Skip to main content
Pearson+ LogoPearson+ Logo
Ch. 54 - Biodiversity and Conservation Ecology
Freeman - Biological Science 8th Edition
Freeman8th EditionBiological ScienceISBN: 9780138276263Not the one you use?Change textbook
All textbooksFreeman 8th EditionCh. 54 - Biodiversity and Conservation EcologyProblem 9
Chapter 54, Problem 9

The population size of mountain pine beetles in the American Northwest has long been held in check by freezing temperatures during the winters. As winters warm, populations of pine beetles are increasing, killing whitebark pine forest. Grizzly bears rely on the nuts of whitebark pine trees. Do you think climate change is affecting the fitness of the grizzly bear population?


a. No, because climate change is affecting the beetles, not the bears.
b. Yes, because climate change is decreasing the food supply of the bears, which means they will be less strong.
c. Yes, because climate change is decreasing the food supply of the bears, which is likely to reduce their ability to survive or reproduce.

Verified step by step guidance
1
Identify the key components of the problem: climate change, mountain pine beetles, whitebark pine trees, and grizzly bears.
Understand the relationship between these components: Warmer winters lead to increased pine beetle populations, which in turn kill more whitebark pine trees.
Analyze the impact on whitebark pine trees: As the number of these trees decreases, the availability of their nuts, a food source for grizzly bears, also decreases.
Consider the definition of biological fitness, which includes an organism's ability to survive and reproduce in its environment.
Evaluate how the reduced availability of a key food source (whitebark pine nuts) due to climate change could affect the grizzly bears' ability to survive and reproduce, thus impacting their fitness.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
1m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Climate Change and Ecosystem Dynamics

Climate change refers to long-term alterations in temperature and weather patterns, which can significantly impact ecosystems. In this context, warming winters allow mountain pine beetle populations to thrive, leading to the decline of whitebark pine trees. This shift in the ecosystem can have cascading effects on species that depend on these trees, such as grizzly bears, highlighting the interconnectedness of climate factors and biological communities.
Recommended video:
Guided course
03:36
Pollution and Climate Change

Food Supply and Animal Fitness

Animal fitness is defined as an organism's ability to survive and reproduce in its environment. A stable food supply is crucial for maintaining the health and reproductive success of a species. In the case of grizzly bears, the decline of whitebark pine due to beetle infestations reduces their food sources, which can lead to decreased strength, survival rates, and reproductive success, ultimately affecting the population's fitness.
Recommended video:
Guided course
10:26
Animal Physiology and Fitness Trade-Offs

Trophic Interactions

Trophic interactions describe the feeding relationships between organisms in an ecosystem, often illustrated through food webs. Grizzly bears are primary consumers that rely on the nuts of whitebark pine trees, which are affected by the population dynamics of mountain pine beetles. Changes in one trophic level, such as the decline of a food source, can disrupt the entire food web, impacting the health and viability of dependent species like the grizzly bear.
Recommended video:
Guided course
04:25
Interspecific Interactions
Related Practice
Textbook Question

Biologists claim that the all-taxa survey now under way at the Great Smoky Mountains National Park in the United States will improve their ability to estimate the total number of species living today. Discuss the benefits and limitations that this data set will provide in understanding the extent of global biodiversity.

Textbook Question

Some biologists prefer to focus efforts on preserving endangered species while others prefer to focus on preserving ecosystems. What is your advice to biologists, based on the evidence?

Textbook Question

Explain why the construction of wildlife corridors can help maintain genetic diversity in a fragmented landscape.

Textbook Question

The maps shown here chronicle the loss of old-growth forest (more than 200 years old) that occurred in the United States. In your opinion, under what conditions is it ethical for conservationists who live in the United States to lobby government officials in Brazil, Indonesia, and other tropical countries to slow the rate of loss of old-growth forest?

Textbook Question

Do you drink coffee? A lot of people do—coffee is a major tropical crop, valued at over \$100 billion per year. The most popular species of coffee, Coffea arabica, originated in Africa and is now planted extensively in Central and South America. The pest called the coffee berry borer beetle (Hypothenemus hampeii) moved along with the coffee and is a major problem for coffee farmers, sometimes destroying half of the coffee crop in mature plantations.

Based on what you have learned in this chapter about global trends in terrestrial ecosystems, what is currently the largest threat to the wet tropical forests in Central America?

a. Habitat destruction, such as the clearing of forests for coffee plantations

b. Exotic species, such as the introduction of coffee berry borers

c. Pollution, such as the use of pesticides in coffee plantations

d. Climate change, such as changes in precipitation patterns