Chapter 14: Population ecology Flashcards
Population
A group of individuals of the same species in the same geographical region
Population ecologists
1) Changes in populations
2) Density
3) Age structure
4) Survivorship
1) Changes in populations
And their causes
2) Density
Number of individuals per unit of space
3) Age structure
How much of the population is young/old
Survivorship
Longevity/survival probabilities
Life tables
Data on how likely an individual is to survive to a future age
Mortality
Measure both odds of dying
Survivorship 1
Odd of surviving
Type 1
High probability of juvenile and adult survival; few offspring require large investment
Type 2
Intermediate probability of survival at any age; intermediate number and care of offspring
Type 3
Low probability of juvenile survival; many offspring with little/no parental investment
Survivorship varies depending on
Life history (How an organism survives and reproduces)
R-selected
Opportunistics
K-selected
Equilibrial
Population changes
Growth can be exponential (unlimited; J-shaped) or logistic (controlled; S-shaped; dependent upon carrying capacity)
Population change notes
Growth occurs if births > deaths; decline if deaths > birth
Regulation
Two factors control population sizes:
1) Density-dependent factors
2) Density-independent factors
Density-dependent factors
Stronger or weaker depending on population density
Density-independent factors
Unaffected by population density
Applications
Three management are included:
1) Conservation
2) Sustainability
3) Mimimizing invasive (non-native) & Pest species
Biological control
Importing natural predators/pathogens
Chemical control
Herbicides, insecticides, poisons and more
Integrated pest management
Use of multiple control forms, and cultural changes (reduction of monoculture and less emphasis on total pest elimination)
Note on Human Populations
Human population growth curve: logistics or exponential?
Ecological footprint
Estimate of how much land/water each individual or society requires to maintain their lifestyle
Globally, each person should get
2.1 global hectares
A decade ago, we each
USED 2.6
Use technology to maintain artificially.
Temporary fix and eliminate competition
