Exam 19: Species Diversity in Communities

Refer to the table. The table shows hypothetical data for a community of fungi. These data show that the community best fits the _______ model. Based on this, one would predict that the diversity of the community with a disturbance of 16 and a competitive displacement of 16 would have a diversity of _______.

Refer to the table. The table shows six species of bacteria with their population growth rates (per day) and competitive interaction strengths. Given the data, which assemblage of species would most likely fit the assumptions of the lottery model?

The failure of some non-native species to become incorporated into communities is often attributed to _______ (i.e., the phenomenon whereby interactions with native species exclude or slow the growth of non-native species).

Tilman experimentally manipulated plant species richness and measured total plant cover after two years. Which statement best describes the relationship between plant species richness and total plant cover that he observed?

Refer to the figures. Figure 1 Figure 2 You are evaluating three snail species to determine their overall threat as invasive species to an area. You bring several individuals of each species into your lab to test their tolerance of a range of abiotic and biotic factors. Figure 1 shows how the three snail species respond to differences in average temperature and Figure 2 shows the number of prey and parasite species for each of the species in the new areas, along with how competitive each potential invasive species will be in the new community (higher numbers indicate that the species will be a more successful competitor). -Based on a combination of both abiotic and biotic factors, which snail species pose(s) the greatest overall threat as an invasive species? Justify your answer.

Studies of various plants have shown that at low elevations, neighboring plants tend to affect the focal plant negatively, but in more stressful environments at those same elevations, they tend to affect the focal plant positively. This result is most consistent with the assumptions of

In the studies by Hacker and Gaines in a New England salt marsh, the presence of Juncus was shown to _______ species diversity, especially in the _______ intertidal zone.

Which statement about neutral models of species diversity is false?

Refer to the figure. Robert and John MacArthur found that in both tropical and temperate habitat, bird species diversity _______ as plant diversity increased and _______ as foliage height diversity increased.

What is the "paradox of the plankton"?

Which statement about the redundancy hypothesis, explaining the relationship between species diversity and community function, is false?

Refer to the table. The table shows the population growth rate (per day) and competitive interaction strengths of seven species of algae. Which assemblage of species would most likely fit the assumptions of the lottery model?

Consider two species in competition for shared resources, species 1 and species 2. If these species are coexisting, which statement must be true?

Refer to the table. The table shows hypothetical data for a community of fungi. These data show that the community best fits the _______ model. Based on this, one would predict that the diversity of the community with a disturbance of 16 and a competitive displacement of 16 would have a diversity of _______.

The algae Caulerpa taxifolia is native to warm tropical waters. However, a cold-tolerant strain was selectively bred for aquariums and as a result, it has become an invasive species in the Mediterranean where it grows in much colder water than its native range. Which of the following factors did humans have the greatest impact on?

Refer to the figure. Figure 8 You are studying a new area to determine how disturbances affect species diversity. You are now investigating the impact of species richness on community function.Answer the following questions: a) Create two graphs (this will be referred to as Figure 9) showing the predicted relationship between species richness and community function for (A) the complementary hypothesis, and (B) the redundancy hypothesis. Label your x- and y-axes. b) At which point, if any, could species richness decline without impacting community function? Circle this area on your graphs (this will be referred to as Figure 10). c) How would the predicted relationship change if species differed in their overall effect on community function? How might the removal of species affect community function in ways not predicted by your graph (Figure 9)?

According to the dynamic equilibrium model, species diversity is highest when disturbance is at _______ levels and competitive displacement is at _______ levels.

A grounds crew manager of a large park is tasked with guarding the land against invading species. He is aware that a certain weedy plant could not withstand average winter conditions in the area, but it could survive during a particularly mild winter. The most conservative conclusion the manager might come to about the risk of this plant as an invasive species is that the plant

Refer to the table. Similar to Tilman's studies of coexistence using diatoms, a research team is now examining competitive outcomes between two species of bacteria, A and B, which vary in how they use silica and phosphorus. The team manipulated both silica and phosphorus and examined whether bacteria A or bacteria B won the competition, or whether there was co-existence between the two species (denoted as outcome C). The results are shown in the table. From these results, the team concludes that

According to the concept of resource partitioning, which combination of attributes of a community would tend to lead to higher species richness?