envi unit 1- study guide

• Ecology


  The study that deals with the relationships of organisms (species) to one another and their interactions with their physical surroundings
• Species


  A group of organisms that are genetically similar and interbreed with one another to produce live, fertile offspring
• Population


  All members of a species living in a given area at the same time
• Community


  All of the populations of organisms living and interacting in a particular area
• Ecosystem


  All of the populations in a given area (biological community) together with the nonliving components
• Justus von Liebig (1840) stated that the single factor which is in short supply relative to demand is the critical factor that determines the distribution of a particular species
• Victor Shelford further explained that each environmental factor has both maximum and minimum levels called tolerance limits beyond which a given species will fail to survive
• Tolerance limits


  • Zone of intolerance
  • Zone of physiological stress
  • Optimum range
  • Zone of physiological stress
  • Zone of intolerance
• The presence or absence of environmental indicators can give information about the biological community and ecosystem
• Levels of biological organisation

  • Atom
  • Molecule
  • Cell
  • Tissue
  • Organ
  • System
  • Organism
  • Population
  • Community
  • Ecosystem
  • Biosphere
• Indicator species are important in population studies because they give an indication of the health of the ecosystem, while keystone species can indicate the presence of certain other populations in the same ecosystem
• Biological communities are limited by biological or biotic factors such as predators and available food resources
• Autotrophs


  Organisms that make their own food by photosynthesis (producers)
• Consumers


  • Herbivores
  • Carnivores
  • Omnivores
  • Detritivores
• Decomposers are important in recycling of nutrients
• Ecological succession


  1. Initial colonisation

  2. Replacement by other species (Competition, natural selection, habitat changes)

  3. Development of a stable species distribution and habitat
• Interconnected parts of the Earth's system

  • Biosphere
  • Atmosphere
  • Hydrosphere
  • Lithosphere
• Atmosphere


  The layer of air that surrounds the planet Earth
• Hydrosphere


  The part of the Earth that is composed of all of the water on or near the Earth
• Biosphere


  The part of the Earth that supports all life
• Lithosphere


  The Earth's outermost solid shell, consisting of the crust and the uppermost portion of the mantle
• Freshwater biomes


  Areas of low salt content that organisms living in cannot survive in areas of high salt content such as marine regions
• Estuaries


  Areas where there is mixing of fresh water and marine water, described as being brackish
• Estuaries support a diverse array of flora and fauna
• Coral reefs


  Distributed in warm, shallow waters, may be found as barriers along continents or as fringing islands and atolls
• Layers of the Earth

  • Crust
  • Mantle
  • Core
• Crust


  Outermost layer made up of the lightest material
• Mantle


  Middle layer, approximately 66% of the Earth's mass
• Core


  Innermost layer, approximately 33% of the Earth's mass
• Types of lithospheric crust

  • Continental crust
  • Oceanic crust
• Continental crust


  Composition similar to granites
• Oceanic crust


  Composition similar to basalt, denser than continental crust
• The biosphere, atmosphere, hydrosphere and lithosphere are four interconnected parts that form a system
• Conduction, convection and radiation are responsible for transferring energy between the Earth's surface and the atmosphere
• Hydrosphere


  Part of the Earth composed of all the water on or near the Earth
• All living organisms are components of the biosphere, which is divided into biomes
• Main types of biomes

  • Aquatic
  • Desert
  • Forest
  • Grassland
  • Tundra
• One of the main reasons for classifying the biosphere into biomes is to highlight the important effect that physical geography has on communities of living organisms
• Vegetation types are very useful when describing different biomes
• Physical layers of the Earth

  • Lithosphere
  • Asthenosphere
  • Mesosphere
  • Outer core
  • Inner core