BIOL 150 Chapter 3

• Ecology


  The study of how organisms interact with each other and their environment
• Levels of ecology


  • Organisms
  • Populations
  • Communities
  • Ecosystems
  • Biosphere
• Organismal ecology


  The study of how morphological, physiological, and behavioral adaptations increase fitness in a particular environment
• Population


  A group of individuals of the same species that lives in the same area at the same time
• Population ecology


  How the number and distribution of individuals in a population change over time
• Community


  Populations of different species that interact with each other within a particular area
• Community ecology


  Questions about the nature and consequences of species interactions
• Ecosystem


  All the organisms in a particular region along with non-living components
• Ecosystem ecology


  The study of how nutrients and energy move among organisms and through the surrounding atmosphere, soil, or water
• Abiotic


  Nonliving components
• Biotic


  Living components
• Biosphere


  A thin zone surrounding the Earth where all life exists
• Global ecology


  Studies the effects of human impacts on the biosphere
• Climate


  Prevailing, long-term weather conditions found in an area
• Weather


  Specific short-term atmospheric conditions of temperature, precipitation, sunlight, and wind
• Global climate system


  Powered by solar radiation
• Incoming solar radiation


  Not constant across the globe due to the shape of the Earth
• Regions near equator


  Receive more sunlight per unit area than regions near poles
• Cycles in global air circulation


  Influence global precipitation patterns
• Locations of deserts across the globe are at 30, 60, and 90 degrees
• Hot air


  Less dense, has lower pressure, rises, and holds more water
• Cold air


  More dense, has higher pressure, falls, and holds less water
• Cooling and heating of air

  Produces "cells"- cyclical movement of air molecules
• The Hadley Cells


  Result in heavy rainfall at the equator
• Main cells that influence global patterns of precipitation


  • Hadley Cell
  • Midlatitudinal Cell
  • Polar Cell
• Tradewinds


  Determine the direction and size of cells
• Seasons


  Regular, annual fluctuations in temperature, precipitation, or both
• Seasons


  Caused by the tilt of the Earth on its axis
• If the Earth wasn't tilted on axis, there would be no seasons
• Seasonality


  The degree of difference between summer and winter temperatures in a region
• Seasonality


  Higher at the poles and increases with latitude
• At the equator


  Little variation of seasons because the equator is hit directly year round
• At increased latitudes


  Distance from sun varies by season
• Mountain and oceans


  Increase regional climate
• Oceans


  Have moderating influence on temperature because water has high specific heat
• Islands and coastal areas


  Have more moderate climates than inland areas
• Ocean currents


  Influence local climate patterns
• Gyres


  Cyclical ocean currents that move warm water to more northern latitudes and cold water to more tropical latitudes
• Biomes


  Regions characterized by distinct abiotic characteristics and dominant types of vegetation
• Abiotic characteristics governing terrestrial biomes


  • Temperature
  • Moisture
  • Sunlight
  • Wind