Exam 3. Principles of Ecology. April 14, 2010. Name Directions: Perform beyond your abilities. There are 100 possible points (+ 9 extra credit pts) t N t = N o N t = N o e rt N t+1 = N t + r o N t (1-N t /K) N t = K/(1 + [(K N o )/N o ] * e rt ) dn/dt = rn(1-n/k) N captured and marked initially = N marked at recapture N total N total recaptured ds/dt = -BSI - ds di/dt = BSI vi di - I dr/dt = vi dr - gr dv/dt = rv cvp dp/dt = acvp dp N e = 1/((1/(4*N f ))+(1/(4*N m ))) dn 1 /dt = r 1 N 1 (K 1 N 1 12N 2 ) dn 2 /dt = r 2 N 2 (K 2 N 2 21N 1 ) H = - (p i * ln(p i )) J = H /H max = H /ln(n) dp/dt = cp(1-p) - ep Provide precise descriptions of the four, easily observed characteristics of natural selection. (5 pts, -2 for first missed) a. see syllabus b. c. d. Multiple guess. (5 pts each, 55 pts total) 1. The standard metapopulation model (seen above) provides the important equilibrium for the proportion of occupied patches. This relationship is which of the following? a. e = 1/c b. p = c/e 1 c. p = 1 c/e d. p = 1 e/c e p = e - c 2. Key factor analysis provides which of the following? a. A quantitative estimate of the importance of different resources affecting growth rates. b. A quantitative determination of which of two species is more of a keystone species. c. A measure of which life stage is most important within a species. d. A measure of the trophic level for a species. e. All of the above. 3. We discussed the effect of a keystone beetle on a meadow from research conducted at Cornell. The beetle was a specialist on the dominant species goldenrod (seen in the photo on the right). In the experiment the beetle was removed with a pesticide. The expected effect on the plant community of removing the beetle should be (and was found to be) a. an increase in H b. a decrease in H c. no change in H d. a decrease in H and an increase in J e. an increase in H and a decrease in J Principles of Ecology, Exam #3 Page 1 of 7
4. Given the transition matrix to the right and an initial community as below (the number of trees of each of the four species) then the composition of the forest in the next time step is best approximated by which of the following? GB = 10, BG = 20, RM = 30, B = 40 GB BG RM B a. 0.7 19.6 27.7 52 b. 1.5 27 33.25 38.25 c. 1.2 21.8 27.2 49.8 d. 2.3 34.4 38.8 24.5 e. 10 20 30 40 5. A stream is sampled for the diversity of aquatic insects. The researcher finds the following numbers of individuals from six species. The research team hires you to quantify this for them. Which choice below is correct and you become a quantitative guru in their eyes? (Use natural logarithm, base e. ) comm = c(1, 7, 3, 14, 22, 51) # as one might code it in R. Richness H a. 6 0.56 b. 6 1.3 c. 5 0.80 d. 6 1.45 e. 75 1.45 6. Species can be rare for a variety of reasons. According to the work of Deborah Rabinowitz which of the following is not a factor that we would use to define rarity? a. The range of a species. b. The tolerance of a species to different habitats. c. The size of the local population. d. Environmental heterogeneity where the species lives. e. None of the above they are all factors affecting rarity according to Rabinowitz. 7. In the food web to the right the arrows represent the movement of energy from one species to another (so this is an energy food web). Which species would most likely represent modern humans? a. species a. b. species m. c. species k. d. species h. e. species i. 8. Which of the following is consistent with the Janzen-Connell hypothesis? a. Seedling survival is positively related to distance from the parent tree. b. Seedling mortality is positively related to distance from the parent tree. c. Seedling survival is negatively related to distance from the parent tree. d. Birds disperse most seeds away from parent trees and are, therefore, rare under parent trees. e. All of the above are components of the Janzen-Connell hypothesis. Principles of Ecology, Exam #3 Page 2 of 7
9. The data depicted in the graph to the right, from a paper by Dave Tilman in 1994, suggest what? a. The data are a counter-example to the intermediate disturbance hypothesis. b. The data are consistent with the intermediate disturbance hypothesis. c. The data suggest that increasing diversity decreases community stability. d. The data suggest that increasing diversity increases community stability. e. none of the above. 10. Which of the following is consistent with regulation of trophic levels as described by Hairston, Smith, and Slobodkin (1960)? Assume that we have plants (I), herbivores (II), and predators (III). a. I (herbivory), II (competition), III (predation). b. I (competition), II (predation), III (predation). c. I (competition), II (competition), III (competition). d. I (competition), II (predation), III (competition). e. I (competition), II (competition), III (predation). 11. If a community develops in a way that is indistinguishable from random, this would be most consistent with which of the following models? a. Relay floristics (Clements). b. Initial floristics composition (Egler). c. Tolerance (Connell and Slatyer). d. Transition matrix model (Horn) e. Neutral theory (Hubbell). SECTION II CHOOSE THREE OF THE FOLLOWING FIVE (30 pts). Place and X on questions you don t want graded, otherwise I might be forced to choose. 1. Answer the following questions regarding the graph. a. Describe the mathematical model that is represented by this graph? (4 pts) Logistic growth b. The graph is clearly missing something important (that we discussed). What is it? (3 pts) equilibrium at N = 0 c. The graph has a second problem, represented by the circled arrow. What s wrong with that arrow, which is something you wouldn t do in your ecology textbook? (3 pts) Population density (x-axis) is actually decreasing. Principles of Ecology, Exam #3 Page 3 of 7
2 Krebs defined conservation biology as The applied ecology of endangered species. Identify two important shortcomings of this definition that we discussed in class. (5 pts ea.) a. Can be theoretical b. Not just endangered species studied by conservation biologists 3. Describe three ways to determine the role a species plays in a food web. (+3, +6, or +10 pts) a. Look at gut contents b. Watch what it eats for a really long time c. Use isotope ratios 4. You are interested in introducing a biological control agent to reduce the abundance of a pest species. a. Briefly discuss which of the graphs below (left of right) would be most favorable for a success control program? (6 pts) The one on the left because after driving the pest extinct the introduced predator would then go extinct. b. According the model you have chosen, describe the outcome for both species? (4 pts) kaboom! Extinct Principles of Ecology, Exam #3 Page 4 of 7
5. Identify three main results from this set of data. (-4 pts for first wrong, -3 thereafter) a. positive slope means increasing levels of NPP lead to increased consumption b. slopes are similar c. the relationship (intercept) is higher for aquatic ecosystems. SECTION III - CHOOSE ONE OF THE FOLLOWING THREE (10 pts) 1. Using the axes below provide a theory graph of the keystone species concept, relating the relative effect of a species on a community as a function of the relative biomass of species. (2 pts each for axis labels and approximate units; 6 pts for the correct relationship) (this is from lecture and your textbook) Principles of Ecology, Exam #3 Page 5 of 7
2. Provide two graphs. On the left the theory representing the intermediate disturbance hypothesis (axes = 1 pt ea., 3 pts for relationship). On the right provide a graph of data (real or plausible) that are consistent with the intermediate disturbance hypothesis (axes = 1 pt ea., 3 pts for relationship). 3. Provide two data graphs (approximate the data). On the left graph the relationship for bird species richness and altitude and on the right graph the relationship for bird species richness and latitude over the range of latitudes in the western hemisphere (N. and S. America). Be sure to label your axes and include approximate, reasonable scales (1 pt ea.) and include the data (3 pts for each graph). Principles of Ecology, Exam #3 Page 6 of 7
Extra Credit (9 possible pts) 1. Bindi Erwin is starring in what upcoming movie that you won t want to miss? (2 pts) 2. If an alien were to abduct you a. what have I repeatedly suggested they would ask you (discussed in lecture)? (2 pts) b. what would you correctly answer? (2 pts) 3. As discussed in what s new? this past Monday explain why conserving birds may slow global warming. (2 pts) 4. Have you used R ever outside of Principles of Ecology for any reason? Check only one answer. Yes, for this reason: (+ 1 pt) No, but assume I will. (+ 1 pt) No, and plan to NEVER use it again! (+ 1 pt) Principles of Ecology, Exam #3 Page 7 of 7