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GENERAL ECOLOGY LEC > CHAPTER 6 Population Ecology > Flashcards

CHAPTER 6 Population Ecology Flashcards

1
Q

The way we measure additions of this type is with the natality rate (also called the birth rate)

A

BIRTH

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2
Q

This is the permanent arrival of new individuals into the population.

A

IMMIGRATION

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3
Q

This is the permanent movement of individuals out of a population.

A

EMIGRATION

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4
Q

We measure this with the mortality rate (also called the death rate).

A

DEATH

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5
Q

A group of individuals of the same species that live within a particular area and interact with one another.

A

population

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6
Q

The study population in relation to environment, including environmental influences density, distribution, age structure and abundance.

A

Population Ecology

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7
Q
  • In species that reproduce sexually, a population might be defined as the group of individuals that interact by _______.
  • In species that reproduce asexually, a population must be defined by other kinds of interactions, such as ____ for common sources of food.
A

interbreeding
competition

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8
Q
  • Population ____ the number of individuals in the population
  • Population ____ the number of individuals per unit of area.
A

size
density

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9
Q
  • geographic area where individuals of a species occur.
  • the number of individuals of a species that are found in a given area
A

distribution
abundance

Distribution and abundance change over time and space

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10
Q

Pattern of spacing of individuals within the boundaries of the population
** Clumped – most common
*Usually because of resources
*Humans
**Uniform
*Interactions between the individuals in the population
*Territoriality
** Random
*Inconsistent
*Plants – windblown seeds

A

dispersion

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11
Q

Population Growth Rate

BR
DR
M
AS
SC

A
  • Birth Rate - fecundity
  • Death Rate - mortality
  • Migration (immigration & emigration)
  • Age Structure
  • Survivorship Curves (patterns of mortality)
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12
Q

Relative number of individuals at each age group
Used to project future population growth
“pyramid” shaped

A

AGE STRUCTURE

Greater number of young individuals means greater potential for growth.

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13
Q

Survivorship Curves

Shows the number of individuals alive during each stage of life
Type I – few offspring
- _____ death rates at beginning of life
- _____ of parental care
Type II - _____ offspring
- _____ death rate at all age groups
Type III – lots offspring
- _____ death rates at beginning of life
- _____ parental care

A

Low
Lots
medium
Consistent
High
Little or no

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14
Q

describes populations that increase in numbers without any limits to their growth. (J-shaped curve)
-The per capita growth rate stays the same, making population grow faster as they gets larger.

A

Exponential growth

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15
Q

introduces limits to reproductive growth that become more intense as the population size increases. (S-shaped curve)

A

Logistic growth

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16
Q

increases continually without limiting factors – assumes resources are unlimited
The larger the population becomes the faster it grows
Unregulated growth
Occurs in populations that colonize a new or unfilled environment

A

exponential model

But realistically, populations cannot grow exponentially forever…
AS THE DENSITY CHANGES , IT HAS AN IMPACT ON COMPETION FOR FOOD RESOURCES.

17
Q

is anything that constrains a population’s size and slows or stops it from growing. Some examples of limiting factors are biotic, like food, mates, and competition with other organisms for resources.

refers to any of the factors (variables) in an environment capable of limiting a process, such as the growth, abundance, or distribution of a population of organisms in an ecosystem. —– may be density-dependent or density-independent.

A

Limiting factor

18
Q

2 Categories of limiting factors

Birth rate and death rate change with population size
The larger the population gets the more competition
Resources
Territoriality
Disease
Predation
Toxic waste (metabolic)
Intrinsic Factors

A

density-dependent factors

19
Q

2 Categories of limiting factors

Size of the population does not effect the birth rate or death rate
Natural disasters – will occur regardless of population size
Fire
Flood
Weather

A

density-independent factors

20
Q

Population Growth

  • account for limiting factors and limited resources
  • the number of individuals that can occupy the habitat (K)
A

logistic model
carrying capacity

21
Q

The per capita growth rate gets smaller as the population approaches carrying capacity (K)

A

logistic growth

22
Q

Reproductive Strategies - Selection

Maximum growth rate below carrying capacity
* Exponential growth
* Opportunistic populations
* Early reproduction
* Semelparity
* Short life span
* High mortality rate
* Little or no parental care
* Large numbers of offspring
Fish
Grasshoppers
Flies

A

r-selected

23
Q

Reproductive Strategies - Selection

Maximizes population size at or near carrying capacity
* Logistic growth
* Equilibrial populations
* Late reproduction
* Iteroparity
* Long life span
* Low mortality rate
* Lots of parental care
* Few offspring
Sharks
Elephants
Humans

A

k-selected

24
Q

Reproduction

Determined by the tradeoff between birth rate and survival probability
** ________ – 1 single large reproductive effort
* Harsh environments
* Low survival rate for long periods of time
* Insects, annual plants, salmon

** ________ – multiple smaller reproductive effort
* Occurs in organisms that survive for long periods of time once established
* Mammals, perennial plants

A

Semelparity
Iteroparity

25
Q

The larger the population gets, the faster it grows

The larger the population gets, the slower it grows

A

exponential growth J

logistic growth S

26
Q

Ecological Interactions between organisms

when two organisms of the same or different species attempt to use an ecological resource in the same place at the same time
ex.

  1. Monkeys compete with each other and other animals for food.’
  2. Rams compete with each other for mates.
  3. Until Americans introduced gray squirrels into parts of England in the early 20th century, red squirrels had been the only species of squirrel in the country. The gray squirrels were larger and bred faster and successfully competed for resources. Within a couple years of overlap in an area, the red squirrels disappeared.
A

Competition
Ex: food, water, shelter

27
Q

Ecological Interactions between organisms

the ecological niche involves both the place where an organism lives and the roles that an organism has in its habitat

A

niche

Example: The ecological niche of a sunflower growing in the backyard includes absorbing light, water and nutrients (for photosynthesis), providing shelter and food for other organisms (e.g. bees, ants, etc.), and giving off oxygen into the atmosphere.

28
Q

The ecological niche of an organism depends not only on where it lives but also on what it does. By analogy, it may be said that the habitat is the organism’s “—–”, and the niche is its “—–”, biologically speaking.

A

address
profession

29
Q

Ecological Interactions between organisms

one organism captures and feeds on another organism
1. —one that does the killing
2. —one that is the food

A

predation
Predator
Prey

30
Q

Ecological Interactions between organisms

any relationship in which two species live closely together

A

symbiosis

31
Q

Symbiosis

both species benefit (WIN-WIN)
Ex: insects and flowers

A

mutualism

32
Q

Symbiosis

one member of the association benefits and the other is neither helped nor harmed.
(WIN-0)
Example: barnacles on a whalel The Remora fish attaches to the shark and gets a free ride; Birds build nests in trees.

A

commensalism

33
Q

Symbiosis

one organisms lives on or inside another organism (host) and harms it.
The parasite obtains all or part of its nutritional needs from the host. (WIN-LOSE)
Example: fleas on a dog; Wasp eggs on back of caterpillar; Sea lampreys feed on fluids of other fish; Mosquito biting a human

A

parasitism

GENERAL ECOLOGY LEC (9 decks)

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