APES Midterm Review

Symbiosis

relationship in which two species live closely together

Commensalism

one organism benefits and the other is unaffected

Parasitism

One organism benefits and the other is harmed

mutualism

both organisms benefit

Predation

the preying of one animal on others.

competition

the struggle between organisms to survive in a habitat with limited resources

resource partitioning

When species divide a niche to avoid competition for resources

invasive species

species that enter new ecosystems and multiply, harming native species and their habitats

Habitat/Biome

habitat is a place where a group of one organism lives / biome is a collection of habitats in a given region or climate

tropical rainforest

20-25 degrees C, in South America, middle Africa, SE Asia; 200-1000 cm of rain per year, home of sloths, jaguars, ocelot, rubber tree, orchid, cacao

temperate rainforest

4-12 degrees C, in Chile, Argentina, US, 60-200 cm of rain a year, home of red cedar, grand fir, bobcat, beaver, owl

Temperate deciduous forest

10 degrees C, 30-60 cm of rain a year, East US, Europe, East Asia, home of red cedar, moss, lichens, ferns, deer, raccoons, foxes

Taiga (Boreal Forest)

-54-21 degrees C, 40-100 degrees C, poor soil quality, home of pine, spruces, cedar, caribou, bear, wolf

Desert

-3-38 degrees C, 0-30 cm of rain, in Africa, Australia, Middle East, North America, home of succulents, acacia tree, camels, tortoise, and lizard

Savanna

20-30 degrees C, 75-100 cm of rain, in Africa, Australia, India, SE Asia, home of purple milkweed, elephant, zebra, lion, hare

Shrubland (Chaparral)

-30-30 degrees C, 75-150 cm of rain, in West US + North Africa, home of evergreen trees, fern, rabbit, jackal, antelope

Prairie (Temperate Grassland)

-5-20 degrees C, 50-90 cm of rain, in US, Western Asia, South America, home of buffalo grass, cacti, lions, wolves deer, prairie dogs, snakes

Tundra

-40-18 degrees C, 15-25 cm of rain, in North America, Russia, home of short shrubs, birch trees, polar bear, Arctic fox, caribou

freshwater biomes

lakes, ponds, rivers, streams and wetlands

marine aquatic biomes

oceans, coral reefs, estuaries

climatograph (climate diagram)

a visual representation of a region's average monthly temperature and precipitation

hydrologic cycle

the movement of water through the biosphere

Photosynthesis vs cellular respiration

Photosynthesis creates glucose, cellular respiration uses glucose for energy (ATP), photosynthesis releases oxygen, cell resp releases carbon dioxide

primary productivity

rate at which organic matter is created by producers in an ecosystem (depends on solar energy levels, carbon dioxide levels, and community interactions)

GPP (gross primary productivity)

The total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time

NPP (Net Primary Productivity)

The energy captured by producers in an ecosystem minus the energy producers respire

R (respiration)

amount of energy that producers respire

formula for NPP

NPP = GPP - R

The net primary productivity of a terrestrial ecososytem is found to be 9,000 kcal/m2 per year and the respiration of the producers is 16,000 kcal/m2 per year. What is the gross annual primary productivity for this ecosystem, in kcal/m2 per year?

9,000 + 16,000 = GPP = 25,000 kcal/m2 per year

food chain

primary eats autotrophs, secondary eats primary, tertiary eats secondary (less energy levels as consumption moves through the food chain)

Herbivores

Consumers that eat only plants

Carnivores

Consumers that eat only animals

Detritivores

Organisms that eat dead organic matter

Decomposers

Organisms that break down the dead remains of other organisms

Omnivores

Consumers that eat both plants and animals.

trophic level

step in a food chain or food web

trophic pyramid

Represents the distribution of biomass among trophic levels

10% rule of energy transfer

when energy is passed in an ecosystem from one trophic level to the next, only 10% of the energy will be passed on

If the primary producers of an ecosystem have approximately 34,000 kcal/m2/yr of energy in their biomass. How much energy is most likely available to tertiary consumers in this ecosystem?

34000/10/10 = 340 kcal/m2/yr

How is a food chain different than a food web?

a food chain outlines who eats whom / a food web is all of the food chains in an ecosystem

positive feedback loop

feedback loop that causes a system to change further in the same direction (release of methane in the Arctic accelerates the rate of global climate change)

negative feedback loop

A feedback loop that causes a system to change in the opposite direction from which it is moving (shivering in a cold environment helps heat the body up)

biodiversity

The number of different species in an area

genetic diversity

a measure of the genetic variation among individuals in a population

species diversity

Variety of different kinds of organisms that make up a community.

ecosystem diversity

variety of habitats, communities, and ecological processes in the biosphere

how does biodiversity influence how ecosystems respond to stressors?

greater biodiversity leads to higher stability (more different traits, more survival rates)

generalist species

species with a broad ecological niche (e.g. deer)

specialist species

species with a narrow ecological niche (e.g. panda bear)

species richness vs species evenness

richness: number of different species in an ecosystem

evenness: measure of abundance of all species in an ecosystem

ecosystem services

The process by which natural environments provide life-supporting resources

provisioning services

products obtained from ecosystems

regulating services

the service provided by natural systems that helps regulate environmental conditions

support services

Ecosystem services that are necessary for the production of all other ecosystem services

cultural services

ecosystems provide cultural or aesthetic benefits to many people

periodic disruptions

disruptions that occur in regular cycles

-wet/dry season

episodic disruputions

natural disruptions that occur occasionally at irregular intervals (El Nino, El Nina)

random disruptions

disruptions at no regular frequency (volcanoes, earthquakes, and asteroids)

intermediate disturbance hypothesis

moderate levels of disturbance can foster greater species diversity than low or high levels of disturbance.

succession

the process by which an ecosystem or community experiences change

primary succession

succession that occurs on surfaces where no soil exists

secondary succession

reestablishment of a damaged ecosystem in an area where the soil was left intact

indicator species

species that serve as early warnings that an ecosystem is being damaged

pioneer species

First species to populate an area during primary succession

keystone species

a species that has an unusually large effect on its ecosystem

climax communities

is often dominated by several large, long-lived tree species and the animals that live in and around it

intrinsic growth rates

(number of births) - (number of deaths)

population growth rate

(births-deaths/total population) x 100%

K-strategist species

Organisms characterized by few offspring, long life, lots of parental care. They fluctuate at or near the carrying capacity of their environment.

R-strategist species

Show exponential growth, mature quickly, tend to have short lives, do not care for young causing high juvenile mortality, have many offspring, not sensitive to environmental resistance.

biotic potential

The maximum rate at which a population could increase under ideal conditions

carrying capacity

The largest population that an area can support

overshoot

when a population becomes larger than the environment's carrying capacity

dieback

a sudden decline in population

type 1 species

K-selected species: high survivorship when young, rapid decline in survival at an old age

type 2 species

have an approximately equal probability of dying at any age

type 3 species

invest little energy raising their young; few individuals survive to reproduce

density independent factors

limiting factors whose influence is not affected by population density (temperature, floods, pollution)

density dependent factors

limiting factor that depends on population size (disease, predation, competition

exponential growth model

growth model that estimates a population's future size after a period of time based on the intrinsic growth rate and the number of reproducing individuals currently in the population

logistic growth model

describes a population whose growth is initially exponential, but slows as the population approaches the carrying capacity of the environment

population oscillations

some populations experience recurring cycles of overshoots and die-offs that lead to a pattern of oscillations around the carrying capacity of their environment

modern human population growth

regions that have the highest population growth would be in developing regions, lower would be in fully developed regions

CBR (Crude Birth Rate)

The number of live births per year per 1,000 people.

CDR (Crude Death Rate)

The total number of deaths in a year per 1000 people

doubling time (rule of 70)

70 divided by the percent growth rate

immigration

Moving into a population (going in)

emigration

Migration from a location (exiting)

demographic transition model

A sequence of demographic changes in which a country moves from high birth and death rates to low birth and death rates through time.

stage 1 of demographic transition

preindustrial society; birth and death rates are both high

stage 2 of demographic transition

High growth; Rapidly declining death rates and very high birth rates; Industrial societies or societies that benefit from the medical revolution.

stage 3 of demographic transition

Decreasing growth; Birth rates rapidly decline; death rates continue to decline; Highly urban societies.

stage 4 of demographic transition

Low growth; Very low birth and death rates = zero population growth

percent change

A ratio that compares the change in a quantity to the original amount (final - initial)/initial x100%

3 types of rocks

igneous, sedimentary, metamorphic

rock cycle

A series of processes on the surface and inside Earth that slowly changes rocks from one kind to another

metamorphic rock gets pressurized and melted, turned into igneous rock, which is eroded and weathered and changed into sedimentary rock

physical vs chemical weathering

Physical= Solid rock is fragmented by mechanical processes like freezing and thawing