Week 10 Friday Flashcards
what is the first law of thermodynamics?
energy cannot be created nor destroyed, but transformed.
what is the second law?
heat energy will move from a warmer system to a cooler one
what is the 10% rule?
the idea that energy is passed thru an ecosystem from one trophic level to the next, only 10% of the energy is passed on
why do food webs generally only have 3-5 levels?
higher levels would not be productive enough
what are the groups of organisms in trophic levels
primary producers, primary consumers, secondary consumers, e.t.c
influences of bottom up control
influences of physical and chemical factors
influences of top down control
influences of consumers
what determines whether a community is controlled from the top or the bottom?
the relative importance of predation and primary production
when is compensation more likely to happpen, and what does it do?
when many species are present at each trophic level and it blocks cascading effects
what is a green world (trophic level wise)
3 or 5 levels
what is a brown/blue world (trophic level wise)
2 or 4 levels
why are trophic dynamics still debated
- both top-down and bottom-up forces can play roles - but the forces they exert are not always equal or easy to see
- organism with a wide diet breadth and omnivores complicate understanding the extent of relationships and their interconnectedness
- a trophic cascade is blocked by the effects of compensation and within-level competition
- complex and diverse communities could limit the impact of trophic cascades
- even simple systems are not so simple