Exam 1 Flashcards
Water
- polar molecule (one side that is positively charged and one that is negative)
- H2O covalent bonds (share electrons); hydrogen bonds causes water molecules to associate in a cluster
- # of molecules per cluster decreases with increase in water temp
- dissolves other substances
- lattice like molecular configuration
Latent Heat of Vaporization
- heat doesn’t cause a change in temp but changes the phase or state; ie liquid to gas
- takes 540 cal/g/C to change a phase
- water is more stable and remarkably resistant to heating due to H+ bonds
Temperature Variation
- Terrestrial ecosystems 10-15 degrees C
- Aquatic ecosystems 1-2 degrees C
Specific Heat
- amount of heat required to raise the temp of 1 gram of water 1 degrees C
- water can hold a great deal of heat
Latent Heat of Fusion
- melting
- heat required to change ice to water with no change in temp.
- don’t need to break all H+ bonds, just some
- takes 80 cal/g/degrees C
Density
- water’s max density at 4 degrees C
- density of ice: 0.917 g cm^3
- density of water: 0.999 cm^3
- ice formation: angle expanded and lattice-like structure forms; ice less dense than water
- thermal expansion is the dominant force
Viscosity
- the state of being thick, sticky, and semifluid in consistency, due to internal friction
- honey has higher viscosity than water
Surface tension
- attraction of the particles in the surface layer by the bulk of the liquid, which tends to minimize surface area
- water has a high surface tension
Normal Conditions
- trade winds blow from east to west
- warm low pressure area around Australia & Asia
- causes upwellings near South America, heavy in nutrients, rich fishery in that area
El Nino
- weak or no trade winds
- warm moist air and water flows toward South America which causes lots of rain there and no upwellings
Lacustrine
relating to lakes
Paulustrine
relating to wetlands
Riverine
relating to rivers
Evapotranspiration
water evaporating from plants and trees out of their stomata
Watershed/ Basin
area surrounding a lake or river that all water drains into
Euphotic
light penetration; top layer
Aphotic
no light and no photosynthesis
Littoral zone
rooted and submerged plants; near shore area
Causes of circulation patterns in lakes
- wind (AKA fetch)
- Topography (hills, mtns can block wind)
- Amount of ions in the water
- Temperature (which relates to density)
- Depth
Lake ecosytems
- highly variable, heterogeneous (patchy) in physical, chemical and biological components
- temp, light, density, currents
- nutrients, ions, contaminants
- populations, growth rates: ie filter feeders at the outlet
Vertical migration
-organisms go toward the surface to feed at night when they are more invisible to predators
Dimictic
lake that has two turnovers per year
Monomictic
lake that has one turnover per year
Polymictic
multiple turnovers per year; usually shallow lakes; turnover by wind
Amicitc
no turnover ever; usually lakes in the Arctic
Meromictic
- sheltered, deep lakes that prevent a lot of wind
- accumulates ions that sink to the bottom
- lower layer never mixes (monolimnion)
- chemical content rains down on bottom
What influences light attenuation
- algae
- phytoplankton
- organic compounds (decaying leaves, tea color)
- soil particles, sedimentation
PAR
photosynthetically active radiation; sensors that measure light attenuation
Wavelengths and Energy
- longer wavelengths, less energy absorbed more quickly
- blue has highest energy and shortest wavelengths so it penetrates water the deepest
Albedo
light reflection
Cyanobacteria
- AKA microsystis releases a toxin microcystin
- liver toxin
- huge bloom in Lake Erie; city of Toledo; lots of agriculture and nutrient runoff
- increased moisture in spring and increased temps are two factors that lead to more cyanobacteria
Point Source
outlet, pipe; enters a body of water directly
Nonpoint Source
nondirect; ie. agricultural runoff; harder to stop nonpoint source since pollution source is harder to determine
Oxygen in water
- colder water holds more oxygen than warmer water
- 6-15 mg/L good, 4-6 stressed, 2-4 choking, 1-2 dying, 01 dead
Seiches
standing waves; bath tub effect; high water level at one end due to wind set-up (local rise in water level caused by wind)
Troph
nourishment, energy, productivity
Eutrophic
- high productivity; true
- photosynthesis restricted to epi
- high nutrient conc (phosphorus & nitrogen)
- hypo becomes anoxic
- secchi depth
Mesotrophic
intermediate productivity; middle
Oligotrophic
- low productivity; few
- clear water
- low nutrients
- low productivity
- secchi dept >3 m
- photic zone extended to hypo
- oxygen in hypo
- fish like salmoniods
N2
molecular nitrogen; found in atm, nonreactive nitrogen, triple bond, really hard to break apart (only can by nitrogen fixation)
NO2-
nitrite; toxic
NO3
nitrate; oxydized
NH4+
ammonium
Phosphorus
- sedimentary cycle; originally from weathering of rocks
- increased phosphorus=increased blooms
- also comes from agriculture, lawn fertilizer, runoff, sewage
PO4 3-
inorganic; phosphate
DOP
dissolved organic phosphate
PP
particulate phosphorus
Spring mixes
- heavy water going down; getting recirculation
- ice off, total lake mixing, bottom goes from anoxic to oxic and the phosphate can circulate in entire lake which can cause algal blooms
Nutrient loading
more algal production and more zooplankton
Daphnia
- water flies
- in the order cladocera
- feed on small types of algae and diatoms
- diatoms can’t fix nitrogen but cyanobacteria can
- Daphnia can’t feed on cyanobacteria
Chlorophyll a
- we can measure biomass of cyanobacteria/ phtoplankton by measuring chl-a
- a photosynthetic pigment
