Write your answers in the spaces provided. Refer to the figure or diagram to answer the question. Where explanation or discussion is required, support your answers with relevant information and/or specific examples. Invasive species are a global threat because they can outcompete many native species and lower the biodiversity of entire ecosystems.
(a) Maintaining high global biodiversity is important to provide ecosystem services to humans. Describe one cultural ecosystem service provided by diverse ecosystems.
(b) Kudzu is an invasive plant species that has been spreading in the United States at a rapid rate. First introduced in 1876, the plant was widely used to prevent soil erosion. The leaves of the plant have the ability to fix atmospheric nitrogen, which can supply the plant with nitrogen in nitrogen-poor soils. The plants have high rates of photosynthesis, and the vines can grow over other plant species, including trees and shrubs.
State Percent of Counties with Kudzu Reported Average Number of Kudzu in Counties with Reported Kudzu
New York 16% 2−10 plants
Pennsylvania 19% 2−10 plants
New Jersey 71% 2−10 plants
Maryland 46% 2−10 plants
Virginia 74% 2−10 plants
North Carolina 100% 11−100 plants
South Carolina 87% 11−100 plants
Georgia 100% 11−100 plants
Florida 61% 2−10 plants
Alabama 100% 101−500 plants
Mississippi 94% 101−500 plants
(i) Based on the data in the graph, identify the average growth rate of Kudzu at 20°C.
(ii) Based on the data in the graph, describe the relationship between temperature and growth rate for Kudzu.
(iii) Kudzu was first introduced in the United States in Philadelphia but has spread throughout parts of the United States. Using the data in the table and in the graph, explain how kudzu has successfully invaded parts of the United States.
(c) The silver carp is another species native to Asia that was introduced to aquaculture operations and sewage treatment ponds in the Mississippi River valley to control excess algae accumulation. The species escaped from these operations into the Mississippi River and its tributaries and has the potential to invade the Great Lakes. Scientists are concerned that this species is having severe negative impacts on these areas.
(i) Propose a potential solution, other than physically removing the carp from the rivers, to manage the problem of the invasive silver carp in the United States.
(ii) Describe one disadvantage or unintended consequence that could result from a solution aimed to control the silver carp populations in the United States.
(d) Identify a major threat to biodiversity, other than invasive species.
(e) The threat from invasive species can lead to individual species being classified as endangered and eventually going extinct.
(i) Some species are more vulnerable to extinction than others. Describe one characteristic of a species that would make it more vulnerable to extinction than others.
(ii) Describe an environmental problem that can result in an ecosystem after a species extinction.
(iii) Many ecologists argue that establishing large preserves is the single best strategy for preventing an endangered species from becoming extinct. Justify this strategy by explaining an additional benefit, other than preventing the endangered species from becoming extinct.