Ecological Concepts and Population Growth

These flashcards cover key concepts related to ecological scales, population characteristics, growth rates, and survivorship patterns, as outlined in the lecture notes.

What are the four ecological scales mentioned in the lecture?

Population, community, ecosystem, and biosphere.

What is a population?

A group of interbreeding organisms of one species occupying the same area at the same time.

Define a community in an ecological context.

Includes all populations (multiple species) residing in the same region.

What is an ecosystem composed of?

The biotic community plus the abiotic environment.

What does biosphere refer to?

All parts of the planet where life exists.

Define habitat.

The physical location where members of a population live.

What is population density?

The number of individuals of a species per unit area or unit volume of a habitat.

List the three types of population distributions.

Uniform, clumped, and random.

What methods can be used to estimate a population size?

Aerial photos, sampling small subsets, and mark-recapture.

What factors can separate populations into subpopulations?

Natural barriers like mountains or bodies of water.

What increases population size?

Births and migration into the population.

What is a survivorship curve?

A graph showing the proportion of surviving individuals at each age.

Describe a Type I survivorship curve.

Characterizes species that invest much energy caring for young with low early-life death rates.

What is the equation for calculating population growth?

G = rN, where G is the growth rate, r is the per capita growth rate, and N is the population size.

How does environmental resistance affect population growth?

It slows population growth as it combines factors that limit maximum growth rates.

Define carrying capacity.

The maximum number of individuals that an ecosystem can support indefinitely.

What is logistic growth?

Population growth that levels off as the population size approaches carrying capacity.

What distinguishes density-dependent factors?

Their effects increase as the population density rises.

What is an opportunistic life history?

Species that are short-lived, reproduce early, and produce many offspring with little care.

What factors play a role in demographic transition?

Shifts from high death rates and then high birth rates to low death rates and low birth rates.

Which regions have the highest and lowest population growth rates?

Africa has the highest rates; Europe and some developed nations in Asia have the lowest.

What characterizes a Type III survivorship curve?

Species that invest little energy in raising their young, leading to high death rates among offspring.

How is population density calculated?

Dividing the total population by the total land area.

What could limit the growth of a Bigfoot population according to the in-class question?

Factors like limited resources can reduce growth rates.

What does a logistic growth equation include?

G = rN(K-N)/K, where K is the carrying capacity.