2008年1月22日 星期二

4.ecosystem and how they work

4.1 ecology and life
Greek words "oikos" house or place to live ."logos" study of.
organism, species, population, habitat, community(biological community), ecosystem, biosphere(ecoshphere).
what is life?

4.2 earth's life-support systems
four major parts:atmosphere, hydrosphere, lithosphere, biosphere.
three interconnected factors: the one-way flow of high-quality engergy form the sun, the cycling of matter or nutrients, gravity.
how does the sun help sustain life on earth? photosynthesis and natural greenhouse effect.

4.3 ecosystm concepts and components
major types of ecosystems? biomes生物群系(land), aquatic life zone水生生物帶(water).
major components of ecosystem?
abiotic(nonliving) range of tolerance, law of tolerance, tolerance limits, limiting factor, limiting factor principle.
biotic(living) producer-autotrophs, photosynthesis,chemosynthesis. consumer-heterotrophs, herbivores-primary consumers, carnivores-secondary consumers, tertiary consumers, omnivores, detritivores-detritus feeders and decomposers.
aerobic respiration, anaerobic respiration(fermentation發酵)

4.4 food webs and energy flow in ecosystem