Intro To Ecosystems
What is an example of a parasitic, commensalism, and mutualistic relationship?
parasitic-one organism lives benefits off of the other but harms the other organism
commensalism-both organisms do not affect one another
mutualistic-both organisms benefit
Which biome is characterized by low temperatures and low amounts of rainfall?
tundra
Describe a biological process by which carbon is removed from the atmosphere and converted to organic molecules
Photosynthesis
What is primary productivity?
The rate at which energy is converted to organic substances by photosynthetic producers (conversion of sun's energy into organic material through photosynthesis)
What is a food chain? What is a food web?
A hierarchical series of organisms each dependent on the next as a source of food.
A system of interlocking and interdependent food chains.
List 1 biotic and 1 abiotic factor in an ecosystem
biotic: plants, animals, bacteria
abiotic: temp, sunlight, air, minerals
Which biome do we live in?
Temperate forest
Identify one terrestrial sink other than fossil fuels that stores carbon for thousands to millions of years
Old-growth forests/trees that live for thousands of years
• Trapped/incorporated into ice caps/glaciers
• Limestone or sedimentary rocks
• Incorporation into soil
• Freshwater wetlands/bogs
• Peat formation/burial of plant material under anaerobic conditions
• Dissolved in aquifers
What is the difference between autotroph and heterotroph?
Autotroph: plant capable of making its own food from simple organic substances
Heterotroph: organism that depends on complex organic substances for nutrition
What role do decomposers play in a food chain?
They return raw material to the ecosystem since they get their energy by eating wastes and dead organisms
Order these in smallest to largest based on which they make up: organisms, ecosystems, biosphere, communities, and populations.
1-organisms
2-populations
3-communities
4-ecosystems
5-biosphere
Which biome has coniferous trees?
Taiga
Describe one major way in which the phosphorus cycle differs from the carbon cycle
Phosphorus cycle does not typically have a gas/atmospheric phase
It is more difficult for living organisms to access phosphorus since it has to be weathered from rocks and minerals (phosphorus cycle is much “slower” than the carbon cycle; phosphorus has fewer sinks than carbon)
How do primary, secondary, and tertiary consumers link?
Primary consumers make the food, secondary consumers consume primary consumers, and tertiary consumers consume secondary consumers
Name one way plants help animals and vice versa
Plants help animals by giving them oxygen, animals give plants nutrients when they eventually decompose
Haiti shares a border with the Dominican Republic on the Caribbean island of Hispaniola.
(a) The border between the two countries can be seen using satellite images because of the severe deforestation in Haiti.
(i) Provide one reason why deforestation commonly occurs in a less developed country such as Haiti.
Converting forests into agricultural land, ranchland
• Using trees/charcoal for fuel or source of income
• Protecting forests through regulations is less common than in developed countries
• Harvesting timber for use as building materials
• Using forested land for commercial purposes by corporations/industrialized countries
• Clearing forested land to accommodate growing rural populations (e.g., roads, homes, schools)
What is an estuary?
Area along the coast where fresh water from rivers mixes with salt water from the ocean
Discuss two human activities that increase the concentration of carbon in the atmosphere
deforestation, biomass burning, trash incineration, slash and burn farming, deep plowing, landfills, destruction of wetlands
Discuss the energy flow through an ecosystem
energy loss through each trophic level as a result of metabolic activity (key point)
As the amount of sea ice has decreased, larger expanses of the Arctic Ocean are now completely free of sea ice for several weeks each summer. Ringed seals, the preferred prey of polar bears, come to holes in the sea ice to breathe.
Explain how melting sea ice leads to a feedback loop that increases Arctic warming.
Melting of sea ice leads to a decrease in reflectivity, which leads to water surfaces absorbing more of the sun's energy.
AND
Increasing absorption of sun's energy warms the water surface further, which leads to further ice melt (completes positive feedback loop).
Haiti shares a border with the Dominican Republic on the Caribbean island of Hispaniola.
(a) The border between the two countries can be seen using satellite images because of the severe deforestation in Haiti.
(ii) Describe one realistic strategy to reduce deforestation in a less developed country.
Enact/enforce laws or regulations that restrict cutting of trees
• Encourage sustainable agriculture/forestry programs
• Introduce more efficient cooking methods that reduce use of wood as a fuel source
• Establish programs to promote alternate building materials that reduce the demand for wood
• Develop economic programs to increase individual incomes/decrease reliance on forest conversion
• Reduce population growth resulting in less demand for wood for fuel and income
• Promote ecotourism to protect natural areas and to discourage tree harvesting
Rivers/Streams
Identify an environmental problem that results from elevated atmospheric carbon concentrations. Also include a consequence of the problem identified.
problem: global warming, sea levels rising, ice caps melting, ocean acidification, reduction in air quality
consequences: species not surviving temp changes, coastal habitats flooding, lower pH may be lower than tolerance level of some species, hazardous for animals to breathe in air
Explain why it takes many hectares of wetland to support a pair of eagles.
To support a pair of eagles, there must be a large amount of biomass at lower trophic levels.
Less energy is available at each successive trophic level, because as energy moves up the food chain, much of it is: lost as heat (10 percent rule) or lost as metabolic work; or transformed into a less usable form/becomes less organized (second law of thermodynamics).
A food web is made of many different niches: decomposers, consumers (primary, secondary, tertiary...), and producers. Discuss each of these niches in the following ways: Explain what each niche's job is in the ecosystem.
Producers (autotrophs)-make their own food from compounds and energy obtained from their environment
Consumers (heterotrophs)-organisms that get energy & nutrients they need by feeding on other organisms or their remains primary consumers (herbivores), such as rabbits & zooplankton, eat producers secondary consumers (carnivores), such as foxes & fish, feed on herbivores tertiary & higher level consumers are carnivores that feed on other carnivores omnivores play dual roles by feeding on both plants and animals.
Decomposers-are specialized consumers that recycle nutrients in ecosystems