Ecology and Population Biology Flashcards

Flashcards generated from lecture notes on Chapters 18 & 19, covering populations, communities, and ecosystems.

Ecology

The study of interactions of living organisms with each other and with their environment

Population

All members of a species that inhabit a specific geographical area at a specific time

Community

A collection of all the different species that inhabit a specific geographical area

Ecosystem

A community of organisms and the physical environment (air, water, nutrients, temperature)

Biosphere

Interactive collection of all of Earth’s ecosystems/ biomes

Biomes

Large areas characterized by a particular climate, vegetation, and animals

Population Density

Number of individuals per unit area

Quadrat

Small square plots where all individuals inside are counted, used for small, sessile organisms

Line Transect

A 50-100m line/rope is stretched out and all individuals within 1m distance are counted, used for larger, sessile organisms

Pitfall Traps

Small open containers buried in the ground that catch small species

Mist Nets

Nets used to catch flying animals

Baited Traps

Traps used for terrestrial mammals

Birth Rate

Number of births divided by population size

Death Rate

Number of deaths divided by population size

Intrinsic Growth Rate (r)

Birth rate minus death rate

Life Tables

Shows number of individuals in a population grouped by various ages

Survivorship Curves

Graphs that depict likelihood of individuals making it to a certain age in population, generated from life table data

The population grows

What happens to a population if the intrinsic growth rate (r) is greater than 0?

The population is in equilibrium

What happens to a population when the intrinsic growth rate (r) is equal to 0?

The population shrinks

What happens to a population when the intrinsic growth rate (r) is less than 0?

Opportunistic (r-selected) Species

Species that live fast and cheap, grow huge populations during good times

Equilibrium (K-selected) Species

Species that live slow but expensive, invest in stable populations that can withstand environmental fluctuations

Arithmetic Growth (linear)

A constant increase per unit time

Exponential Growth (J-shaped)

An increase proportional to population size

Carrying Capacity (K)

The population size when growth rate stops (the maximum population size the environment can sustain)

Biotic Factors

Pathogens are an example of these factors affecting population size

Abiotic Factors

Affects all individuals in an area equally- effect not dependent on population density

Weather

Acute, local atmospheric conditions

Climate

More consistent regional weather patterns

Axial Tilt

Earth is tilted 23.5˚ on the orbital plane

Latitude

Surface temperatures generally become cooler moving away from equator N and S

Atmospheric Circulation

Insolation heats ground and creates convective air currents

Topography

Mountains, valleys, islands, peninsulas, etc.

Biome

A very large ecosystem characterized by a particular climate & vegetation

Tundra

Also known as the 'treeless plain', characterized by permafrost

Taiga/ Boreal Forests

Characterized by long, cold winters and short, cool summers with conifer forests

Temperate Grasslands

Found in mid-latitude inland areas that used to contain temperate forests

Tropical Rainforests

Found near the equator with a hot & wet climate year-round and dense, permanent evergreen forests

Aquatic Biomes

Vary based on depth & distance from land, light availability and nutrient availability are major factors

Community

The collection of all species within a specified area

Ecological Dominants

The few species that dominate many communities numerically

Keystone Species

Species are not numerous but very important and maintain community structure

Species Richness

The number of different species making up a community

Species Evenness

The relative abundance of each species in the community

Competition

Interaction where both species are negatively affected

Predation and Parasitism

Interaction where one species benefits and the other is negatively affected

Mutualism

Interaction where both species benefits

Commensalism

Interaction where one species benefits and the other is unaffected

Amensalism

Interaction where one species is unaffected and the other is negatively affected

Neutralism

Interaction where both species are unaffected

Predation

Predator feeds on another organism’s tissues, killing it in the process

Parasitism

One species feeds on another’s living tissue and harms it in the process

Mutualism - Endosymbiont

Both species benefit and one organism lives entirely within the other

Commensalism

One organism benefits with no effect to other

Amensalism

One organism impedes or restricts the success of another without affecting itself

Trophic Levels

Feeding relationships in a community

Consumers (Heterotrophs)

Get their energy by consuming primary producers

Herbivores

Consume plants & algae

Carnivores

Consume animal tissues

Omnivores

Consume plants & animals

Detritivores

Consume detritus- remains of dead organisms or wastes from living organisms

Decomposers

Special detritivore- breaks down dead matter into inorganic components, which are recycled through the ecosystem

Biomagnification

Toxins that become concentrated in higher trophic level organisms

Biogeochemical Cycles

Play a role in recycling elements - NCHOPS and water are critical to biology