An Introduction To Ecology And The Biosphere Essay
An Introduction To Ecology And The Biosphere
1. Define ecology.
2. Describe the relationship between ecology and evolutionary biology. 3. Distinguish between abiotic and biotic components of the environment. 4. Distinguish among organismal ecology, population ecology, community ecology, ecosystem ecology, and landscape ecology. 5. Clarify the difference between ecology and environmentalism.
Interactions between Organisms and the Environment Limit the Distribution of Species 6. Define biogeography.
7. Describe the questions that might be asked in a study addressing the limits of the geographic distribution of a particular species. 8. Explain how dispersal may contribute to a species’ distribution. 9. Distinguish between the potential and actual range of a species. 10. Explain how habitat selection may limit distribution of a species within its range of suitable habitats. 11. Describe, with examples, how biotic and abiotic factors may affect the distribution of organisms. 12. List the four abiotic factors that are the most important components of climate. 13. Distinguish between macroclimate and microclimate patterns. 14. Explain, with examples, how a body of water and a mountain range might affect regional climatic conditions. 15. Provide an example of a microclimate.
16. Describe how an ecologist might predict the effect of global warming on distribution of a tree species. 17. Name three ways in which marine biomes affect the biosphere.
18. Define each layer in a stratified aquatic biome: photic zone, aphotic zone, benthic zone, abyssal zone. 19. Define the following characteristics of lakes: thermal stratification, thermocline, seasonal turnover. 20. Explain why the following statement is false: “ All communities on Earth are based on primary producers that capture light energy by photosynthesis.” 21. Describe the characteristics of the major aquatic biomes: lakes, wetlands, streams, rivers, estuaries, intertidal biomes, oceanic pelagic biomes, coral reefs, and marine benthic biomes.
22. Define a climograph. Compare the climographs of taiga, grassland, and desert biomes. 23. Describe the vertical layering of a forest and grassland. 24. Give an example of a biome characterized by periodic disturbance. 25. Describe the characteristics of the major terrestrial biomes: tropical forest, desert, savanna, chaparral, temperate grassland, coniferous forest, temperate broadleaf forest, and tundra. CHAPTER 53
Characteristics of Populations
1. Distinguish between density and dispersion of a population.
2. Explain how ecologists may estimate the density of a species.
3. Describe conditions that may result in clumped dispersion, uniform dispersion, and random dispersion of individuals in a population.
4. Explain how a life table is constructed.
5. Distinguish between a life table and a reproductive table.
6. Describe the characteristics of populations that exhibit Type I, Type II, and Type III survivorship curves.
7. Define and distinguish between semelparity and iteroparity. Explain what factors may favor the evolution of each life history strategy. 8. Explain, with examples, how limited resources and trade-offs may affect life histories.
9. Compare the exponential model of population growth with the logistic model. 10. Explain how an environment’s carrying capacity affects the per capita rate of increase of a population. 11. Explain the meaning of each of the following terms in the logistic model of population growth: a. rmax
b. K – N
12. Distinguish between r-selected populations and K-selected populations.
13. Explain how density-dependent and density-independent factors may affect population growth. 14. Explain, with examples, how biotic and abiotic factors may work together to control a population’s growth. 15. Describe boom-and-bust population cycles, explaining possible causes of lynx/hare fluctuations.
Human Population Growth
16. Describe the history of human population growth.
17. Compare the age structures of Italy, Afghanistan, and the United States. Describe the possible consequences for each country. 18. Describe the problems associated with estimating Earth’s carrying capacity for the human species. 19. Define the demographic transition.
20. Explain how an ecological footprint can be calculated for an individual or country. Describe the possible currencies of this calculation.
1. List the categories of interspecific interactions. Explain how each interaction affects the survival and reproductive success of the two species involved. 2. State the competitive exclusion principle.
3. Define an ecological niche and restate the competitive exclusion principle using the niche concept. 4. Explain how interspecific competition may lead to resource partitioning. 5. Distinguish between fundamental and realized niche.
6. Give specific examples of adaptations of predators and prey. 7. Explain how cryptic coloration and aposematic coloration may aid an animal in avoiding predators. 8. Distinguish between Batesian mimicry and Müllerian mimicry. 9. Describe how predators may use mimicry to obtain prey.
10. Give specific examples of adaptations of herbivores.
11. Distinguish among endoparasites, ectoparasites, and parisitoids. 12. Distinguish among parasitism, mutualism, and commensalism. 13. Explain why it is difficult to classify a symbiotic relationship as commensal.
14. Explain the relationship between species richness and relative abundance and explain how both contribute to species diversity.
15. Distinguish between a food chain and a food web.
16. Describe two ways to simplify food webs.
17. Summarize two hypotheses that explain why food chains are relatively short. Explain the experimental evidence that supports the energetic hypothesis.
18. Explain how dominant and keystone species exert strong control on community structure. Describe an example of each.
19. Explain how a foundation species may facilitate the survival and reproduction of other species.
20. Distinguish between the bottom-up and top-down models of community organization.
21. Describe the successful biomanipulation of Finland’s Lake Vesijärvi.
Disturbance and Community Structure
22. Define stability and disturbance.
23. Describe the intermediate disturbance hypothesis. Explain why moderate levels of disturbance may create conditions that foster greater species diversity than low or high levels of disturbance.
24. Distinguish between primary and secondary succession.
25. Describe how species that arrive early in succession may facilitate, inhibit, or tolerate later arrivals.
26. Describe the biotic and abiotic changes that have occurred during primary succession on glacier moraines in Glacier Bay, Alaska.
27. Describe an example of humans acting as agents of disturbance.
Biogeographic Factors Affect Community Biodiversity
28. Explain why species richness declines along an equatorial-polar gradient.
29. Explain the significance of measures of evapotranspiration to species richness.
30. Define the species-area curve.
31. Explain how species richness on islands varies according to island size and distance from the mainland.
The Effects of Pathogens on Community Ecology
32. Describe one terrestrial and one marine example of a pathogen that has altered the structure of the community in which it is found. 33. Define a zoonotic pathogen. Explain, with an example, how zoonotic pathogens may be controlled.
Physical Laws Govern Ecosystems
1. Describe the fundamental relationship between autotrophs and heterotrophs in an ecosystem. 2. Explain how the first and second laws of thermodynamics apply to ecosystems. 3. Explain how decomposition connects all trophic levels in an ecosystem.
Primary Production in Ecosystems
4. Explain why the amount of energy used in photosynthesis is so much less than the amount of solar energy that reaches Earth. 5. Define and compare gross primary production and net primary production. 6. Define and compare
net primary production and standing crop. 7. Compare net primary production in specific marine, freshwater, and terrestrial ecosystems.
Secondary Production in Ecosystems
8. Explain why energy is said to flow rather than cycle within ecosystems. 9. Explain what factors may limit primary production in aquatic ecosystems. 10. Describe an experiment that provided evidence that iron availability limits oceanic primary production in some regions. Explain how iron availability is related to nitrogen availability in these regions. 11. Explain why areas of upwelling in the ocean have exceptionally high levels of primary production. 12. Distinguish between each of the following pairs of terms: a. primary and secondary production
b. production efficiency and trophic efficiency
13. Explain why the production efficiency of a human is much less than the production efficiency of a mosquito. 14. Distinguish between a pyramid of net production and a pyramid of biomass. 15. Explain why aquatic ecosystems may have inverted biomass pyramids. 16. Explain why worldwide agriculture could feed more people if all humans consumed only plant material. 17. Explain the green-world hypothesis. Describe four factors that may act to keep herbivores in check.
The Cycling of Chemical Elements in Ecosystems
18. Explain why nutrients are said to cycle rather than flow within ecosystems. 19. Describe the four nutrient reservoirs and the processes that transfer the elements between reservoirs. 20. Name the main processes driving the water cycle.
21. Name the major reservoirs of carbon.
22. Describe the nitrogen cycle and explain the importance of nitrogen fixation to all living organisms. Name three other key bacterial processes in the nitrogen cycle. 23. Describe the phosphorus cycle and explain how phosphorus is recycled locally in most ecosystems. 24. Explain how decomposition affects the rate of nutrient cycling in ecosystems. 25. Describe how net primary production and the rate of decomposition vary with temperature and water availability. 26. Describe the experiments at Hubbard Brook that revealed the key role that plants play in regulating nutrient cycles.
Human Impact on Ecosystems and the Biosphere
27. Describe how agricultural practices can interfere with nitrogen cycling. 28. Describe the causes and consequences of acid precipitation. 29. Explain why toxic compounds usually have the greatest effect on top-level carnivores. 30. Describe how increased atmospheric concentrations of carbon dioxide are changing Earth’s heat budget. 31. Describe the causes and consequences of ozone depletion.
AND RESTORATION ECOLOGY
The Biodiversity Crisis
1. Distinguish between conservation biology and restoration biology. 2. Describe the three levels of biodiversity.
3. Explain why biodiversity at all levels is vital to human welfare. 4. List the three major threats to biodiversity and give an example of each.
Conservation at the Population and Species Levels
5. Define and compare the small-population approach and the declining-population approach. 6. Explain how an extinction vortex can lead to the extinction of a small population. Describe how a greater prairie chicken population was rescued from an extinction vortex. 7. Distinguish between the total population size and the effective population size. Explain why this distinction is crucial in determining the minimum viable population size. 8. Describe the basic steps that are used to analyze declining populations and determine possible interventions in the declining-population approach. Describe the case of the red-cockaded woodpecker to illustrate this approach. 9. Describe the conflicting demands that may accompany
Conservation at the Community, Ecosystem, and Landscape Levels 10. Explain how edges and corridors can strongly influence landscape biodiversity. 11. Define biodiversity hot spots and explain why they are important. 12. Explain why natural reserves must be functional parts of landscapes. 13. Define zoned reserves and explain why they are important. 14. Define restoration ecology and describe its goals.
15. Explain the importance of bioremediation and biological augmentation of ecosystem processes in restoration efforts.
16. Describe the process of adaptive management.
17. Describe the concept of sustainable development.
18. Explain the goals of the Sustainable Biosphere Initiative.
19. Define biophilia and explain why the concept gives some biologists hope.