BIOL 226 Lecture Notes - Lecture 16: Detritivore, Emergence, Autotroph
3 May 2018
School
Department
Course
Professor
Biol226- Ch 55
Ecosystems
Ecosystem : sum of all the organisms in a given area and the physical environment with which they
impact
o A biological community and its interactions with the abiotic environment
Ecosystem dynamic ( emergent properties ) :
o Energy flow
o Chemical cycling
Energy mostly enters ecosystem as sunlight --> to chemical energy by autotroph --> to heterotrophs in
organic compound --> dissipated as heat
Energy cannot be recycled but chemical matter can be
Energy flows through an ecosystem but matter cycles
Conservation of energy
The amount of energy stored in organic molecules must equal the total solar energy intercepted by the
plant, minus the amounts reflected and dissipated as heat
Determined their source of feeding
Primary producers : trophic level that supports autotrophs
Primary consumers : herbivores which eat plants and other primary producers
Secondary consumers : Carnivores that eat herbivores
Tertiary consumers : Carnivores that eat other carnivores
Decomposers ( Detritivores ) : consumers that get their energy from detritus ( nonliving organic matter)
Detritus : nonliving organic material like remains of dead organisms , feces , fallen leaves , wood
Primary production : These photosynthetic products are the starting point for most studies of
ecosystem metabolism and energy flow.
Gross Primary Production ( GPP ) : Primary production , the amount of energy from light converted to
the chemical energy of organic molecules per unit time
Net Primary Production ( NPP ) : gross primary production minus the energy used by the primary
producers for their “autotrophic respiration” (Ra) [ J.m^(-2).yr^(-1) ]
the oceans are relatively unproductive, their vast size means that together they contribute as much
global net primary production as terrestrial systems do.
Net ecosystem production ( NEP ): total biomass accumulation during that time
Document Summary
Ecosystem : sum of all the organisms in a given area and the physical environment with which they impact: a biological community and its interactions with the abiotic environment. Ecosystem dynamic ( emergent properties ) : energy flow, chemical cycling. Energy mostly enters ecosystem as sunlight --> to chemical energy by autotroph --> to heterotrophs in organic compound --> dissipated as heat. Energy cannot be recycled but chemical matter can be. Energy flows through an ecosystem but matter cycles. The amount of energy stored in organic molecules must equal the total solar energy intercepted by the plant, minus the amounts reflected and dissipated as heat. Primary producers : trophic level that supports autotrophs. Primary consumers : herbivores which eat plants and other primary producers. Secondary consumers : carnivores that eat herbivores. Tertiary consumers : carnivores that eat other carnivores. Decomposers ( detritivores ) : consumers that get their energy from detritus ( nonliving organic matter)
