ecology exam 3 final

global temp is influenced by

global temp is influenced by

solar radiation, greenhouse gases, ocean currents, topography

keeling curve

graph that shows the ongoing changes in the concentration of CO2 in the atmosphere

keeling curve drivers (cause CO2 increases)

aerosols, ozone, solar, volcanoes

positive feedback mechanism

climate feedback in which some initial change in the climate causes a secondary change that amplifies the initial change (example: ice-albedo feedback)

ice-albedo feedback

melting of ice corresponds with decrease in albedo (sun melts ice, reveals low albedo ground that absorbs more heat)

albedo effect

ability of surfaces to reflect sunlight (low albedo, darker surfaces absorb heat and high albedo, lighter surfaces reflect heat)

NPP

net primary productivity, amount in carbon retained in an ecosystem (amount of plant material left over for consumption by detrivores and herbivores)

GPP

gross primary production, total amount fo carbon produced by photosynthesis of plants

sea level rise primary contributors

melting ice/glaciers, thermal expansion (heating of water)

food chain length limited by

energy transfer proficiency, nutrient content of levels below, base NPP in web

hockey stick graph

represents mean global temp, which has spiked (resulting in linear growth followed by sudden, rapid growth)

hockey stick graph driver

greenhouse gases (least affected by aerosols)

primary production

chemical energy generated by autotrophs during photosynthesis

GPP controlled by

climate, leaf area index

NEE

net ecosystem exchange, total amount of energy fixed by autotrophs, results in increase in living plant matter minus heterotrophic respiration

biome distribution

varies with climate

NPP varies with

biome distribution, plant size and age

NPP limited by

nitrogen levels

NPP consumption

more consumed in aquatic systems than terrestrial

trophic dynamics

determines how energy and nutrients move through an ecosystem, by determining what an organism eats and what eats them

energy consumption in the trophic pyramid

about 90% of energy consumed at one trophic level is lost as heat in the transfer to the next level (2nd rule thermodynamics)

terrestrial trophic pyramid

energy and biomass pyramids similar as they are closely related

marine trophic pyramid

biomass pyramid inverted from energy pyramid, as lifespan increases going up trophic levels

trophic efficiency components

consumption efficiency, assimilation efficiency, production efficiency (NPP n / NPP n-1)

assimilation efficiency

proportion of digested food assimilated

productive efficiency

proportion of assimilated food that goes into new consumer biomass

consumption efficiency

proportion of available energy ingested

bioaccumulation

when chemical aren't metabolized or excreted and become more concentrated in tissues over a lifetime

biomagnification

concentration increases in animals at higher trophic levels, as they consume prey with higher concentrations

nitrogen sources

plants, atmospheric inputs (fixation, deposition)

nitrogen cycle

plants absorb soluble N, heterotrophs consume plants and obtain N, decomposition releases N

mechanical weathering

physical breakdown through physical disturbance, freezing/thawing, plant roots

chemical weathering

chemical reactions release soluble forms of mineral elements

nitrogen resorption

breakdown of chlorophyll and re/uptake of N (in leaves, greater change in leaf colors [yellow], greater N resorption)

greenhouse effect

gases trapping heat in the atmosphere (CO2, NO, CH4, fluorinated gases)

how greenhouse gases control temperature

absorb and re-emit infrared radiation in all directions

Moore's law

computing power tends to double every 2 years

grain

size of smallest homogenous unit of study (ex. a pixel in a digital image); determines resolution

extent

boundary of the area or time period encompasses by the study (spatial or temporal)

ecosystem processing scale

shrub cover change - 3m pixels forest expansion - 10m pixels agricultural productivity - 250m pixels sea surface temperature - 1,000m pixels

(NOT AREA)

rain shadow effect

inward slope facing prevailing winds has high precipation and lush vegetation, while the leeward slopes suffers

topography effect on climate

when air masses meet mountains, they are forced up, cooling and releasing precipitation

uplift

air molecules expand and become less dense when warmers (rise), air molecules contract and become more dense when cold (falls)

(HOT AIR BALLOON)

energy balance patterns

as solar energy leaves sun, some is absorbed and some is reflected

upwelling

when deep ocean nutrients rise to surface

thermohaline circulation

circulation driven by temperature and salt

ocean currents affect

regional climate

subsidence

prevailing winds approaching dip in earths surface create high pressure zone (creates arid biome)

climate determinants

solar radiation intensity and distribution

high vs low pressure zones and precipitation

high pressure= low precipitation low pressure= high precipitation

ecological question requirements:

location, time, situation, possible solution

why is the earth warmer at the equator?

due to the curvature of earth, sun rays are most direct at the equator

nitrogen fixation

process of converting N2 to biologically useful form

how atmospheric circulation cells influence global precipitation patterns

as air is heated and cooled, it allows for a higher or lower water holding capacity. when warm air rises in the atmosphere, the temperature drops and releases moisture as precipitation. as cool, dry air falls to the surface, high pressure zones are created that give rise to arid biomes.