Exam 17: Change in Communities

Refer to the figures. Figure 1 Figure 3 You are studying two islands (Figure 3) that have recently experienced volcanic activity. Both were formerly forested with palm trees. On island 1, a heat wave resulting from the volcanic eruption leads to the destruction of all the above-ground vegetation (middle figure). On island 2, a lava flow resulting from the volcanic eruption (right figure) completely covers the island.Answer the following questions: a) How have the resources, environmental conditions, and species communities likely changed on the two islands as a result of the volcanic eruption? b) Assume that the frequency of eruptions on the islands follows the pattern shown in Figure 1. Using data from Figures 1 and 3, create a graph (this will be referred to as Figure 4) using the frequency of eruptions to show where island 1 and island 2 would be located on the spectrum of disturbance. The x-axis should be frequency and the y-axis should be intensity. c) Based on the frequency and intensity of the eruptions you plotted in Figure 4, what type of successional response would you predict for each island?

The tolerance and the inhibition models of primary succession hold different assumptions about the

Which statement about Bertness and Shumway's studies of succession in a New England salt marsh is true?

The inability of a system to shift back to the original community state, even after the original conditions have been restored, is called

Which statement best summarizes Elton's views on succession?

Refer to the figures. Figure 5 Figure 6 Figure 7 You are studying the impacts of a volcanic eruption that produces a lava flow that covers part of a grassland (Figure 5). You begin taking samples as soon as the area is safe to work in-about one year after the main eruption has ended. You set up a transect (beginning at "Transect start" in Figure 5), and then collect data on how several abiotic and biotic factors vary across it (Figures 6 and 7). -As part of your long-term research, you look into the succession patterns along the transect. Would a space for time substitution allow you to predict succession patterns in the lava flow area based on succession you observe in the blast zone? Why or why not? How is this situation similar or different from other situations that use space for time substitutions?

A region that is experiencing very frequent disturbances of intermediate intensity will most likely exhibit _______. If the intensity of these disturbances increases noticeably, the region will most likely exhibit _______.

In the succession that followed the eruption of Mount St. Helens, which organism played an important role as an ecosystem engineer?

Farrell's studies of intertidal communities along the Oregon coast demonstrated that

Refer to the figure. Suppose you are studying succession patterns in two species, species A and species B, both small aquatic organisms that colonize bare surfaces underwater. You replicated Sutherland's experiments in this new system by placing bare tiles underwater in predator-protected areas and areas with predators. You collect data on the percent of cover for each species, as shown in the figure. - Based on the data, what would you expect that a newly colonized area in a natural pond would look like?

Which type of succession involves colonization of habitats devoid of life?

Refer to the figure. On Mount St. Helens, the intensity of disturbance ranged from extremely high (lava dome, pumice plain) to moderate (mudflow zone, blowdown zone), to low (scorch zone). -In which area is the biotic stress of competition most likely to control succession?

Sousa's studies of southern California boulders showed that algal succession is driven predominately by

Alternative stable states most often arise

In his studies of succession in Glacier Bay, Chapin found that as communities went from early to latter stages of succession, soil moisture _______ and nitrogen _______.

Suppose late succession plants that are surrounded by early succession plants grow at a rate of 0.7 cm per day. If the early succession plants are removed experimentally, the late succession plants are observed to grow at a rate of 0.6 cm per day. This experiment shows that the early succession plants have a _______ effect on the late succession plants, and this observation is most consistent with the _______ model of succession.

A forest community has reestablished itself after an ice storm damaged most, but not all, of the trees in one area. Which type of succession best describes the reestablishment of the community after the storm?

Which principle is best supported by the results of Sutherland's studies in which fish predators were excluded from a marine fouling community?

Refer to the figure. The figure shows examples of possible disturbance intensity (y-axis) and frequency (x-axis) combinations. - What type of disturbance would be likely represented by B?

Which early ecologist maintained that plant communities are analogous to "superorganisms"?