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In a study led by Dave Tilman at the University of Minnesota, researchers measured a variety of parameters every year in grassland plots that had been planted with different species richnesses.  One year there was a severe drought.  The researchers compared the biomass of plants in the year following the drought to the biomass of the plants in the year preceding the drought and got the following data.  What are reasonable conclusions from these data? Choose “supported” or “not supported” for each statement.   *numbers in graph indicate how many plots had that number of species. Plots with high species richness (compared to those with very low species richness) had greater resistance to the effects of the drought on biomass. [ans2] The drought decreased species richness[ans3] If we assume that the species-rich plots are also higher in diversity, these data support the diversity-stability hypothesis[ans4]

According to the redundancy hypothesis, species are redundant if

Assuming they all have the same total size, which shape would most likely preserve the highest species richness?

A hot spot of endemism would have

Which of these predictions of the Equilibrium Model of Island Biogeography is least supported by evidence?

The amount of land needed to produce all the resources someone uses and to absorb all the CO2 they release through their choices is called their:

Equations discussed in Chapters 54 – 57: * = multiplication sign dn/dt = B – D dn/dt = b*N – d*N r = (b-d) dn/dt = r*N dn/dt = r*N * ((K-N)/K) Ro = sum (lx * mx) Nt = No * Rot r*B > C Ppersist = 1−E+(M*(1−E)) Pregional = 1−(Pextinct A * Pextinct B * Pextinct C * Pextinct D) Where Pextinct = 1−Ppersist lx = nx/no Nt+1 = Nt*Ro Nt = No*Rot

Briefly explain the phenomenon of territoriality and provide an example of a signal an animal can use to designate a territory. Then explain one advantage and one disadvantage to the organism maintaining a territory.  Finally, explain how territorial behavior typically influences population dispersion at the landscape level. 

A) A team of ecologists is studying a population of snails in a marsh. During the first sampling, they capture and mark 120 snails before releasing them back into the population. A week later, they recapture 150 snails, 30 of which are marked. Calculate the size of the snail population. (Need to show calculations to receive full credit). B) After carefully observing the recaptured animals, the researchers discovered that 10% of the marked snails actually lost their marks during the study period. Adjust the population estimate to account for this mark loss. Hint: The true number of marked snails in the second sample (R′) can be recalculated as: R′=R/(1−Mark Loss Rate). (Need to show calculations to receive full credit).

A metapopulation of frogs is distributed across five ponds. Data on local extinctions and recolonizations are presented below: Pond Local Extinction Events (5 years) Recolonization Events (5 years) 1 2 2 2 3 1 3 0 0 4 5 4 5 1 1 Which pond is most at risk of permanent extinction and why?