Biosphere

• Biosphere


  Where the atmosphere, lithosphere, & hydrosphere function together to form the environment in which life exists
• Components of the biosphere


  • Ecosystem
  • Food Chain
  • Global Distribution
  • Succession
  • Terrestrial
  • Aquatic
• Biosphere


  • Contains all plant and animal life
  • Extends from sea floor (~−11 km) to ~+8 km above the earth's surface
  • Includes all living and non-living parts
• Abiotic


  Non-living parts of the environment
• Biota


  A collection of just living things in the biosphere
• Biotic Factors


  Any living part of the environment with which an organism might interact
• Biotic Factors


  • Animals, plants, mushrooms & bacteria
• Abiotic Factors


  Any nonliving part of the environment
• Abiotic Factors


  • Sunlight, heat, water, soil, etc.
• Habitat


  The area where an organism lives; includes both biotic and abiotic factors
• Biogeography


  Study of the distribution of plants and animals
• Ecology


  The study of interactions among organisms and between organisms and their environment
• Interdependence


  Dependence of every form of life on other living things and natural resources (air, water, land) in its environment
• Ecosystem


  Collection of all organisms in a particular place together with the abiotic (physical) environment
• Biome


  A group of ecosystems with the same climate (temp. and rainfall)
• Community


  Groups of different populations that live together in a defined area
• Population


  Groups of individuals of same species in same area
• Species


  Group of organisms so similar that they can mate and produce fertile offspring
• 99.9% of all species that have existed on Earth are now extinct
• Components of the food chain


  • Producers
  • Consumers
  • Decomposers
• Producers


  Plants - use CO2 and light to form biomass
• Consumers


  • Primary consumers (herbivores)
  • Secondary consumers (carnivores)
  • Tertiary consumers (omnivores, humans)
• Decomposers


  Break down organic matter - release nutrients
• ~20 plant species provide 90% of world's food
• 3 plant species that provide ~50% of the world's food


  • Wheat
  • Maize (aka corn)
  • Rice
• Factors that determine vegetation distribution


  • Temperature
  • Sunlight
  • Water (moisture)
  • Wind
• Vegetation sorting along environmental gradients occurs across a range of scales: continental, landform, and microscale
• Limiting factors that determine species distribution and size


  • Biotic (living): Disease, predators, parasites; Food availability; Ability to adapt, compete
  • Abiotic (non-living): Microclimatic controls; Geomorphic and edaphic controls; Element (nutrient, & chemical) cycling
• Microclimate


  Determined by site-specific factors like sunlight, water, wind, humidity, and temperature reaching the forest floor

  
• Geomorphic factor

  Slope (steepness) and aspect (orientation) - important controls of temperature and moisture
• Edaphic factor


  Soil type - determines fertility, texture, water holding capacity, nutrients, acidity, salinity, etc. Determined by climate, parent material, and time
• Ecosystem


  A self-sustaining association of plants and animals and their physical environment, constantly changing in response to environmental conditions and disturbances
• Succession

  Older, more simple communities are replaced by newer, more complex communities
• Types of terrestrial succession


  • Primary: beginning of a new ecosystem (e.g. plants on bare rock, newly exposed surfaces)
  • Secondary: starts from remains of previous ecosystem in disturbed area, where soil remains intact
• Stages of aquatic succession

  • Oligotrophic (low nutrients)
  • Mesotrophic (medium nutrients)
  • Eutrophic (high nutrients)