ecosystems + evolution

• Ecosystem: a biological community of interacting organisms and their physical environment (as well as chemical)
• Ecology


  the study of how the different organisms interact with each other
• Abiotic: physical rather than biological; not derived from living organisms (non living)
• Biotic: relating to or resulting from living organisms
• Ecotones: The transition zone between two ecosystems. It contains species from both of the two ecosystems.
• Ecological Niche: The range of conditions within which a species can survive and reproduce. (Reduces competition)
• Biome: A large geographical area that has a specific range of temperatures and precipitation.

  organisms that live in that specific biome are adapted to its conditions
• terrestrial ecosystems are found on land and are dominated by plants
• Tundra: a vast, flat, treeless Arctic region of Europe, Asia, and North America in which the subsoil is permanently frozen. Animals have fur and smaller ears, shrubs and grasses, snow and very little precipitation, cold, short growing season
• Grassland: an extensive tract of level country covered with grasses and herbaceous plants; prairie. Grassy plains, savannas, steppes, pampas, veldts, etc. Are all examples of grasslands. They are characterized by low rainfall, high temperature, and long periods without rain. There are few trees but many bushes and tall grasses. Many animals such as buffalo, antelopes, zebras, lions, hyenas, wolves, foxes, rabbits, squirrels, mice, birds, reptiles, insects, etc., live here.
• Taiga: dominated by conifers, the canopy recieves the most sunlight, and the ground is covered in mosses and lichens
• Muskeg: a swamp or bog in northern North America, due to permafrost, includes lichens, mosses, grass, shrubs, etc.
• Deciduous Forest: A forest that is dominated by deciduous trees, which shed their leaves in the winter. Sun reaches the ground.
• Soil: provides nutrients for all plants that grow on land
• Litter: uppermost layers of soil, usually decomposed plant material, that is left after the removal of the vegetation
• Topsoil: small particles of rock and humus, consists mainly of decaying plant and animal matter
• Subsoil: contains more rock particles and less organic material than topsoil
• Bedrock: layer beneath soil that is a firm layer of rock
• Available Water is the water that is available for use by plants and animals.
• Ground water is water that is found in the soil and is not part of the surface water
• Temperature: apart of climate and affects Abiotic and Biotic factors
• Sunlight affects all ecosystems (terrestrial)
• Aquatic Ecosystems


  Cover more than 67% of the earth

  97% is salt water
• Pond: light is able to reach the bottom
• Lake: large body of freshwater, deepest parts are darker so less sunlight reaches it
• Types of Lakes

  oligotrophic: deep and cold lakes with low nutrient levels (newer)
• Types of Lakes

  Eutrophic: shallow and warmer lakes with high nutrient levels (older)
• Zones of Lakes

  Littoral: shoreline and extends to where aquatic plants cease to grow
• Zones of Lakes

  Limnetic: starts at end of littoral, extends into open water where there is enough light for PS
• Zones of Lakes

  Profundal: beneath limnetic, not a good amount of light for PS
• Chemical Environment: oxygen content, minerals, pollutants. Dead animals, plants and debris from wind and erosion cause the shallow end of lakes to show signs of aging. (Eutrophication)
• Temperature and sunlight: near the surface there are warmer temps (less o2) and in winter it is colder (more o2)
• Water Pressure: the deeper you go the more pressure
• Seasonal Variation

  • Winter Stagnation: covered in ice and snow, prevents atmospheric o2 from dissolving
  • Spring Overturn: stirring of water that increases the SA and oxygen dissolving rate in water increases
  • Summer Stagnation: warmer the water the lower amount of o2 dissolved
  • Fall Overturn: decrease in air temp, renews oxygen at all depths
• Epilimnion: the upper layer of water in a stratified lake. (Above 4 degrees)
• Hypolimnion: The bottom layer of the water column in a lake or pond. (Cold)
• Thermocline: A layer of water with a different temperature from the surrounding water. They layer inbetween epilimnion and hypolimnion
• Biotic Potential: The maximum number of individuals that can be supported by a particular environment.
• birth potential: # of offspring produced
• capacity for survival: the ability to survive in the environment and to reproduce