The natura water cycle

Evapotranspiration we

Science Test Review (Ecosystems)

* The Spheres of the Earth: are found on the Earth's surface Atmosphere (Air):

* Gases above the Earth's surface * E.g. of life in the BIOSPEHERE: bacteria, birds, bats

Hydrosphere (Water): * All water foundon Earth (oceans) * E.g. of life in the BIOSPHERE:

sharks, whales, dolphins

Lithosphere (Rok):

* Hard part of Earth's surface * E.g. of life in the BIOSPHERE:

worms, moles, plants, "us"

Biosphere (Life): The life found in all of the other spheres

-4- Water Cycle:

4- Carbon Cycle: Carbon is an essential nutrient that moves through the spheres as carbon dioxide gas (CO 2 )

Carbon is found in: • The lithosphere as:

* carbon trapped in dead organisms (oil,gas) * carbon trapped in rocks, e.g. limestone or chalk * carbon trapped in living organisms

The atmosphere as:

carbon dioxide gas (CO 2 )

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Science Test Review (Ecosystems)

♦ The hydrosphere as:

■ dissolved CO 2 which is called carbonic acid

■ coral and other living organisms

* Nitrogen Cycle: * Atmosphere:

■ 78% of the air we breathe is nitrogen

■ nitrogen is found as N 2 gas which most organisms can't do anything with

■ N 2 is made by bacteria living in the roots of plants

* Lithosphere: (terrestrial ecosystem)

■ bacteria converts N 2 gas into usable forms that can be absorbed by plants

■ nitrogen gets into the food web since herbivores eat the plants ■ a major source of usable nitrogen comes from factories

■ humans invented the "Haber-Bosch process" that turns N 2 gas into solid fertilizer

tt> Hydrosphere: (aquatic ecosystem)

■ cyane bacteria turn N 2 gas into a form that plants can use

■ nitrogen can get into the aquatic ecosystem through sewage and fertilizer run-off from fields

* Phosphorus Cycle: Atmosphere:

■ not present — not found as a gas b Lithosphere:

■ stored in rocks ■ released from rocks by weathering or humans ■ leeches into soil, absorbed by plants ■ when plants die, returned to soil ■ applied to soil by humans as fertilizer

tt> Hydrosphere: ■ gets into water by run-off from rocks and mining ■ ends up at the bottom of the ocean floor as sediments ■ gets mined from ocean floor many million years later

* Photosynthesis: > a process that changes solar energy into chemical energy

> 6C0 2 + 6H 2 0+ sunlight 4 C 6 H 12 0 6+ 60 2

> carbon dioxide + water + sunlight 4 glucose + oxygen > takes place in chtoroplasts > Photo: light ; Synthesis: put together > Plant cells use the compound chlorophyll — Chloros: green ; Phyllon: leaf > Carbon atoms are transferred to carbohydrates

*- Cellular Respiration: > a process that releases energy from glucose (and fat and protein) in the presence of oxygen

> C 6 H12O 6 + 60 2 > 6C0 2 + 6H 2 0 + energy

> glucose + oxygen 4 carbon dioxide + water + energy > takes place in mitochondria; used by animals and plants

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Science Test Review (Ecosystems)

*- Trophic Levels (The Biosphere): a category of organisms that is defined by how the organisms get their food

1st Trophic Level 2nd Trophic Level 3 rd Trophic Level 4th Trophic Level

Decomposers Primary Producers

(grass) Herbivores

(grasshopper) Carnivores/Omnivores

(bird) Top Carnivores

(bear)

q) Primary producers are the only ones that make their own food tt> Through this cycle, energy and nutrients cycle through the atmosphere > Decomposers are essential for breaking down organisms and releasing nutrients after organisms die

*- Trophic Efficiency: the amount of energy transferred from one trophic level to another measured as a percentage (%)

W some energy is lost from the system each time energy is transferred tt> Reasons energy is lost

4 1) Herbivores — don't eat all the plants they rip up • 2) Not everything that is eaten is digested • 3) Animals use energy to move and stay warm • 4) Other? Because energy is lost between each step (inefficiency) there is always less biomass in a higher trophic level than in a lower level.

*- Threats to Biodiversity: natural and man-made events threaten biodiversity

-•.> Threats: • 1) Habitat Loss

• due to natural disaster or human activities • destroy where organisms live and reproduce • E.g. #1: deforestation — burn the Amazon rainforest for hamburgers • E.g. #2: draining wetlands to make farmland — PROBLEM: wetlands prevent flooding

* 2) Overexploitation • humans use too much • E.g. #1) Atlantic cod — In 1960, caught 1000 tonnes 4 In 2000, caught 200 tonnes • E.g. #2) Passenger pige*n 1850s, 5 000 000 000 4 In 1909, 0 (.'. extinct) caused by

habitat loss and hunting • 3) Alien Species

• humans introduce a new species • some don't destroy though others become INVASIVE wri* E.g. zebra mussels (1980s), round gobi (1990)

• 4) Disrupting Connection in Ecosystems ■ E.g. remove a food source for a predator and the predator dies out

• 5) Extinction ■ if something is extinct, it can never come back

*- Restoration Ecology: q> Environmental stewardship is the idea that humans are responsible for the world around them

where humans destroyed the environment, they should also restore it tl'a make a restoration plan (e.g. Don Valley Bricks Works)

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Science Test Review (Ecosystems)

* Restoration methods • 1) Reforestation • 2) Wetlands Restorations • 3) Controlling Alien Species (e.g. biocontrol, chemical control) • 4) Bioremediation

*- Key Terms:

* Alien species: a species living outside of its native habitat, which has arrived there by human activity (also known as exotic species, non-native species, introduced species, invasive species)

Abiotic: the non-living physical and chemical components of an ecosystem E.g. water, rock, sunlight

• Bioaccumulation: the process where more toxic materials are eaten than eliminated

• Biocontrol: the control of destructive organisms by the use of other organisms, such as the natural predators of the pests

• Biodiversity: the number and variety of organisms found within a specific region (highest in the tropics, E.g. Lake Malawi — Africa, Lake Erie — Ontario)

* Biodiversity hotspot: a place where there is an very large number of species in a relatively small area (E.g. Ontario — Carolinian Forest: 1% of Canada's area, has 2200 of Canada's 5500 plants and 40% of breeding birds)

Biomagnification: when the concentration of a toxin gets higher from one trophic level to another (E.g. DDT, an insecticide, entered lakes and rivers where it was absorbed by algae, fish ate the algae, and then, birds ate the fish. Each time an organism ate an organism that had DDT in it, biomagnification occurred.)

+ Biomass: the total mass of living organisms in an area; includes all the bacteria, plants, animals, fungi

* Bioremediation: the use of biological agents, such as bacteria or plants, to remove or "suck up" contaminants, as in polluted soil or water.

• Biotic: living things; their remains; and features such as nests, in an ecosystem E.g. human, tree, fish

Carrying capacity: the maximum number of individuals that a given environment can support without harmful effects

Community: a group of interdependent organisms inhabiting the same region and interacting with each other

Competition: the rivalry between or among organisms for resources like food, water, space, shelter

Deforestation: The cutting down and removal of all or most of the trees in a forested area. Deforestation can erode soils, contribute to desertification and the pollution of waterways, and decrease biodiversity through the destruction of habitat.

Dominant species: species that are so abundant that they have the biggest biomass of any community member

+ Ecosystem: a system involving the interactions between a community of living organisms in a particular area and its nonliving environment

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Science Test Review (Ecosystems)

Equilibrium: the balance between opposing forces

* Exponential growth: rapid population growth that produces a J-curve when graphed

Fermentation: a process similar to cellular respiration, but instead of producing H 2 0 (water) and CO

(carbon dioxide), it makes ethanol (alcohol)

Intensification: the creation of high-density residential areas and compact development

* Keystone species: a species that can greatly affect population numbers and the health of an ecosystem

* Limiting factor a factor that limits the growth, distribution or amount of a population in an ecosystem

• Mutualism: a kind of co-operation between two organisms when they interact with one another, where each receives a benefit from the relationship

• Niche: a unique position that an organism has in an ecosystem

• Organism: a living thing: plant, animal, or single cellular organism

▪ Overexploitation: when humans use or destroy too much resources/species

• Population: group of organisms of the same species inhabiting a given area

• Protect: to guard legally from harm a species that is listed as endangered, threatened, or of special concern

• Resource: something that organisms use to live or reproduce

• Reforestation: the process of planting new trees in areas where they have been removed by cutting or destroyed by fire, disease, etc.

• Species: a group of organisms that can reproduce and producing fertile offspring

▪ Succession: the series of change in an ecosystem that occurs over time, following a disturbance

• Sustainable ecosystem: an ecosystem that is capable of withstanding pressure and giving support to a variety of organisms

Sustainability: using a resource so that the resource is not depleted or permanently damaged

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