Chapter 2 Flashcards
Biomass
- The total mass of living plants, animals, fungi, and bacteria in a given area.
- The mass of a particular type of organic matter such as trees, plant crops, manures, and other organic materials that may be used to manufacture biofuels such a biogas.
Estimates of biomass are usually expressed in grams or kilograms per square metre.
Energy Flow
● The flow of energy from an ecosystem to an organism and from one organism to another
● Every organism plays two roles in energy flow:
1. Obtains food energy from ecosystem
2. Contributes energy to ecosystem
Producer
● Organisms that “produce” food in the form of carbohydrates during photosynthesis.
● Plants are an example of a producer.
● Carbohydrates stored in plants become an energy source for other life forms.
Consumer
● Organisms that consume other things (ie. producers, or other consumers) for energy. They do not produce their own food.
● An insect (ie. bee) that feeds on a plant (ie. sunflower) is an example of a consumer.
● A consumer may become an energy source if consumed by another consumer.
● There are different levels of consumers (ie. primary, secondary, tertiary, etc.)
Decomposition
● The breaking down of organic wastes and dead organisms
● Through this process, organisms continue to contribute to the energy flow in an ecosystem, even after their death.
Biodegradation
● The action of living organisms breaking down the organic wastes and dead organisms.
● Decomposition carried out by living organisms
Decomposers
● Organisms that change waste and dead organisms into usable nutrients. (ie. bacteria and fungi)
- These nutrients are then made available to other organisms in soil and water and link the biotic/abiotic components of an ecosystem.
List the different ways in which energy flow and feeding relationships are modelled.
- Food chains
- Food webs
- Food pyramids
Food chain
● Show the flow of energy from plant to animal and from animal to animal.
● Follows a single path as energy flows from one trophic level to the next in an ecosystem.
Trophic level
● Each step in a food chain is called a trophic level
● Primary producers are one the first trophic level.
- Primary consumers (organisms that consume these producers) would be the second trophic level, and so on.
● Only~10% of energy is transferred to the next trophic level
Primary consumer
● Consumers that consume producers
- ie. grasshoppers, deer, any herbivore
● Second trophic level
Secondary consumer
● Consumers that consume primary consumers
- ie. frogs, crabs, etc.
● Third trophic level
Tertiary consumer
● Consumers that consume secondary consumers
- ie. wolves, lions, hawks, etc.
Detritivores
● Consumers that obtain their energy and nutrients by eating the bodies of small dead animals, dead plant matter, and animal wastes.
● Feed at every trophic level
Herbivores
● Primary consumers that eat plants
● Examples include: bighorn sheep, western tiger swallowtail butterflies (pg. 61)
Carnivores
● Secondary/tertiary consumers
- Carnivores that eat secondary consumers are often referred to as top carnivores, top consumers, or top predators
● Eat other consumers
● Examples of carnivores include grey wolves and hobo spiders (pg. 62)
Omnivores
● Consumers that eat both plants and animals
● They are found on more than one trophic level
Food web
● Formed by interconnected food chains
● Models of the feeding relationships within an ecosystem
Food pyramid
● Shows the loss of energy from one trophic level to another
● Often referred to as ecological pyramids
What are the different types of ecological pyramids?
- Pyramid of biomass
- Pyramid of numbers
- Pyramid of energy
Pyramid of biomass (What is it? What are the limitations?)
● An ecological pyramid that shows the number of organisms at each trophic level multiplied by their mass, which compensates for differences in size among organisms
● Limitations:
- In some ecosystems, the biomass of lower trophic levels can be less than that of higher trophic levels.
(ie. in aquatic ecosystems, pyramids of biomass may be inverted because of the rapid reproduction rates of primary producers such as algae.)
Pyramid of numbers (What is it? What are the limitations?)
● An ecological pyramid that shows the number of organisms at each trophic level
● Limitations:
- The sizes of individual organisms vary greatly, and thus their energy needs vary greatly
- The range of numbers from the producers to the tertiary consumers may be so great that it is impossible to represent the scale of the pyramid accurately.
Pyramid of energy (What is it? What are the limitations?)
● An ecological pyramid that shows the amount of energy that is available at each trophic level
● Limitations:
- It is difficult to obtain exact values of available energy in an ecosystem
How much energy is transferred between trophic levels?
Only ~10% of the energy is actually converted into animal biomass/stored.
What happens to the energy that is not transferred to the next trophic level?
● Used to obtain/digest food, repair damaged tissues, other life functions, etc.
● 80-90% of the food energy is used for chemical reactions in the body and eventually is lost to the ecosystem in the form of heat.
Nutrient
● Chemicals that are required for plant and animal growth and other life processes.
● They are accumulated for short and long periods of time in Earth’s atmosphere, oceans, and land masses
Store
● Accumulations of nutrients for short or long periods of time in Earth’s atmosphere, oceans, and land masses.
Nutrient cycles
● The continuous flow of nutrients in and out of stores
● Nutrient cycles are nearly in balance because, without human interference, the amounts of nutrients flowing into the stores are nearly the same as the amounts flowing out of the stores
How does human activity affect nutrient cycles in general?
● Activities such as land clearing, agriculture, urban expansion, mining, industry, and motorized transportation can affect a nutrient cycle by increasing the amounts of nutrients in the cycle faster than natural biotic/abiotic processes can move them back to the stores.
● Over time, increase amounts of nutrients in the atmosphere/oceans/land can have significant effects on the environment
What are the three important nutrient cycles covered in section 2.2?
- Carbon cycle
- Nitrogen cycle
- Phosphorus cycle
Where are short-term stores of carbon found?
● Vegetation on land/oceans ● Animals ● Decaying organic matter in soil ● Atmosphere (CO2) ● Top layer of the ocean
Where are long-term stores of carbon found?
● Intermediate/deep ocean waters
● Coal/oil/gas deposits
● Marine sediments/sedimentary rock
Sedimentation
● The process that contributes to the formation of sedimentary rock
● During sedimentation, soil particles and decaying/dead organic matter accumulate in layers on the ground or at the bottom of oceans and other large bodies of water.
- These layers are turned into rock by slow geological processes that take place over long periods of time
- Some marine sediments and sedimentary rock form from the shells of marine organisms such as coral and clams, which contain calcium carbonate.
What is carbonate? How does it relate to sedimentation?
● A combination of carbon and oxygen that is dissolved in ocean water.
● Found in the shells of some marine organisms
- When these marine organisms die, their shells accumulate on the ocean floor, forming carbonate-rich deposits. The carbonate eventually becomes sedimentary rock (limestone) over time.
What are some of the major stores of carbon on Earth?
In order from the most carbon to least:
- Marine sediments/Sedimentary rock
- Oceans (intermediate and deep water)
- Coal deposits
- Soil and organic matter
- Atmosphere
- Terrestrial vegetation
- Oil and gas deposits
(Refer to table on pg. 73)
List some natural processes that cycle carbon through ecosystems.
- Photosynthesis
- Cellular respiration
- Decomposition
- Ocean processes
- Natural events (ie. volcanic eruptions, forest fires, etc.)
