Environmental Science 105 Test 1

ecology

the study of the distribution/abundance of organisms

environmentalism

placing value on human interactions with the environment

what percent of water is freshwater

2.5%

hydrologic cycle

naturally balanced cycle of water use

water issues represent greater environmental problems like:

climate change, biodiversity loss, human population growth, land-use change, problem-solution overlap

unique properties of water

cohesion, less dense as a solid than a liquid, excellent solvent, high heat capacity

cohesion

surface tension, forms due to hydrogen bonding

water density

expands when freezing, water gets denser when its colder to a degree, helps thermohaline circulation

thermohaline circulation

sea currents move based on density of water which is based on temperature. important for heat transfer

high heat capacity

absorbs lots of heat before getting hot and cooling down, important for extreme temp changes in environment

excellent solvent

water molecules stick to ions and other polar compounds

dissolved oxygen saturation

how much oxygen is dissolved in water relative to how warm the water is

movement of heat and light

required for photosynthesis, influences activity, heats aquatic systems → stratification in lakes

reflection

small fraction of visible light is reflected back to atmosphere

scattering

light hits the surface and is refracted in a body of water by suspended particles

absorption

transfer of heat from the sun

transmission

heat is spread throughout the body of water with distance

eutrophic zone (light penetration)

enough light for photosynthesis

aphonic zone (light penetration)

not enough light for photosynthesis

compensation depth (light penetration)

photosynthesis=respiration

light attention

describes absorption of light with depth

eutrophic

very productive, murky water

mesotrophic

somewhat productive, somewhat clear

oligotrophic

not productive, clear water

attenuation coefficient

how light is moved across water bodies, more eutrophic means more light attenuation

limnology

the study of structural and functional interrelationships of organisms of inland waters as they are affected by their dynamic relationships

watershed

the area of land where all of the water that falls on it and drains off of it goes to a common outlet

surface water

surface water collects in patterns related to topography and geology

dendritic

the most common form of drainage , develops in regions underlain by homogeneous material

stream order

a method of quantitatively assessing position along a continuum, maximum on Earth is 13

lake

slowly/nonflowing bodies of open water collected in a landscape depression, not connected to the ocean

tectonic lake

formed by movement in earths crust

glacial lake

formed by melted glaciers

earthslide lake

earth movement dams a stream

volcanic-caldera lake

volcano filled in with water

stratification

outcome of waters found in nature having different densities

epilimnion

uniformly warm, circulating water

thermocline

plane of rapid temperature change

hypolimnion

uniformly cold water

turn over

mixing of all layers of water, happens in the spring and fall

amictic

perennial ice cover, no wind mixing

monomictic

stratifies once per year (temperate)

dimictic

stratifies twice per year (temperate)

polymictic

frequent mixing — no predictable mixing pattern

meromictic

never mixes

factors affecting stratification

time of year, depth, shape, wind fetch, topography of adjacent land, inflow/outflow dynamics, solutes, seiche

autotroph

primary productivity

heterotroph

secondary productivity

primary production

conversion of inorganic energy into organic compounds by autotrophs

photoautotroph

uses sun to create energy

chemoautotroph

uses chemicals to create energy

secondary production

biomass of heterotrophs

leibigs law of the minimum

growth isn’t controlled by the total resources, but is limited by the scarcest resources

nutrients

any element required for the maintenance, development, and reproduction of organisms

redfield ratio

ratio of carbon to nitrogen to phosphorus 106:16:1

haber-bosch process

formation of ammonia from the hydrogen in fossil fuels and atmospheric nitrogen

where is most nitrogen

the atmosphere

where is most phosphorus

the soil and rock

why is phosphorus limited in lakes

phosphorus needs to come from an outside source of the lake and when it comes into the lake, it will settle and become buried rendering it unusable

eutrophication

process of becoming more eutrophic from an oligotrophic or mesotrophic class

cultural eutrophication

water pollution caused by excess plant nutrients speeds up natural eutrophication process

top down

a top predator controls community and ecosystem structure

bottom up

nutrient supply and productivity controls community and ecosystem structure

grenville orogeny

major mountain building event that created basement rock for all of north america

residual material

parent material derived from in situ weathering of bedrock with subsequent soil development in that material

transported material

parent materials that arise when previously weathered materials are transported away from their original site by agents such as water, wind, glaciers, or gravity

alluvial material

soil laid down in layers from flooding events

glacially transported materials

till vs outwash

glacial till

sediment pushed by glaciers, mixed up rocks

glacial outwash

can be sorted and rocky, from glacier

lacustrine soil

often clays, laid down seasonally, clay settles out in calm waters

aeolian soil

transported by wind, creates loess

vadose zone

unsaturated zone of ground

phreatic zone

saturated zone of ground

water table

line between saturated and unsaturated zones

porosity

total amount of open space in a material

permeability

interconnectedness of pores

aquifer

sediment/rock that has high porosity and permeability

aquatard

sediment/rock that has low porosity and permeability

topography of water table

mimics topography of surface, but depends on surface deposits of water

hydraulic head

potential energy available to groundwater

hydraulic gradient

difference in hydraulic head of distance

darcys law

measures rate of groundwater flow

groundwater residence time

how long water stays in an aquifer, can range from weeks to millennia

problems with over pumping

cone of depression, high density/overlapping, changes in an aquifers ability to hold water, well contamination, salt water intrusion