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Chapter 9 Summary

Key Takeaways

  • Population ecology: Examines how populations change over time, focusing on population size, density, distribution, birth and death rates, and environmental interactions to understand species survival and adaptation.
  • Population size and density: These are influenced by birth, death, immigration, and emigration, and are typically estimated using sampling methods such as quadrant sampling and mark-recapture techniques due to practical constraints.
  • Species Distribution Patterns (Clumped, Uniform, and Random): These reveal important ecological interactions, such as resource availability, competition, and social behaviour, which influence survival and reproductive success.
  • Survivorship Curves (Types I, II, III): These illustrate species’ life history strategies, while r- and K-selection explain reproductive patterns ranging from high-output, low-care species to low-output, high-care species.
  • Exponential and Logistic Models: These describe population growth, with exponential growth showing unchecked increases and logistic growth incorporating environmental limits, stabilizing populations around carrying capacity.
  • Population Regulation: This is shaped by both density-dependent and density-independent limiting factors, such as competition, disease, predation, natural disasters, and climate, all of which interact to influence population dynamics and recovery potential.

OpenAI. (2025). ChatGPT. [Large language model]. https://chat.openai.com/chat
Prompt: Summarize the following content into six key takeaways.

Flashcards

Click on the flashcards to review key terms discussed in this chapter.

Text Description

Front of Card:

  1. Agricultural Revolution
  2. Age structure
  3. Biocapacity
  4. Biological control
  5. Carrying capacity (K)
  6. Clumped distribution
  7. Competition
  8. Conservation of endangered species
  9. Density-dependent limiting factors
  10. Density-independent limiting factors
  11. Ecological footprint
  12. Ecological overshoot
  13. Endangered species
  14. Exponential growth
  15. Immigration
  16. Interspecific competition
  17. Intraspecific competition
  18. Invasive species
  19. K-selected species
  20. Limiting factors
  21. Logistic growth
  22. Mark-recapture method
  23. Population density
  24. Population ecology
  25. Population size
  26. Quadrant sampling
  27. R-selected species
  28. Random distribution
  29. Species distribution
  30. Survivorship curve
  31. Sustainable resource management
  32. Type I survivorship curve
  33. Type II survivorship curve
  34. Type III survivorship curve
  35. Uniform distribution
  36. 3 types of species distribution
  37. 3 types of survivorship curves
  38. 2 types of life history strategies
  39. 2 types of population growth
  40. 2 types of limiting factors
  41. 4 applications of population ecology

Back of Card:

  1. A historical shift about 10,000 years ago when humans began farming and domesticating animals, leading to food stability and population growth.
  2. The distribution of individuals among age groups in a population; used to predict trends and plan for future needs.
  3. The Earth’s ability to regenerate resources and absorb waste over time.
  4. The use of predators, parasites, or pathogens to control pest species naturally and sustainably.
  5. The maximum number of individuals an environment can support based on resource availability.
  6. A pattern where individuals gather in groups, usually near resources.
  7. When organisms compete for the same limited resources, affecting population growth.
  8. Actions to protect species from extinction using legal protection, habitat restoration, and ecological strategies.
  9. Factors like disease or competition that intensify as population density increases.
  10. Factors like natural disasters that impact populations regardless of size.
  11. The land and water area required by a person or group to produce resources and absorb waste.
  12. Occurs when human consumption exceeds Earth’s ability to regenerate resources, causing environmental damage.
  13. Species at risk of extinction due to threats like habitat loss or disease.
  14. Population growth at a constant rate without limits, forming a J-shaped curve.
  15. The arrival of individuals into a population, increasing its size.
  16. Competition between different species for shared resources.
  17. Competition within the same species for limited resources.
  18. Non-native species that spread rapidly, harming ecosystems and economies.
  19. Species that grow slowly, produce few offspring, and invest in parental care; adapted to stable environments.
  20. Environmental conditions that restrict population size and growth.
  21. Growth that slows as resources become limited, stabilizing at carrying capacity; S-shaped curve.
  22. A method of estimating population size using captured, marked, and recaptured individuals.
  23. The number of individuals per unit area or volume.
  24. The study of population dynamics and interactions with the environment.
  25. The total number of individuals in a specific area at a given time.
  26. Estimating population size by counting individuals in small plots and scaling up.
  27. Species that reproduce quickly, have many offspring, and little parental care; suited for unstable environments.
  28. A distribution where individuals are spread randomly across a habitat.
  29. How individuals are spatially arranged in their habitat—clumped, uniform, or random.
  30. A graph showing how many individuals survive at each age level; Types I, II, and III.
  31. The practice of using natural resources in a way that maintains ecosystem health for future generations.
  32. Most individuals survive to old age (e.g., humans).
  33. Equal chance of dying at any age (e.g., birds).
  34. High death rate early in life, with survivors living long (e.g., fish, plants).
  35. Individuals are evenly spaced due to competition or territoriality.
  36. Clumped, uniform, and random.
  37. Type I, Type II, and Type III.
  38. r-selected and K-selected species.
  39. Exponential and logistic growth.
  40. Density-dependent and density-independent.
  41. Conservation of endangered species, sustainable resource management, invasive species management, and biological control.

OpenAI. (2025). ChatGPT. [Large language model]. https://chat.openai.com/chat
Prompt: Provide definitions for all the bolded terms in the shared content and list all the terms in alphabetical order.

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Biology Essentials 2 Copyright © by Kari Moreland is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.