ecology test 2

greenhouse effect

the process of solar radiation striking Earth, being converted to infrared radiation, and being absorbed and re-emitted by atmospheric gases

what are the most prevalent greenhouse gases?

H2O and CO2

is the greenhouse effect beneficial?

only when it's naturally occurring

what effect have humans had on the greenhouse effect?

we have increased the concentration of CO2, CH4 and N2O through fossil fuels, agriculture, and landfills + produced unnatural gases

albedo

the fraction of solar energy reflected by an object (low=absorbing more light, high=reflecting more light)

to what degree is the axis of the Earth tilted?

23.5 degrees

solar equator

the latitude receiving the most direct rays of the sun (not the same location all the time)

atmospheric convection currents

the circulation of air between the surface of Earth and the amosphere

saturation point

limit of the amount of water vapor that air can contain

adiabatic cooling

the cooling effect of reduced pressure on air as it rises higher and expands (results in rain)

adiabatic heating

the heating effect of increased pressure on air as it sinks down and decreases in volume

latent heat release

when water vapor is converted back to liquid, water releases energy in form of heat and warms air

the main deserts are all at what location on Earth?

30 degrees north and 30 degrees south

Hadley cells

the two circulation cells of air between the equator and 30 degrees north and 30 degrees south latitudes

intertropical convergence zone

the area where the two Hadley cells converge and cause large amounts of precipitation

what determines the location of the ITCZ?

the location of the solar equator

polar cells

atmospheric convection currents between 60 degree and 90 degree latitudes that are similar to Hadley cells

Coriolis effect

the deflection of an object's path due to the rotation of the Earth

northeast trade winds

winds that blow from the northeast to southwest

southeast trade winds

winds that blow from the southeast to northwest

westerlies

winds in mid-latitudes that move from west to east

what do ocean currents do?

distribute unequal heating of Earth's water and influence the location of different climates

which way does warm tropical water circulate?

away from the equator on eastern reaches

which way does cold polar water circulate?

towards the equator on western reaches

gyres

large-scale water circulation pattern between continents

upwelling

upward movement of water (cold water from ocean depths is drawn upward, typically happens on western coasts)

oceanic water circulation

cold water is forced equatorward from the poles along west coasts of major continents, results in coastal deserts

El Nino-Southern oscillation

trade winds reverse, moving warm water in the opposite direction

thermohaline circulation

a global pattern of surface and deep water currents that flow as a result of variations in temp and salinity that change the density of water

is there more precipitation in Northern or Southern hemisphere?

Southern hemisphere because there is more water in the Southern hemisphere and water generates precipitation

rain shadow

a region with dry conditions because mountains cause the winds to lose their moisture before reaching it

moist subtropical mid-latitude climate

warm dry summers and cold wet winters

moist continental mid-latitude

warm summer and cold winters with moderate precipitation

soil

laters of chemically and biologically altered material that overlies bedrock

what does soil contain?

mineral material from bedrock, organic matter from organisms, microorganisms, plants and animals

leaching

water movement through soil that can remove soluble minerals

what are the soil textures of sand, silt, and clay?

sand=large, silt=middle, clay=very fine

podsolization

acidic soils, nutrients from E horizon leach to B horizon, reduces fertility in B horizon (in cool moist climates and coniferous forests)

laterization

weathering to great depth, buildup of oxides, loss of sand and clay, low in mineral nutrients, reddish color due to oxidation (in warm, humid climates and tropical rainforests)

biomes

geographic regions that contain communities composed of organisms with similar adaptations, due to convergent evolution

convergent evolution

when two different species with unrelated ancestors have evolved similarly due to similar selective forces

Whittaker's concepts

1. boundaries between biomes aren't always clear. 2. biodiversity increases as temps and rainfall increase. 3. fire shapes vegetation toward drier end of spectrum within each temp range.

ecotone

region where two communities come together with a sharp boundary

Walter's scheme

climate + vegetation = biome name

climate diagrams

graphs that plot the average monthly temp and precipitation of a specific location on Earth

growing season

months that are warm enough to allow plant growth

tundra

coldest biome, low precipitation, treeless above permafrost, soil is acidic and nutrient poor, upper soils thaw during growing season, low species diversity

boreal forests

population by evergreen trees, short growing season and severe winters, rainfall is 50-100 mm, soil is acidic and podsolized, low species diversity

temperate rainforest

mild temps, high precipitation, evergreen trees, lower species diversity than tropical rainforest

temperate seasonal rainforest

moderate temps, moderate precipitation, deciduous trees, soils are slightly acidic and podsolized

woodlands/shrublands

hot dry summers and mild wet winters, drought-tolerant plants, 12 month growing season, frequent fires

temperate grasslands/cold deserts

hot dry summers and cold winters, grasses and flowering plants and drought-tolerant shrubs, soils are nutrient-rich

tropical rainforests

warm and rainy biome, plants constantly taking nutrients from soil, highest species diversity

tropical seasonal forests/savannas

warm temps and wet/dry seasons, deciduous trees, soil does not hold nutrients, high species diversity

subtropical deserts

hot temps, low rainfall, long growing season, soils have no organic matter and are neutral, low species diversity

lotic

flowing water

stream/creek

narrow channel of fast-flowing water

river

wide channel of slow-flowing water

are ecosystems more nutrient-rich and complex up- or downstream?

downstream

Riparian zone

terrestrial vegetation alongside rivers and streams

allochthonous

inputs of organic matter than come from outside of an ecosystem

autochthonous

inputs of organic matter that are produced by algae and aquatic plants inside an ecosystem

is most of the organic matter in streams allochthonous or autochthonous?

allochthonous

is most of the organic matter in rivers allochthonous or autochthonous?

autochthonous

turbidity

cloudiness of water created by stirring up sediment

why are dams built?

to control flooding, provide water for irrigation, and to generate electricity

how do dams affect the water?

water becomes warmer, stream bottoms become filled with silt, water released from dams has low oxygen, they alter seasonal cycles of flooding and disrupt animals

pond

aquatic biome smaller than a lake, non-flowing freshwater with some area of water that is too deep for plants to rise above the surface

lake

aquatic biome bigger than a pond, non-flowing freshwater with more area of water that is too deep for plants to rise above the surface

how are a lot of lakes and ponds created?

from glaciers or shifting basins

oxbow lakes

broad bends of what was once a river, cut off by shifts in the main channel

littoral zone

the shallow edge of a lake or pond containing rooted vegetation

limnetic zone

open water beyond the littoral zone, where the dominant photosynthetic organisms are algae

profundal zone

area in a lake that is too deep to receive sunlight

benthic zone

area with sediments at the bottom of the lake/pond

epilimnion

surface layer of water (most production occurs in the epilimnion)

hypolimnion

deeper layer of water (anaerobic conditions)

thermocline

middle of the epilimnion and hypolimnion, rapid changes in temp over short distance

freshwater wetland

aquatic biome with standing freshwater or saturated soils, shallow enough for emergent vegetation throughout all depths

swamps

contains emergent trees

marshes

contains emergent non-woody vegetation

bogs

contains acidic water and adapted vegetation

salt marshes

a saltwater biome that contains non-woody emergent vegetation

mangrove swamps

biome that occurs along tropical and subtropical coasts, and contains salt-tolerant trees with roots in water

intertidal zones

a biome consisting of the narrow band of coastline between high tide and low tide, temps and salt concentrations fluctuate with the tide

coral reefs

biome found in warm, shallow waters that are 20 degrees Celsius year-round

what is coral and why is it dying?

coral is a bunch of tiny animals in mutualistic relationship with algae that collect detritus and plankton. coral bleaching (when rising temps cause algal symbionts to leave) is causing corals to die.

neritic zone

ocean zone beyond the range of the lowest tidal level, high productivity

oceanic zone

ocean zone beyond neritic zone, nutrients are sparse and production is limited

photic zone

area of the neritic zone and oceaniz zones that contains enough light for algae photosynthesis

aphotic zone

area below photic zone where water is so deep that sunlight cannot penetrate, less productive but organisms are adapted

hydrothermal vents

water heats and re-emerges hot with minerals

life history

the schedule of an organism's life

what is a life history comprised of?

age of maturity, parity, allocation of energy to reproduction, fecundity, life span

thrushes vs. storm petrels

similar-sized birds but thrushes young age of maturity and short life span and storm petrels have later age of maturity and long life span

what influences life histories?

lifestyle of organisms and evolutionary responses

Lack's proposal

1. life history traits contribute to reproductive success and evolutionary fitness. 2. life histories vary in a consistent way with respect to factors in the environment.

what was the conclusion to Lack's experiment?

one could artificially increase the number of eggs per clutch to show that the number of offspring is limited by food supply

stress tolerators

plants with slow growth and late sexual maturity, use low amount of energy

competitors

plants with fast growth and early sexual maturity, use low amount of energy

ruderals

plants with fast growth and early sexual maturity, use high amount of energy, vegetative reproduction doesn't matter (they are weeds!!!)

K selection

long life, slow development, few offspring with high parental investment, low population growth

R selection

short life, quick development, lots of offspring with low parental investment, high population growth

principle of allocation

the observation that when resources are devoted to one aspect, there has to a tradeoff with another aspect

trade-off: offspring vs. size

less offspring=bigger offspring

trade-off: offspring number vs parental care

more offspring=less parental care

determinate growth

when an individual does not grow anymore once it initiates reproduction (organisms with long lifespan favor this)

indeterminate growth

when individual continues to grow after it initiates reproduction (organisms with short life span favor this)

what are the trade-offs for Trinidadian guppies?

in lower stream reaches, guppies face high predation and have short life spans but produce more offspring. in higher stream reaches, guppies face less predation and have longer life spans but produce less offspring.

senescence

decline in body condition leading to death

semelparity

when organisms reproduce only once in their life

iteroparity

when organisms reproduce multiple times during their life

annual

an organism with life span of 1 year

perennial

an organism with life span of more than 1 year

sexual reproduction

offspring inherit DNA from 2 parents

what are the 3 ingredients of evolution?

heritable traits, variation in traits, consequences of this variation in traits

reproductive success

passing on genes to the most amount of offspring as possible

what are costs to sexual reproduction?

mating behavior can attract predators, maintaining gonads costs more energy, evolutionary cost of meiosis (only passing half of your genes down rather than all of your genes like asexual reproduction)

asexual reproduction

offspring inherit DNA from single plant

vegetative reproduction

a form of asexual reproduction in which an individual is produced from the nonsexual tissues of a parent

clones

individuals that descended asexually from their parent and therefore have the exact same DNA

binary fission

reproduction through duplication of genes followed by division of cell into 2 identical ones

parthogenesis

a form of asexual reproduction in which an embryo is produced without fertilization

hermaphrodite

individual with both male and female gametes

what are benefits of sexual reproduction?

chance of losing bad mutations during meiosis, better coping with environmental variation, better chance of developing defenses against pathogens

sex ratio

ratio of male to female

promiscuity

as many matings as possible (most common)

polygamy

single member of one sex has many lasting pair bonds with other sex

monogamy

pair bond between one female and one male (can last for a mating season or for life)

sexual selection

selection by one sex for specific characteristics in individuals of the other sex

anthropomorphic bias

applying human terminology directly to animals and vice verse is dangerous because we are different