APES U2/3/9

Adaptation

A new trait that increases a organism’s fitness (ability to survive and reproduce)

Background extinction

The ongoing extinction of individual species due to environmental or ecological factors such as climate change, disease, loss of habitat, or competitive disadvantage.

Interspecific competition

Competition for resources amongst members of different species

• can cause species to become threetened, especially when combined with general habitat fragmentation or loss due to human land use

• can further threaten species already vulnerable to habitat disruption due to climate change

Intraspecific competition

Competition for resources amongst members of the same species

• competition like this provides a type of control on the population size (if the population grows but the amount of resources stays the same, the resources become limiting)

Selective pressure

Any external favor that changes the behavior and fitness of organisms within an environment

• ex. resource availability, abiotic environmental conditions, biological factors

• determine which genetic/behavioral traits are favorably adapted to the environment and which aren't

• will change in changing environments (traits that were once advantageous may not always be)

Biodiversity hotspot

An area that supports an especially great diversity of species, particularly species that are endemic to the area.

Biomagnification

Increasing concentration of toxic substances as they move up through different trophic levels in a food chain.

Buffer zone

A portion of a nature reserve surrounding a core natural area where land use controls are less stringent but still partially compatible with species’ resource requirements.

Climax community

A fairly stable, self-sustaining community in an advanced stage of ecological succession.

Colonization

When an organism or group of organisms starts a population in a habitat where the species was not already present.

Deforestation

Temporary or permanent removal of large expanses of forest for agriculture or settlements.

Ecological restoration

The process of reversing degradation and reestablishing aspects of an ecosystem that previously existed.

Ecological [range of =] tolerance

The range of conditions (such as temperature, salinity, pH, or sunlight) that an organism or species can endure before injury or death occurs.

• species and individual organisms both have a range for all the different environmental conditions of their habitat (each individual/species has a range of abiotic conditions it has adapted to)

• exists because of genetic biodiversity

• helps make population more resistant to disturbances

Ecosystem diversity

The variety of ecosystems on Earth, including deserts, grasslands, forests, mountains, oceans, lakes, rivers, and wetlands.

Ecotourism

Tourism to exotic or threatened ecosystems to observe wildlife or help preserve nature.

Edge effect

Changes in population or community structures that occur at the boundary of two or more habitats.

Endemic species

Species that are native to and found only within a limited area.

Foundation species

Species that play a major role in shaping a community by creating and enhancing a habitat that benefits other species.

Founder effect

Reduction in genomic variability that occurs when a small group of individuals becomes separated from a larger population.

Generalist species

A species with a broad ecological niche that can tolerate a wide range of conditions and use various resources.

• have an easier time adapting to environmental changes than specialist species

Genetic diversity

Variation of genes that exist within a species population.

• helps avoid inbreeding

• allows species to adapt to future environmental changes

• * measure of how different the genomes are of the individuals within a population of a given species

• exists because of random mutations, natural selection (—biotic and abiotic environmental stressors)

• more genetic diversity = more likely to have traits to handle environmental stressors

Genetic drift

A change in the genetic composition of a population over time as a result of random mating.

Global extinction

The widespread disappearance of a species.

Habitat corridors

Links of wildlife habitat that connect two or more larger areas of similar wildlife habitat, critical for ecological processes.

Habitat fragmentation

The reduction of a large, continuous area of habitat into smaller, isolated patches.

• occurs when large blocks of habitat are cut into smaller pieces by development such as roads or housing

  • remaining blocks of habitat may be too small to sustain populations of a number of species and the fragmentation often results in barriers to species movement

  • other ex. roads and pipelines, agricultural and urban land use, logging

• generalist feeders generally do well with habitat fragmentation, specialists do not

  • animals have to be able to adapt when this happens

• disrupts breeding, hunting, migration

Habitat island

Any island surrounded by a different habitat.

Indicator species

Species whose presence or absence serves as an early warning sign of environmental change or degradation.

Intrinsic/existence value

The value of an organism, species, ecosystem, or biodiversity based on its existence, regardless of usefulness.

Keystone species

A species whose impact on its community or ecosystem is disproportionately large compared to its abundance.

Local extinction

The disappearance of a species from part of its natural range.

Mass extinction

A catastrophic event in which major groups of species are wiped out over a short time.

MPAs (marine protected areas)

Areas of the marine environment reserved by laws to provide lasting protection for natural and cultural resources.

Multiple-use land

U.S. classification designating lands for recreation, grazing, timber harvesting, and mineral extraction.

National Forest

Federally-owned land where logging and grazing are permitted under managed conditions.

National Park

Reserves managed for scientific, educational, and recreational use, often for their beauty or unique landforms.

• natural habitats surrounded by human developed land

National Wildlife Refuge (NWR)

Federal public lands managed primarily for wildlife protection.

Old-growth forests

Uncut or regenerated forests that have not been seriously disturbed for several hundred years or more.

Overgrazing

Damage to grasses and roots caused by too many animals grazing for too long.

Pioneer species

The first species to populate an area during primary succession.

Poaching

Illegal hunting, capturing, or killing of wildlife, often for commercial purposes.

Population bottleneck (Bottleneck event)

A sharp reduction in population size due to environmental events or human activities.

• * an environmental disturbance that drastically reduces population size and kills organisms regardless of their genome

• surviving population is smaller and because individuals die randomly, it doesn’t represent genetic diversity of the original population

• reduces genetic diversity → therefore more venerable to future environmental disasters

Precautionary principle

Taking precautionary measures when an activity poses threats to the environment or human health, even if cause and effect are not fully established.

Primary succession

The process by which pioneer species colonize an uninhabitable area and generate nitrogen for other plant communities.

Range of tolerance

The limits to the abiotic conditions that a species can tolerate.

Reproductive isolation

Separation of species or populations so they cannot interbreed and produce fertile offspring.

Secondary succession

Type of ecological succession when a climax community or intermediate community is impacted by a disturbance… This restarts the cycle of succession, but not back to the beginning—soil and nutrients are still present

Species bio/diversity

The number and variety of species in the world or in a particular region.

• the number of different species in an ecosystem

• the balance or evenness of the population sizes of all species in the ecosystem

Ecosystem bio/diversity

The number of different habitats available in a given area.

Higher biodiversity =

= Higher ecosystem/population health

Species richness (r)

Total number of different species found in an ecosystem.

• high (r) is a good sign of ecosystem health as more species means more quality resources

Species evenness

Measure of how all of the individual organisms in an ecosystem are balanced between the different species.

Inbreeding depression

Reduced survival and fertility of offspring of related individuals.

Inbreeding

When organisms mate with closely related “family“ members.

• leads to inbreeding depression

• smaller populations are more likely to experience inbreeding due to trouble finding non-related male

Resilience

The ability of an ecosystem to return to its original conditions after a major disturbance (ex. wind storm, fire, flood, etc.)

• ecosystem suffers then bounces back

Higher species diversity =

= Higher ecosystem resilience

• higher species diversity means more plant species to repopulate disturbed ground, anchor soil, and provide food and habitat for animal species

What are the three levels of biodiversity?

Genetic, species, and ecosystem

Specialist species

Species with a narrow ecological niche. They may be able to (1) live in only one type of habitat, (2) tolerate only a narrow range of climatic and other environmental conditions, or (3) use only one type or a few types of food.

• have a harder time adapting to environmental changes than generalist species

What are some things that increase genetic biodiversity?

• Low variation in environmental conditions (but still some)

• Evolution

• Minor disturbances like surface fires, wind storms, floods, etc.

• High habitat diversity

What are some things that decrease genetic biodiversity?

• Continuous environmental stress

• Extinction

• Extreme disturbances like crown fires, clear cutting, hurricanes, etc.

• Geographic isolation

• Invasive species

Ecosystem services

Goods that come from natural resources or services/functions that ecosystems carry out that have measurable economic/financial value to humans.

• = $

What happens when human activities disrupt the ability of ecosystems to function?

The value of the ecosystem services it provides is decreased.

Provisioning (ecosystem service)

Goods taken directly from ecosystems or made from natural resources.

• ex. wood, paper, food, etc…

• products

Examples of disruptions to provisioning ecosystem service

• Overharvesting

• Overfishing

• Water pollution

• Clearing land for agriculture/urbanization

Regulating (ecosystem service)

Natural ecosystems regulate climate/air quality, reducing storm damage and healthcare costs.

• ex. trees store CO2 through photosynthesis which reduces rate of climate change and lessens damage caused by rising sea level and reduces crop failure from drought

• indirect uses

Examples of disruptions to regulating ecosystem service

• Deforestation

  • logging, clearing land for agriculture/urbanization, etc…

Supporting (ecosystem service)

Natural ecosystems support processes we do ourselves, making them cheaper and easier.

• ex. bees pollenate crops

• incorporates all ecosystem services

Examples of disruptions to supporting ecosystem service

• Pollinator habitat loss

• Filling in wetlands for development

  • decreases water filtration services and have to pay more money to filter water

Cultural (ecosystem service)

Money generated by recreation or scientific knowledge.

• recreation ex. parks, camping, tours, etc…

• ethical/indirect value

Examples of disruptions to cultural ecosystem service

• Deforestation

• Pollution

• Urbanization

Burning fossil fuel—impact on biodiversity

Acid deposition = pH of water and climate disruption

Deforestation—impact on biodiversity

Loss of species and habitat

Industrial agriculture—impact on biodiversity

Monocropping (growing a single crop species over a large area → can lead to quicker buildup and spread of pests and diseases in a susceptible crop)

Overfishing—impact on biodiversity

Loss of species

Pesticide use—impact on biodiversity

Loss of species

Genetically modified crops—impact on biodiversity

Loss of genetic variation

Water pollution—impact on biodiversity

Loss of aquatic habitat diversity

Island biodiversity

Study of ecological relationships and community structure on islands.

• islands can be actual islands in a body of water or figurative habitat islands such as central park in NYC or National Parks (natural habitats surrounded by human developed land)

• two basic “rules“ or observations:

  • larger islands support more total species

  • islands closer to the “mainland“ support more species

Larger islands lead to…

• Higher ecosystem diversity

  • greater ecosystem diversity = more food and habitat resources

• More available niches/roles

  • ex. all the different food sources available to birds on Galapagos

• Larger population sizes (more genetically diverse and more resistant to environmental disturbance)

• Lower extinction rate (species less likely to die off)

Correlation between island size and species richness

Positive

Being closer to the mainland leads to…

Higher species richness.

• Easier for more species to migrate to island from mainland (swim/fly)

• More continual migration of individuals to the island habitat which brings more genetic diversity and larger population size

What kind of relationship is there between island distance from mainland and species richness?

Inverse

• the further away from mainland, the fewer species

Adaptive radiation

Single species rapidly evolving into several new species to use different resources and reduce competition.

• ex. Galapagos Finches → different beaks quickly evolve to fit variety of different food sources on island

• single colonizing species from mainland quickly evolves to many slightly different species to adapt to new island condition

Core habitat

Located centrally within a patch, surrounded by the same type of habitat.

Edge habitat

Borders a different habitat type.

• aka boundary habitat

• joint habitat/where they meet has different characteristics than the middle of the individual ones

• some species thrive and have greater biodiversity here because of food diversity, nutrient resources, and shelter

  • organisms have access to both ecosystem and resources within both

• can expand the range of potentially disruptive species

  • ex. brown headed cowbird → brood parasite that leaves its eggs in the nests of songbirds for them to unknowingly raise (egg hatches and gets big and takes over nest/area)

Habitat/Wildlife corridors

A link of wildlife habitat, generally native vegetation, which joins two or more larger areas of similar wildlife habitat.

• critical for the maintenance of ecological processes including allowing for the movement of animals and the continuation of viable populations

Limiting factor

The one most likely to regulate population growth.

Optimal/Optimum range

Range where organisms survive, grow, and reproduce.

Zone of physiological stress

Range where organisms survive, but experience some stress/reduced fitness (such as infertility, lack of growth, decreased activity, etc…).

• make sure to list specific reduced fitness/physiological stress examples when writing about this for an FRQ

Zone of intolerance

Range where the organism will die (ex. thermal shock, suffocation, lack of food/water/oxygen).

• make sure to list specific reduced fitness/physiological stress examples when writing about this for an FRQ

Natural disturbance

A natural event that disrupts the structure and/or function of an ecosystem.

• can be greater than human disruptions

• can appear on three different timescales: periodic, episodic, or random

Periodic disturbance

Natural disturbance that occurs with regular frequency.

• ex. dry-wet seasons (like in a savanna)

Episodic disturbance

Occasional natural disturbances with irregular frequency.

• ex. hurricanes, droughts, fires

Random disturbance

Natural disturbance with no regular frequency.

• ex. volcanoes, earthquakes, asteroids

Earth’s climate has varied over time because of… (one ex.)

Slight changes in earth’s orbit and tilt cause mini ice ages and warmer periods.

Why has sea level varied over time? (one/main ex.)

Glacial ice on earth melting and forming.

• increased CO2 → warmer temps → glacial ice melts → sea level rises

Major environmental disturbances result in…

Widespread habitat changes or losses.

• IMPORTANT EX. → rising sea level floods coastal and estuary (bodies of water where river meets sea) habitats

Anthropogenic

Caused or produced by humans.

Migration

Seasonal movement of animals, often involving moving from one habitat to another.

• adaptive response, usually because of seasonal or geographic changes in resources/mating opportunities

• can occur as a result of natural disruptions

  • ex. ocean species moving further north as water temperature increases

  • ex. wildebeests migrating to follow rain patterns of African savanna

Trophic cascade (U1)

An ecological phenomenon triggered by the addition or removal of top predators and involving reciprocal changes in the relative populations of predator and prey through a food chain, which often results in dramatic changes in ecosystem structure and nutrient cycling.

• adding or removing top predators changes how the food cycle/pyramid works, resulting in changes in the ecosystem structure and nutrient cycling

Crossing over (genetics)

Creates new combos of genes (and therefore new traits).