• Ecology – the study of the interactions between organisms and the living and nonliving components of their environment.

• Levels of Organization
– Biosphere
– Ecosystem
– Community
– Population
– Organism

• Organism – an individual living thing
• Species – a group of organisms that can mate to produce fertile offspring

• Population – all the members of the same species that live in the same place at the same time
– Members of a population generally breed with one another rather than members of other populations

• Community – a group of various species that live in the same place and interact with each other
– Only made up of BIOTIC components

• Ecosystem – all of the organisms living in an area together with their physical environment
– Ex. An oak forest, a coral reef, a mangrove swamp

• Biosphere – the thin volume of Earth and its atmosphere that supports life.

• Biotic factors – the living and once living parts of an ecosystem
– Plants and animals
– Dead organisms
• Abiotic factors – nonliving parts of an ecosystem
– Air
– Water
– Rocks
– Light
– Temperature

1.
What is taxonomy? Why bother to classify organisms?
2.
What is the purpose of a scientific name?
3.
What two taxa make up an organisms scientific name? How is this scientific name correctly written?
4.
Write these scientific names correctly:
– mola mola
– homo sapians
– tyrannosaurus rex
5.
What are the different taxonomic groups? What is the broadest, most inclusive? What is the smallest and most specific?
6.
What is ecology?
7.
What are the levels of organization in ecology from smallest to largest?
8.
What is the difference between an ecosystem and a community?
9.
What are biotic and abiotic factors?

• Habitat – the place an organism lives
• Habitats have everything (biotic and abiotic) that the organism needs to survive
• Organisms are well suited for their habitats
• Very specific biotic and abiotic conditions

• Tolerance curve – a graph of performance vs. values of an environmental variable

• Acclimation – some organisms can adjust their tolerance to abiotic factors
– Example – Goldfish
• Organisms deal with changes in their environment in one of two ways:
1. Conformers – do not regulate their internal conditions, change as the environment changes
2. Regulators – use energy to control some of their internal conditions to keep them in an optimal range

• What happens when conditions are unfavorable?
– Migration – movement to a more favorable habitat
– Dormancy – a state of reduced activity during a period of unfavorable conditions

• Niche – the specific role or way of life of a species within its environment
– Often thought of as its “job” or what it does
• Generalist species – have a broad niche; can tolerate a wide range of conditions and use a variety of resources
• Specialist species – have a very narrow niche; have very specific dietary requirements, live in only specific conditions

• What are the main levels of organization in ecology? How do they differ?
• What are biotic and abiotic ecosystem components?
• What is a habitat? What is a niche? How do they differ?
• What is a tolerance curve?

• Producer – an organism that makes its own food
– Also called autotrophs
– Example: Plants
• Consumers – organisms that get their energy by eating other organisms
– Also called heterotrophs
– Example: Rabbits, Cows, Deer, Wolves

• Herbivores – plant eaters
• Carnivores – meat eaters
• Omnivores – eat both plants and meat
• Detritivores/decomposers - get their food by breaking down dead organisms

• Production - the synthesis and storage of organic molecules during the growth and reproduction of photosynthetic organisms
• Gross primary productivity (GPP) – the rate at which producers in an ecosystem capture the energy of sunlight by producing organic compounds
– (think photosynthesis)
• Biomass – the organic material that has been produced in an ecosystem. Producers (plants) making organic molecules (like glucose!)
• Net primary productivity (NPP) – the rate at which biomass accumulates in an ecosystem.
– NPP = GPP - respiration

• A linear sequence in which energy is transferred from one organism to the next as each organism eats another organism

• Shows many feeding relationships that are possible in an ecosystem.
• Much more complex than a food chain

• Trophic level - each step in the transfer of energy through a food chain or food web in an ecosystem
• Energy is lost each time energy is transferred from one organism to another

• Only 10% of the energy is transferred from one trophic level to the next.
• For every 1,000 producers, 1 tertiary consumer

• How does energy transfer through an ecosystem. Explain the number of higher level consumers that can be present?
• What are autotrophs? Heterotrophs?
• What is the difference between a food chain and a food web?
• What is productivity?

• Biogeochemical cycles – the circulation of substances through living organisms from or to the environment
– Water Cycle
– Carbon Cycle
– Nitrogen Cycle
– Phosphorus Cycle

• The water cycle involves
– Evaporation
– Condensation
– Precipitation
– Transpiration – the process by which water evaporates from the leaves of plants in terrestrial ecosystems

• The process by which carbon is cycled between the atmosphere, land, water, and organisms.

• Link between photosynthesis in producers and respiration in producers, consumers, and decomposers
• Movement of carbon from the nonliving environment to living things and back.

• Plants take in CO
2 from the atmosphere through photosynthesis
• Animals eat plants
• Animals release CO
2 through respiration
• Some carbon may be converted into carbonates, which make up the hard parts of bones and shells
– Deposit into carbon sinks
– Over time, these become fossil fuels

• Nitrogen cycle - process in which nitrogen is cycled between the atmosphere, bacteria, and other organisms.
• Nitrogen makes up 78% of atmosphere
– Not in a form most organisms can use
• Nitrogen fixing bacteria - fix atmospheric nitrogen into chemical compounds that organisms can use

• Nitrogen-fixing bacteria live within nodules on the roots of plants called legumes
– beans, peas, and clover
• Plants that do not have nitrogen-fixing bacteria in their roots get nitrogen from the soil.
• Animals get nitrogen by eating plants or other animals.

• Decomposers break down wastes and return the nitrogen that these wastes and dead organisms contain to the soil in a process called ammonification.
• Nitrification – the process by which soil bacteria uptake ammonium and form it into nitrites
• Denitrification – occurs when anaerobic bacteria break down nitrates and release nitrogen gas into the atmosphere.

• Phosphorus cycle – the movement of phosphorus from the environment to organisms and then back to the environment
• Very slow cycle
• No atmospheric component (Carbon and
Nitrogen cycles do)

• Rocks erode
• Phosphate dissolves in water
• Plants absorb phosphate through roots
• Excreted when organisms decompose

• Summarize the carbon cycle.
• Summarize the nitrogen cycle
• Summarize the phosphorus cycle.
• How do humans have the potential to impact each of these cycles?
• Which is the only cycle without an atmospheric component?