Population Ecology Flashcards
What does ecology mean?
The study of the interrelationships between organisms and their enviornment.
Who is the Father of Ecology, meteorology, geography, and biogeography?
Alexander von Humboldt (1769-1859)
What is ecology concerned with?
The scientific definition of ecology, mathematical ecology, and biogeography.
What is the order of how living things are organized?
Biosphere to ecosystems to communities to populations to organisms to organ systems to organs to tissues to cells to molecules to atoms.
Can ecology be studied from a number of different perspectives?
Yes
What is a population?
A group of individuals in the same area at the same time that are all members of the same species.
Do populations exist alone?
No
What is a community?
A grouping of populations of different species interacting with one another in the same enviornment.
Most population ecologists study what?
Communities
Can a community just be a tree?
Yes
Do most ecologists study ecosystems?
Yes
What is the definition of an ecosystem?
An ecosystem is a very large naturally occurring community of living species occupying a major habitat and associated nonliving aspects.
What is the largest entity ecologists study?
The biosphere, or Earth
Healthy ecosystems include what to sustain the ecosystem?
Plants, fungi, animals, bacteria, protists, viruses, minerals, water, sunlight, and etc
What are the two other names for the biosphere?
Ecosphere or Earth
What are the four sorts of data must we collect for population ecology?
Size, density, distribution, and ages of individuals
Is Earth’s human population well sustainable?
Yes
What does size mean?
Number of individuals that belong to the same species and live in the same geographical area at the same time.
What does density mean?
The number of individuals per unit area or volume.
What does distribution mean?
The pattern of distribution of the individuals within the population.
What are the two things distribution is affected by?
Physical resources and behavioral adaptations of the organisms.
What is uniform distribution?
Occurs often where individuals must compete for a limiting resource
What is the least common distribution pattern?
Uniform distribution
What is clumped distribution?
When prime living conditions are not found uniformly throughout a habitat
What is the most common distribution pattern?
Clumped distribution
What is random distribution?
When prime living conditions are found throughout the habitat.
What is age structure?
The relative proportion of individuals of each age.
A growing population has what?
Higher proportion at lower end
A shrinking population has what?
Higher proportion at upper end
The red-cockaded woodpeckers at
The Nature Conservancy’s Piney Grove Reserve has what population?
A growing population
If rate of growth remains constant, the speed of the population growth will get what?
Faster and faster
What is environmental resistance?
Any environmental force that prevents a population from growing at its maximum potential.
Environmental resistances include what?
“Push-back” against population growth
Limiting factors
Will slow population growth until it stops, and may decline
Limited resources such as starvation, disease
What are the two types of environmental resistance?
Density dependent and density independent
What is a limiting factor?
Environmental aspects that determine where an organism lives.
Any environmental factor that is sufficiently in short supply becomes what?
The prime environmental resistance to population growth.
Density-dependent environmental resistance is what?
When an environmental resistance only provides resistance when the population sufficiently large.
What are examples of density dependent controls?
Disease, predation, housing/habitat shortages, starvation (famine)
Leads to lower reproductive rates
Self-regulating for most species
Game hunters are crucial when what is low and what is it part of?
Predation and density dependent resistance
Density independent environmental resistance includes what?
When population size does not matter and they are not usually useful regulators of population growth
What are examples of density independent environmental resistances?
Fire, hurricanes, tsunamis, floods, drought, volcanoes, natural disasters
