Food Webs
Greatest source of biological energy and biomass in terrestrial ecosystems
Producers
Which side has a higher species evenness?
Left side
This graph shows what ecological hypothesis?
Intermediate disturbance hypothesis
How do you calculate Net Primary Productivity?
NPP = GPP - CO2 lost to respiration
A feeding strategy in which a consumer feeds at multiple trophic levels
Omnivory
Species that have a disproportionately large impact on community structure relative to their abundance or biomass
Keystone species
Which circle(s) has the greatest alpha/α diversity?
A and B
What are at the three reasons why tropical environments support more species?
–Greater solar radiation and precipitation leads to greater plant productivity
–Less seasonal variation in temperature and precipitation
–Longer periods of evolutionary time without major climatic disruption (e.g., glaciation)
What are the three stages of ecological succession?
Pioneer, intermediate, climax
What is the difference between decomposers and detritivores?
Decomposers = bacteria and fungi
Detritivores = animals
Where are the majority of federal conservation lands in the United States?
West
According to the graph, which environment (tropical/temperate) has more specialists?
Tropical
This graph shows that WHAT two things limit productivity?
Nitrogen, phosphorus
In a fire-suppressed forest, what is the most intense type of forest fire?
Tree crown fires
What scientist(s) found that: the arrival of a top predator (killer whales) dramatically reduced the abundance of a keystone predator (sea otters) which increased the abundance of herbivores (sea urchins). Sea urchins subsequently reduced total kelp density.
Estes et al. (1998)
The "rivet" model of ecological function (Ehrlich & Ehrlich 1981) predicts WHAT?
As species richness increases, functional overlap/redundancy increases
What are the two reasons why there are more folivorous (leaf-eating) insects in the tropics than in temperate forests?
1. Greater host plant diversity in the tropics
2. Greater host specificity/niche specialization in the tropics
1. Reduces biodiversity & ecosystem function
2. May lead to a build-up of fuel for more intense and destructive wildfires
What is an example of a nature-based solution with a top-down approach?
Trophic rewilding
What is the connectivity (C) of this food web?
C = 2(# of links)/(S(S-1))
C = 2(7)/(6)(5) = 0.47
How would you calculate the β diversity between sites C and D?
β = 2Sb / (S1 + S2)
β = 2(6) / (9 + 6) = 0.80
High species diversity should decrease what, and increase what?
1. Decrease the stability of individual populations of species within a community
2. Increase the stability of communities as a whole
What type of succession followed glacial retreat in Glacier Bay, Alaska?
Primary succession
In the ball-in-cup model of alternative stable states, parameters are represented by WHAT?
The shape of the cup