Earths systems

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Earths systems

• SPACESHIP EARTH The view of earth from 1972,
  made people aware that earth is a closed system.

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Systems a network of parts that exchange
energy, matter, and information
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• Negative feedback loop outputs from a system
  moving in one direction are inputs for another
  part of the system that move it in the opposite
  direction
• Causes stability
• When these input and outputs are periodic
  dynamic equilibrium

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• Cycles called oscillations

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• The earth is a closed system because it does not
  exchange significant amounts of matter with outer
  space.
• We do have a significant throughput of energy in
  the form of incoming sunlight and exiting radiant
  heat. That throughput, like the ecosystem, is
  also finite and nongrowing.
• For the earth, the basic rule is energy flows
  through, materials cycles within.

sunlight
heat
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Energy flow details
Amount absorbed by photosynthesis? 0.03 - very
small!
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• Plant conversion of solar energy into chemical
  bonds is primary production
• The rate is called primary productivity
• Gross primary production is all the energy
  converted by photosynthesis
• Net primary production is the energy that remains
  after plants metabolism or respiration

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Ecosystems vary in the rate at which plants
convert energy into biomass.

• Higher productivity
• Wetlands
• tropical rainforests
• Coral reefs
• Algal beds

• Lower productivity
• Deserts
• Tundra
• Open ocean

Lacks water
Lacks sunlight
Lacks nutrients
Main idea! The more autotrophs the more
productivity. --If plants can grow easily in the
climate, it will be a productive ecosystem.
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Energy flow through an ecosystem
Heat loss due to respiration
Sometimes there are tertiary consumers why is
this rare?
Energy available is too small.
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Notice the chemical cycle -
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Matter Cycling through an ecosystem
Lithosphere hydrosphere
biosphere
Hydrosphere atmosphere
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Matter travels between biotic and abiotic
components

• The molecules for life found in the lithosphere
  and hydrosphere are typically inorganic.
• There are specific processes needed to make them
  usable for life.

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All organisms have a particular set of matter and
energy needs.

• This specific environment is called a habitat

This epiphyte is an orchid that requires high
humidity, warm temperatures, and a tree branch
platform instead of soil.
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• Each population has a range of tolerance to
  various abiotic factors and its tolerance limits
  determine its abundance and distribution.

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Hardiness zones for plants

• Based on temperature ranges

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• The way an organism uses its resources and
  habitat result in its niche.

NO!