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:
- Agricultural Revolution
- Age structure
- Biocapacity
- Biological control
- Carrying capacity (K)
- Clumped distribution
- Competition
- Conservation of endangered species
- Density-dependent limiting factors
- Density-independent limiting factors
- Ecological footprint
- Ecological overshoot
- Endangered species
- Exponential growth
- Immigration
- Interspecific competition
- Intraspecific competition
- Invasive species
- K-selected species
- Limiting factors
- Logistic growth
- Mark-recapture method
- Population density
- Population ecology
- Population size
- Quadrant sampling
- R-selected species
- Random distribution
- Species distribution
- Survivorship curve
- Sustainable resource management
- Type I survivorship curve
- Type II survivorship curve
- Type III survivorship curve
- Uniform distribution
- 3 types of species distribution
- 3 types of survivorship curves
- 2 types of life history strategies
- 2 types of population growth
- 2 types of limiting factors
- 4 applications of population ecology
Back of Card:
- A historical shift about 10,000 years ago when humans began farming and domesticating animals, leading to food stability and population growth.
- The distribution of individuals among age groups in a population; used to predict trends and plan for future needs.
- The Earth’s ability to regenerate resources and absorb waste over time.
- The use of predators, parasites, or pathogens to control pest species naturally and sustainably.
- The maximum number of individuals an environment can support based on resource availability.
- A pattern where individuals gather in groups, usually near resources.
- When organisms compete for the same limited resources, affecting population growth.
- Actions to protect species from extinction using legal protection, habitat restoration, and ecological strategies.
- Factors like disease or competition that intensify as population density increases.
- Factors like natural disasters that impact populations regardless of size.
- The land and water area required by a person or group to produce resources and absorb waste.
- Occurs when human consumption exceeds Earth’s ability to regenerate resources, causing environmental damage.
- Species at risk of extinction due to threats like habitat loss or disease.
- Population growth at a constant rate without limits, forming a J-shaped curve.
- The arrival of individuals into a population, increasing its size.
- Competition between different species for shared resources.
- Competition within the same species for limited resources.
- Non-native species that spread rapidly, harming ecosystems and economies.
- Species that grow slowly, produce few offspring, and invest in parental care; adapted to stable environments.
- Environmental conditions that restrict population size and growth.
- Growth that slows as resources become limited, stabilizing at carrying capacity; S-shaped curve.
- A method of estimating population size using captured, marked, and recaptured individuals.
- The number of individuals per unit area or volume.
- The study of population dynamics and interactions with the environment.
- The total number of individuals in a specific area at a given time.
- Estimating population size by counting individuals in small plots and scaling up.
- Species that reproduce quickly, have many offspring, and little parental care; suited for unstable environments.
- A distribution where individuals are spread randomly across a habitat.
- How individuals are spatially arranged in their habitat—clumped, uniform, or random.
- A graph showing how many individuals survive at each age level; Types I, II, and III.
- The practice of using natural resources in a way that maintains ecosystem health for future generations.
- Most individuals survive to old age (e.g., humans).
- Equal chance of dying at any age (e.g., birds).
- High death rate early in life, with survivors living long (e.g., fish, plants).
- Individuals are evenly spaced due to competition or territoriality.
- Clumped, uniform, and random.
- Type I, Type II, and Type III.
- r-selected and K-selected species.
- Exponential and logistic growth.
- Density-dependent and density-independent.
- 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.