Campbell and Reece Chapter 52 Flashcards
(87 cards)
1
Q
Ecology
A
study of how living organisms and the physical environment interact in an immense and complicated web of relationships
2
Q
Biotic
A
interactions among organisms
3
Q
Abiotic
A
organisms and non-living, physical environment
4
Q
Examples of abiotic factors
A
- Precipitation
- Temperature
- pH
- Wind
- Chemical nutrients
5
Q
Environmental science
A
study of human interaction with the environment
6
Q
Levels of organization
A
Species < Population < Community < Ecosystem < Landscape < Biosphere
7
Q
Population
A
Group consisting of members of the same species that live together in a geographical area
8
Q
What characterizes populations?
A
- Population density
- Population dispersion
- Natality/Mortality rates
- Growth rates
- Survivorship
- Age Structure
9
Q
Populations have _____ than communities
A
different properties
10
Q
Population ecology
A
the number of individuals of a particular species in an area and the dynamics of that population
11
Q
What do population ecologists study?
A
- Common processes
- Interactions with environment
- Competition for resources
- Limiting factors
12
Q
population dynamics
A
study of changes in populations
13
Q
What is studied in population dynamics?
A
- Reproductive success or failure
- Evolution
- Genetics
- Effect on normal communities/ecosystems
14
Q
Population density
A
number of individuals of specie per unit of area or volume at a given time (may vary from season to season)
15
Q
Dispersion
A
characteristic spacing of species relative to one another
16
Q
Three types of dispersion
A
- random
- clumped
- uniform
17
Q
Random dispersion
A
occurs when individuals in a population are spaced throughout an area in a manner that is unrelated to the presence of others
18
Q
Clumped dispersion
A
concentrated individuals
19
Q
Uniform dispersion
A
evenly spaced
20
Q
Pros of clumped dispersion
A
- Social animals derive benefits from association
- fish schooling to deter predators
21
Q
Cons of clumped dispersion
A
- patchy distribution of resources
- limited seed dispersal or asexual reproduction (plants)
22
Q
What are changes in population size defined by?
A
Natality
Mortality
Dispersal
23
Q
Natality
A
birth rate
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Q
Mortality
A
death rate
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Dispersal
movement of individuals among populations
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Immigration
individuals enter population increasing size
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emigration
individuals leave population decreasing size
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Intrinsic rate of increase
maximum growth rate a population could sustain considering limiting factors
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Factors that determine growth rate
- fraction of life span when reproductive
- age where reproduction begins
- number of reproductive periods per lifetime
- number of offspring from each period
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Generally, ___ species have __ intrinsic rates while ___ species have ____ intrinsic rates
large-low, small-high
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How is intrinsic value displayed?
exponential curve
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Carrying capacity (K)
largest population that can be maintained for an indefinite period by a given environment
33
Logistical population growth
curve is graphed as an "S" curve once limits are reached
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two types of limiting factors
density-independent
| density-dependent
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Density-independent
factor is not altered by population density
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Examples of density-independent
Frost, blizzard, hurricane
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Density-dependent
factor is altered by population density
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Effects of density-dependent
- negative feedback system
- affects large proportion of population
- raises or lowers natality/mortality
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Examples of density-dependent
Predation, disease, competition
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Competition
interaction among two or more individuals that attempt to use the same essential resource
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Examples of resources that lead to competition
Food, water, sunlight
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Four types of competition
- intraspecific
- interspecific
- interference competition
- exploitation competition
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Intraspecific competition
competition within population
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interspecific competition
multiple populations
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interference competition (contest)
dominant individuals overtake limited resources of other individuals
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Exploitation competition (scramble)
resources are shared so at high population densities none of them obtains enough
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Semelparous
species that expend energy in a single, immense reproductive effort
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Examples of semelparity
agaves, pacific salmon
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Iterparous
exhibit repetitive reproductive cycles
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Examples of iteroparity
vertebrates, perennial herbaceous plants, shrubs, trees
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How does timing affect iteroparity?
Early- not enough energy for growth
| Late- no opportunity for multiple cycles
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Fecundity
potential capacity to produce offspring
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Fitness
ability of an organism to reproduce successfully
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r strategists
high per capita growth rate
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specs of r strategists
- Small body size
- Early maturity
- Short life span
- Large broods
- Little parental care
- Found in variable, opportunistic habitats
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examples of r strategists
mosquitoes and dandelions
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k strategists
maximize chances of survival
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specs of k strategists
- Do not produce large numbers of offspring
- Large body size
- Slow development
- Long life spans
- Late reproduction
- Low reproductive rate
- Found in stable environments
- Parental care
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Life table
shows mortality and survival data of population or cohort
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Cohort
a group of individuals at the same age
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Survivorship
probability that an individual in a population or cohort will survive to a given age
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survivorship curve
logarithm based graph that displays the number of survivors over time
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type I survivorship curve
younger cohorts and reproductive ages have highest probability of survival
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type II survivorship curve
all cohorts have the same mortality rate
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type III survivorship curve
older cohorts have higher chance of survival
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landscape
natural heterogeneous landscape consisting of interacting ecosystems that provide a variety of habit patches
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Metapopulation
population divided into several populations among which individuals occasionally disperse
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Spatial distribution occurs because...
different habitats vary in suitability
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source habitats
areas where local reproductive success is greater than mortality
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source population effect
greater population densities, surplus individuals relocate
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sink habitat
local reproductive success is less than local mortality
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sink population effect
no immigration, extinction follows
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human population is growing rapidly because...
decrease in mortality rates, due to food production, medicine, and sanitation
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highly developed countries characteristics
longer life expectancies, lower birth rates, lower infant mortality rates
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moderately developed countries characteristics
medium life expectancies, medium birth rates, medium infant mortality rates
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less developed countries characteristics
high birth rates, high infant mortality rates, short life expectancies
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replacement-level fertility
number of children a couple must spawn to replace themselves
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replacement-level in highly developed countries
2.0
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replacement-level in developing countries
2.7
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total fertility rate
average number of children born to a woman during a lifetime (2.7 avg)
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doubling time
amount of time it would take for a country's population to double
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age structure
number and proportion of people at each age in a population
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age structure diagram
number of females and males at each age in a population
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population growth momentum
large number of 0 to 14 aged people who will become parents and are a larger group leading to more offspring
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relationships between environment and population growth
- rapidly growing population depletes resources
| - high desires exhausts resources quickly
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people overpopulation
when environment is worsening from too many people
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consumption overpopulation
when each individual consumes too large a share of resources
