AP Environmental Science: Unit 1 Review - Ecosystems

Introduction to Ecosystems

• ecosystem - interactions of abiotic and biotic factors
  
• symbiosis - a long-term interaction between two species in an ecosystem 
• mutualism - benefit both species (+,+)
• commensalism - one species benefit while the other is unaffected (+,o)
• paratism - one species live on/in the other (host) is harmed (+,-)

Food Web and Food Chains

• food web - depicts the flow of energy in 2 or more food chains
• competition - individuals from different species (interspecific) or same (intraspecific) struggle to obtain limited resources
• resource partitioning - species use limited resources in different ways to reduce competition
• 10% rule - approximates that in transfer of energy from one trophic level to the next, only about 10% of the energy is passed on

Primary Productivity

• Primary Productivity - rate at which sunlight is converted into organic compounds over a unit of time
• Gross Primary Productivity (GPP) - total rate of photosynthesis in a given area
• Net Primary Productivity (NPP) -  rate of energy storage by photosynthesizers in a given area, after subtracting the energy lost to respiration

The Carbon Cycle

• The Carbon Cycle - the movement of molecules containing carbon between sources & sinks 
• Main sinks -  the atmosphere, living things, the ocean, sediment, & fossil fuels
• Decomposition - releases CO2. burial of organic life stores carbon in sediment & fossil fuels
• Photosynthesis and Cellular Respiration are also apart of the Carbon Cycle

The Nitrogen Cycle

• The Atmosphere is the largest reservoir of nitrogen
• Nitrogen Fixation - process in which atmospheric nitrogen (N2) is converted by bacteria into a form of nitrogen usable by plants 
• Nitrogen Assimilation - plants use nitrogen to build tissue

The Phosphorus Cycle

• The Phosphorus Cycle - movement of  molecules containing phosphorus between sources and sinks
• Major reservoirs - rock and sediment
• Phosphorus a limiting growth factor in aquatic and many terrestrial ecosystems

The Water Cycle

• The Water Cycle - movement of water in in solid, liquid, and gaseous forms between sources and sinks
• Powered by the Sun
• Main reservoir - oceans, ice caps, groundwater  

Terrestrial Biomes

• Biome - contains characteristic communities of plants and animals that result from, and are adapted to, its climate
• Terrestrial Biomes - taiga, temperate deciduous forest, tropical rainforest, shrubland, temperate grassland, savanna, desert, and tundra
• taiga - a cool forest biome of conifers in the upper Northern Hemisphere, long, cold winters and small amounts of precipitation, northern coniferous forest composed of pine, fir, hemlock, and spruce tree, soil is acidic and mineral-poor
• temperate deciduous forest - the biome in southeastern Canada, and eastern United States, warmer temperatures lots of precipitation, huge forests 
• tropical rainforest -  biome near the equator, most diverse and hottest terrestrial biome, warm climate wet weather, high plant growth
• shrubland - biome around California coast and the Mediterranean Sea, hot summers and mild, rainy winters, contains fire-tolerant shrubs
• temperate grassland - biome found in North America, Eurasia, South America and Africa, nutrient-rich soil, cold winters and rainfall, grasses and few trees
• savanna - a grassland biome with scattered individual trees, large herbivores, three distinct seasons, occasional fires and drought
• desert - a biome characterized by low moisture levels and infrequent and unpredictable precipitation,  little rainfall supports only sparse or no vegetation at all
• tundra - biome in the Arctic and Antarctica, coldest of all the biomes, lots of lichens, mosses, sedges, and dwarfed shrubs, cold climate, permafrost, low biotic diversity

Aquatic Biomes

• Freshwater Biomes -  streams, rivers, ponds, and lakes
• streams/rivers - A freshwater ecosystem in which the water flows in a current
• ponds/lakes - A body of fresh water that is surrounded by land and that does not flow
• Marine Biomes -  oceans, coral reefs, marshland, and estuaries
• oceans - deep ocean water located away from the shoreline
  
• coral reefs - most diverse marine biome, warm, shallow waters beyond shoreline
• marshland - found along the coast in temperate climates, contains non-woody merging vegetation 
  
• estuaries - a coastal body of water, partly surrounded by land, with access to the open ocean and a large supply of fresh water from a river