Lecture 23: Biogeochemical Cycling and Biomes Flashcards
-Energy Flow -Elemental Cycling -Biomes
What two conditions does life require to be met?
1) a flow of energy
2) the continual recycling of elements
What are autotrophs (primary producers)?
Organisms that produce organic matter via photosynthesis or chemosynthesis (primary production)
What are the two ways that primary producers use their produced biomass?
- they produce their own biomass
1) they use some of it to fuel their own metabolism, releasing energy in the form of heat
2) store some of the biomass for future use
What is gross production?
The production of organic matter before any use
What is net production?
The biomass that is left after it has been used to support its own metabolism
-net production = gross production - respiration
What are heterotrophs?
Organisms that build body mass by eating other organisms (secondary production)
What is aerobic respiration?
Respiration with the use of O2
What is anaerobic respiration?
Respiration without the use of O2
What are trophic levels?
They indicate how many feeding steps an organism is away from the autotroph level
What are decomposers?
Various bacteria that breakdown the dead organisms and waste materials, recycling their components
In what ways is energy lost through the trophic levels?
- respiration
- excretion of waste
What is a food chain?
Combination of trophic levels
What is a food web?
Multiple food chains woven together
What is usually the maximum amount of trophic levels in a food chain?
6
-Any more would require a large base of primary production
How many elements are considered essential for life?
24
What are macronutrients?
Elements required by all living things in large amounts
What are micronutrients?
Elements required in small amounts by all life or in moderate amounts by some forms of life
What are toxins?
Elements that are detrimental to living organisms
How can an element become a limiting factor?
It is not available at the right time, in the right amount or in the appropriate relative concentrations to each other.