMS
 Nutrient Cycles: Global Recycling
 recycle nutrients through the earth’s air, land,
water, and living organisms.
 nutrients are the elements and compounds that
organisms need to live, grow, and reproduce.
 Carbon, nitrogen, phosphorus, sulfur, oxygen
 biogeochemical cycles move these substances
through air, water, soil, rock and living organisms.
Nutrient cycling
 All organisms are made up of organic molecules
 Carbohydrates
 Proteins
 Lipids
 Nucleic acids
 Essential nutrients are those that are required to make the
organic molecules
 C, H, N, O, P, S
 Organic matter cycles within ecosystems
 Both autotrophs and decomposers play vital roles
Carbon Cycle:
The Nitrogen Cycle:
Bacteria in Action
Phosphorus cycle