Lecture 28 - Ecosystems Flashcards
1
Q
ecosystem
A
- > community(ies) + environment
- > area not necessarily large, just distinct
2
Q
how is energy and matter conserved within an ecosystem
A
- energy flow
- > requires continuous input
- > budget sums inputs and losses - matter flows and cycles
- > most is cycled
- > budget sums cycling, inputs and losses
*budgets help us understand how we impact ecosystems*
3
Q
Explain energy and nutrient cycling within an ecosystem
A
4
Q
explain the trophic levels of an ecosystem
A
Trophic levels: based on nutrition and energy relationships
Primary producers
- > autotrophs (photo or chemo)
Primary consumers
- > eat producers (herbivores)
Secondary or higher consumers
- > eat other consumers or detritivores (carnivores)
5
Q
GPP
A
Gross primary production
- > the total amount of photosynthesis (or chemosynthesis) per unit area and time
6
Q
NPP
A
Net primary production
NPP = GPP - Ra
- > NPP represents amount of energy and nutrients available to consumers
- > Ra produces use some energy for themselves
7
Q
Production Efficiency
A
assimilated energy stored as growth
- > heterotrophic efficiencies = ~10%
- > primary consumers = ~50% ingested primary productivity, passes ~50% as feces
8
Q
Different ways to show net productivity
A
- Energy pyramid
- Biomass pyramids
9
Q
Limiters of NPP
A
Terrestrial
- > temperature and water
Oceans
- > light and nutrients
10
Q
global NPP
A
