3-3 第八大段 (作業)

< Energy Flow and Nutrient Recycling Sustain Ecosystems >

Ecosystems and the biosphere are sustained through a combination of one-way energy

flow from the sun and nutrient recycling .


these two scientific principles of sustainability arise from the structure and

function of natural ecosystems , the law of conservation of matter , and the two

laws of thermodynamics.




Decomposers and detritus feeders are absolutely essential to life on the earth.


They complete the cycling of matter by breaking down organic matter into

simpler nutrients that can be reused by producers.


Without decomposers and detritus feeder, the planet would be overwhelmed with

plant litter, dead animal bodies, animal wastes, and garbage .


In addition, most life as we know it could not exist beause the nutrients stored in

such wastes and dead bodies would be locked up and unavailable for use by oter

organisms .