Diversity and Trophic structure Flashcards
what does 1km squared of rainforest contain?
- 400 plant species
- 200 tree species
- 30 mammal species
- 100 bird species
- 25 reptile species
How can we quantify diversity?
Richness and evenness
How else can diversity be described?
As a species rank abundance curve
Species rank is dependent on?
relative abundance
Trophic structure is the…?
the feeding relationship between organisms form an important structural property of an ecological community
Feeding/trophic relationships =
food chains
Is energy transfer between trophic levels efficient?
No, it’s inefficient
Roughly 10% of biomass in one trophic level becomes biomass in the next
Interlinked food chains =
Food webs
Food webs consist of:
- many species each level
- highly complex
- many species feed at multiple trophic levels
- many feeding relationships change over time
- Food webs are usually short
2 main explanations of food webs:
The energetic hypothesis
The dynamic stability hypothesis
Energetic hypothesis =
Inefficient transfer between trophic levels means that food chains are inevitably short
Dynamic stability hypothesis =
- Long food chains less stable than short
- More likely to go extinct at a higher trophic level
- Population fluctuations at lower trophic levels are magnified at a higher trophic level
Most studies support which hypothesis?
Energetic hypothesis
Why can’t big things survive off of small things?
Because of the cost of capturing multiple small things
