chapter_19

Created July 17, 2024 by Bryon Spicci

Chapter 19: Population and Community Ecology

19.1: Population Demographics and Dynamics

  1. The statistical study of populations is called _______________________, a set of mathematical tools used to describe populations and investigate how they change.
  2. What are life tables?

Population Size and Density

  1. Populations are characterized by their __________________ (total number of individuals) and their ________________________________ (number of individuals per unit area).

Estimating Population Size

  1. Briefly outline the two methods (quadrat and mark and recapture) for estimation of population size.

Species Distribution

  1.  A species distribution pattern is the _______________________________________________________
  2. List and explain the three distribution patterns of a population (random, clumped, and uniform) within a given area.

Demography

  1. Define demography -
  2. Life tables -
  1. Mortality rate -
  1. Survivorship curves –
  1. Type 1 curve –
  2. Type 2 curve –
  3. Type 3 curve –

19.2 Population Growth and Regulation

  1. Models of population growth
  1. Exponential growth –
  1. J-shaped growth curve –
  1. Birth rate (B) –
  2. Death rate (D) –
  3. Population growth = rN
  1. If r is positive, then the population is:
  2. If r is negative, then the population is:
  3. If r is 0, the  population size is __________________________ a condition known as  __________ ____________________ _________________.

Logistic Growth

  1. Define the logistic growth model of population growth. See the key terms at the back of this chapter.

Carrying Capacity and the Logistic Model

  1. Carrying capacity (K) –
  2. S-shaped curve –
  3. Intraspecific competition –

Examples of Logistic Growth

  1.  Give examples and explain logistic growth in microorganisms and sheep and seals.

Population Dynamics and Regulation

  1. What are some factors that can affect the carrying capacity of an environment from year to year?
  2. Population growth is regulated in a variety of ways:
  1. Density-dependent factors –
  2. Density-independent factors –

Density-dependent Regulation

  1. Explain how density-dependent regulation affected the population size of two different populations of wild donkeys.  Refer to figure 19.7 in your textbook.

Density-independent Regulation and Interaction with Density-dependent Factors

  1. Why would a population suffering mortality from a density-independent cause be able to recover differently than a sparse population?

Demographic-Based Population Models

  1. K-selected species –
  2. r-selected species –

19.3 The Human Population

  1. Describe the growth of the human population since 1000 AD and explain the consequences of such a growth rate. See Figure 19.9!

Overcoming Density-Dependent Regulation

  1. Explain how humans have become adept at overcoming density-dependent regulation of our population.

Age Structure, Population Growth, and Economic Development

  1. Age structure –
  1. Countries with rapid growth have a ___________________ shape in their age structure diagrams showing a preponderance of ___________________ individuals, many of whom are of _________________ age. This pattern is most often observed in _____________________ countries. Most individuals _________________ live to old age because of less than optimal conditions and there is a _____________ birth rate.
  2. Age structures of developed countries such as the United States, still have a ______________ structure, but with many fewer _________________ and _________________-________ individuals and a greater  proportion of ______________ individuals.  Other developed countries such as Italy  have ________________ population growth.

Long-Term Consequences of Exponential Human Population Growth

  1. What did Dr. Paul R Ehrlich write in his 1968 book The Population Bomb?
  2. One-child policy
  3. What could the world population size increase to in 2100?
  4. List another consequence of population growth.

19.4: Community Ecology

Predation and Herbivory

  1. Describe the predator-prey relationship.
  2. Explain how the cycling of snowshoe hare and lynx populations in Northern Ontario is an example of predator-prey dynamics.

Defense Mechanisms against Predation and Herbivory

  1. Explain why predation and predator avoidance are strong selective agents.
  2. Give examples of mechanical and chemical defenses in plants and animals to avoid predators and predation.
  1. Mimicry

Competitive Exclusion Principle

  1. State the competitive exclusion principal

Symbiosis

  1. Define symbiosis
  1. Commensalism –
  2. Mutualism –
  3. Parasitism –
  1. Host

Characteristics of Communities

  1. Biodiversity –
  1.  Species richness –
  2.  Biogeography –
  3.  Relative species abundance –

Foundation Species

  1. Foundation species –
  2. Keystone species –

Community Dynamics

  1. Environmental disturbances –
  1. Primary succession –
  2. Secondary succession –

Primary Succession and Pioneer Species

  1. Primary succession occurs when _________________________ is formed, for example following the eruption of volcanoes, such as those on the Big Island of Hawaii.
  2. Pioneer species –

Secondary succession

  1. Give an example of secondary succession.
  1. Climax community –
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