Environmental Science Overview

The Spheres of Earth

• Biosphere: Zone around Earth where life exists
• Atmosphere: Layer of gases surrounding Earth
• Lithosphere: Earth's solid outer layer
• Hydrosphere: All of Earth's water in solid, liquid, and gas forms

Sustainability

• Biotic: Living parts of an ecosystem (eg. moose)
• Abiotic: Non-living parts of an ecosystem (eg. rocky cliffs)
• Ecosystem: Interacting parts of a biological community and its environment (living things and their environment)
• Sustainability: Ability to be maintained at a certain rate or level

Trophic Levels, Diets and Contaminants

• Trophic level: Category of organisms based on how they gain energy
• Autotroph: Organisms that create complex organic compounds from simple nutrients, often using sunlight (they make their own food)
• Heterotroph: Organisms that consume organic material to produce energy
• Trophic efficiency: The amount of energy or biomass transferred up trophic levels (always less than 100% due to energy loss during processes like hunting and digestion)
• Producer: Organisms that make their own food (eg. autotrophs)
• Consumer: Organisms that must eat other organisms for energy

Populations, Communities & Interactions

• Population: All individuals of a species in a given geographical area at a particular time
• Factors affecting population size: Natality (birth rate), immigration, fatality (death rate), emigration
• Interspecies interactions: Interactions between species that can have positive or negative effects on populations
• Ecological niche: The role an organism plays in an ecosystem (what it eats, what eats it, and its behavior)
• Predation & population size: Predator and prey populations influence each other

Communities

• Community: A group of different species occupying the same geographical area at a specific time
• Dominant species: Species with a large effect on the community
• Keystone species: Species with a disproportionately large impact on the community, often affecting many other species
• Ecosystem engineers: Species that create or modify habitats for other species

Cycles

• Biogeochemical cycles: Movement of matter through the biotic and abiotic environment
• Water cycle: Cycling of water through the environment (most water is in the abiotic environment)
• Carbon cycle: Cycling of carbon through the lithosphere, atmosphere, hydrosphere, and biosphere
• Carbon deposits: Fossil fuels (coal, oil, natural gas), oil shale, carbonate-based sedimentary deposits (limestone)
• Human impact on carbon cycle: Burning fossil fuels, land-use change, using limestone for concrete
• Nitrogen Cycle: Moving nitrogen compounds through biotic and abiotic environment

Carrying Capacity & Tolerance Range, 5 Types of Ecological Relationships

• Carrying capacity: Maximum population size an ecosystem can sustain
• Tolerance range: The range of abiotic conditions an organism can survive in
• Symbiosis (5 types): Interaction between members of two different species
  • Mutualism: Both individuals benefit
  • Commensalism: One individual benefits, the other is neither harmed nor benefited
  • Parasitism: One individual lives on or in a host and feeds on it
  • Competition: Two or more organisms compete for the same resource
  • Predation: One individual feeds on another

Aquatic and Terrestrial Biomes

• Terrestrial Biomes:
  • Tundra: Low temperatures, short growing season, permafrost, low diversity, mosses, lichens, caribou, ptarmigan, lemmings, arctic foxes
  • Mountain Forest: Varying temperatures with elevation, cool summers, windy conditions, heavy precipitation on leeward sides, fast-flowing rivers, marmots, squirrels, elk, black bears, grizzly bears, cougar, large coniferous trees, ferns
  • Boreal Forest: Warmer than tundra, no permafrost, changeable weather, higher precipitation, coniferous trees, seed-eating birds, squirrels, voles, snowshoe hares, black bears
  • Grassland: Longer growing season, higher temperatures, rich soil, precipitation (25-75 cm/year), fescue grasses, grasshoppers, bison, voles, mice, snakes, hawks, coyotes
  • Temperate Deciduous Forest: Longer growing season, fertile soil, precipitation (up to 100 cm/year), deer, weasels, squirrels, many insects, diverse tree and ground vegetation
• Aquatic Biomes:
  • Freshwater Ecosystems: Rivers, creeks, lakes, ponds, streams. Oligotrophic (low nutrients) and eutrophic (rich in nutrients)
  • Marine Ecosystems: Aquatic environments with high salt levels
• Watershed: An area of land that collects rain and snow and drains into a body of water

Vocabulary

• Atmosphere: Layer of gases surrounding Earth
• Lithosphere: Earth’s solid outer layer
• Hydrosphere: All of Earth’s water
• Ecosystem: Interacting parts of a biological community and its environment
• Biotic factor: Living things, their remains, and features associated with their activities
• Abiotic factor: Non-living physical and chemical components of an ecosystem
• Radiant energy: Energy traveling through empty space
• Light energy: Visible forms of radiant energy
• Thermal energy: Energy transferred during heating or cooling
• Photosynthesis: Converting sunlight into chemical energy
• Deforestation: Increased carbon dioxide in the atmosphere
• Producer: Organism that makes its own food
• Cellular respiration: Converting sugar into energy
• Consumer: Organism that obtains energy from consuming other organisms
• Decomposers: Organisms that break down dead or decaying organisms
• Food Chain: Sequence of organisms showing energy transfer, each organism feeds on the next
• Ecological Niche: Role a species plays in its ecosystem
• Trophic level: An organism's level in an ecosystem based on its feeding position
• Food web: Representation of feeding relationships within a community
• Ecological pyramid: Representation of energy, numbers, or biomass relationships in ecosystems
• Biomass: Mass of living organisms in a given area
• Herbivore: Eats plants or other producers
• Carnivore: Eats other animals
• Omnivore: Eats both plants and animals
• Scavenger: Eats dead animals
• Biogeochemical Cycle: Movement of matter through the biotic and abiotic environment
• Water cycle: Cycling of water through the environment
• Carbon Cycle: Cycling of carbon through the lithosphere, atmosphere, hydrosphere, and biosphere
• Nitrogen Cycle: Moving nitrogen compounds through the biotic and abiotic environment
• Limiting Factor: Factor that restricts the growth of a population
• Tolerance Range: Range of conditions an organism can survive in
• Competition: Organisms competing for the same resource
• Predation: One individual feeds on another
• Mutualism: Both individuals benefit from the interaction
• Parasitism: One individual benefits at the expense of the host
• Commensalism: One individual benefits, the other is unaffected
• Carrying Capacity: Maximum population size an ecosystem can sustain
• Biome: Large geographical region characterized by a particular set of climate, biotic, and abiotic features
• Aquatic Biome: Water-based biome
• Terrestrial Biome: Land-based biome