Earth from geological viewpoint. Earth from meteorological viewpoint.
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Transcript of Earth from geological viewpoint. Earth from meteorological viewpoint.
Levels of organization in the living world
• Organisms: individual living things
Levels of organization in the living world
• Population: group of individuals of same species occupying a given area at the same time.
Levels of organization in the living world
• Community: populations of all species occupying a particular place
Levels of organization in the living world
• Ecosystem: community(ies) interacting with one another and with the physical environment in a particular place
Levels of organization in the living world
• Biome: a major category of ecosystem (e.g., desert, grassland, tropical rainforest, etc.)
ECOLOGY• Ecology: the scientific study of
ecosystem structure and function• Ecologists vs. Environmentalists
Structure of ecosystems
2. Physical environment: non-living materials like air, water, minerals, etc.
Function of ecosystems
• All ecosystem interactions depend on–1. One-way flow of energy–2. Matter cycling
Energy Flow
• Energy: the ability to do work• Energy quality: measure of ability
to do work– High: organized, concentrated; great
ability to do work. Ex. electricity
Energy Flow
• Energy: the ability to do work• Energy quality: measure of ability
to do work– High: organized, concentrated; great
ability to do work. Ex. electricity– Low: disorganized or dilute; low
ability to do useful work. Ex. heat less than 100°C
Laws of thermodynamics
• 1. Matter and energy can’t be created or destroyed, only transformed – You can’t get something for nothing– There’s no such thing as a free lunch– E = mc2
• 2. Energy degrades to a less usable, lower quality form (low heat is lowest)– Energy quality “tax” – You can’t win– You can’t get out of the game, either
One-way flow of energy
– Food chain: a series of organisms, each eating or decomposing the preceding one. A channel for one-way flow of energy (and the recycling of materials).• Individual organisms
One-way flow of energy
• Food Web: a tracing of movement of all energy (and matter) passing through an ecosystem.
• Including all interconnected food chains
One-way flow of energy
• Some concepts– Pyramid of energy: due to the
“energy quality tax” of the second law of thermodynamics, only 2-30% of the energy a one trophic level is transferred to the next trophic level• Depends on species and ecosystems
involved• The “average” number is 10%
One-way flow of energy
– Pyramid of numbers and biomass: related to the pyramid of energy. • More people can be supported by plants
than by animal meat
One-way flow of energy• Pyramid of numbers and biomass:
1300
90,000
27,000,000
1000 tons
HumanTroutFrogs
GrasshoppersGrass
One-way flow of energy– Pyramid of numbers and biomass:
1300
90,000
27,000,000
1000 tons Grass
Human
Trout
Frogs
Grasshoppers
3090,000
27,000,000
1000 tons Grass
Humans
FrogsGrasshoppers
One-way flow of energy– Pyramid of numbers and biomass:
1300
90,000
27,000,000
1000 tons Grass
Human
Trout
Frogs
Grasshoppers900
27,000,0001000 tons Grass
Humans
Grasshoppers
One-way flow of energy– Pyramid of numbers and biomass:
1300
90,000
27,000,000
1000 tons Grass
Human
Trout
Frogs
Grasshoppers2,000
1000 tons Grass
Humans
One-way flow of energy– Net Primary Productivity: rate at
which plants produce chemical energy (PSS) MINUSthe rate at which plants use chemical energy (respiration)• The “income” of animals
Open ocean Tropical rain forest Temperate forest Savanna Northern coniferous forest Continental shelf Agricultural land Temperature grassland Woodland and shrubland Estuaries Swamps and marshes Desert scrub Lakes and streams Tundra Extreme desert
0 50 100 150 200
Average World Net Primary Productivity (billion Kcal/yr)
Estuaries Swamps and marshes Tropical rain forest Temperate forest Northern coniferous forest Savanna Agricultural land Woodland and shrubland Temperature grassland Lakes and streams Continental shelf Tundra Open ocean Desert scrub Extreme desert
0 2,500 5,000 7,500 10,000
?
Average World Net Primary Productivity (billion Kcal/m2/yr)Kcal/m2/yr
Estuaries Swamps and marshes Tropical rain forest Temperate forest Northern coniferous forest Savanna Agricultural land Woodland and shrubland Temperature grassland Lakes and streams Continental shelf Tundra Open ocean Desert scrub Extreme desert
0 2,500 5,000 7,500 10,000
?
Average World Net Primary Productivity (billion Kcal/m2/yr)Kcal/m2/yr