Download Principles of Ecology

Principles of Ecology
Chapter 13
Ecologists Study Relationships
• Interactions and Interdependence
 Ecology –
• Biosphere Populations
Species –
Communities –
Ecologists Study Relationships
Ecologists Study Relationships
Ecologists Study Relationships
Communities are within the ecosystem (Ex. A reef in the ocean)
Ecosystem –
Ecologists Study Relationships
 Scientists often study species, populations, or communities in an ecosystem.
• Levels of Organization
Ecologists Study Relationships
Biome –
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Ecologists Study Relationships
Ecological Methods
Observing – first step
Long term studies more beneficial-ecological change takes time
Surveys
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Determining Population Size
 Catch and release
 Quadrat Sampling
Ecologists Study Relationships
Experimenting – used to test hypotheses
Can do in the field or lab
LabField-
Modeling – gain insight
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Ecologists Study Relationships
Biotic and Abiotic Factors
• Living and Non-living components
– Biotic – Abiotic -
• Biodiversity
Biotic and Abiotic Factors
– The assortment, or variety of living things
– Dependent on temperature, moisture
– Keystone Species –
Energy in Ecosystems
• Producers – organisms that make their own food
 Autotrophs –
Energy in Ecosystems
Energy from the sun
• Photosynthesis – Autotrophs use light energy to power chemical reactions that make
energy
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Life without light
Energy in Ecosystems
• Chemosynthesis –
– Bacteria deep in the ocean
• Consumers –
Energy in Ecosystems
 These are also referred to as heterotrophs
• Feeding Relationships
• Food Chains –
Food Chains and Food Webs
Types of heterotrophs
• Herbivores
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Food Chains and Food Webs
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Carnivores
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Omnivores
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Detritivores
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Decomposers
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• Specialist
Food Chains and Food Webs
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• Generalist
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Food Chains and Food Webs
Trophic Levels – Each step in a food chain or web
• First level is __________________________________
• Second level on is consumers-usually herbivores
• Tertiary consumers are usually _________________________________
• Each consumer depends on the trophic level ___________________________ it
Food Chains and Food Webs
_________________________ – Feeding relationships among many organisms in an
ecosystem form a network of interactions
Cycling of Matter
• The ______________________Cycle (Water Cycle)
– _______________________ – Water changes from a liquid to a gas
– _________________________ – Evaporation from the leaves of a plant
Cycling of Matter
Clouds form from tiny drops of water collecting called condensation
• Recycling in the Biosphere
Cycling of Matter
Biogeochemical cycles
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– Energy moves in a one way fashion – Nutrients recycle
• Nutrient Cycles
Cycling of Matter
___________________________ – All the chemical substances that an organism
needs to sustain life
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Cycling of Matter
– Most organisms use oxygen need oxygen
– Plants release oxygen
– Living organisms release carbon dioxide as a waste product
Cycling of Matter
The Carbon Cycle
• ______________________ is passed on from one situation to another throughout the
biosphere
– Photosynthesis uses CO2 to make carbs
– Carbs are eaten by other organisms
– Organisms exhale CO2 during cellular respiration
– All organisms eventually decay and the carbon is converted to coal or petroleum
– Burning things releases stored CO2 into the atmosphere
Cycling of Matter
The Nitrogen Cycle
• All organisms need _______________________ to make amino acids
– What do amino acids make?
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– 78% of Earth’s atmosphere
 Nitrogen gas (N2)
– Other types:
– Ammonia (NH3)
 Nitrate (NO3)
 Nitrite (NO2)
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_____________________ – N2 to NH3
Denitrification - NO3 to N2
– The Phosphorus Cycle
Cycling of Matter
• ____________________________ need phosphorus
• This element does not go into the atmosphere
• Phosphorus works its way through the food web
• Nutrient Limitation
Cycling of Matter
– Ecologists look at the rate of production of producers –
– Availability of nutrients can limit an ecosystem
– Limiting nutrient
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– Nitrogen in the ocean is the limiting nutrient
• 0.00005% nitrogen
• If runoff causes a drastic increase in nitrogen, then an algae bloom occurs
Pyramid Models
• _____________________________ – diagram that shows how much energy is
transferred at each trophic level
Biomass Pyramid
Pyramid Models
• ______________________ – Total amount of living tissue in a level
– Represents the amount of potential food available at each trophic level
___________________________
Pyramid Models
• Only about _____________________ of the energy is transferred to the next trophic
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level
– More levels means less energy at the last level
Pyramid Models
Shows how many individuals there are in each level