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Lakes
Aquatic Ecosystems
Term | Definition |
---|---|
Limnology | study of physical, chemical, and biological conditions of fresh water |
PAR | photosynthetically active radiation |
Metalimnion | zone in which temperature changes rapidly |
Holomictic | lake mixes from top to bottom during annual mixing cycle |
Dimictic | spring/fall turnover, mixes twice |
Monomictic | turn over only in summer |
Polymictic | mix every few days, year round |
Amictic | no turn over, ice covered |
Meromictic | deep or chemically stratified lakes that only mix partially due to lack of energy to overcome stratification |
TDS | total dissolved solids |
pH | potential hydrogen |
pH | measure of H+ ions on a solution |
Alkalinity | ability to resist change in pH |
Buffering Capacity | the capacity of a water body to accept H+ ions |
High Buffering Capacity | ability to accept H+ ions without a change in pH |
Low Buffering Capacity | inability to accept H+ ions without change in pH |
DOC | dissolved organic carbon |
DOC | organic compounds that pass through a mesh size of 0.45mm |
Turnover | important to replacement of O2 in hypolimnion, since thermal restricts distribution of O2 (summer and winter) |
Trophic Levels | all organisms in an ecosystem can be placed in trophic levels depending on what energy source they rely on and how they provide energy for other organisms in the food web |
Edaphic | nutrients available to water from weathering soils |
Lake Morphometry | volume, surface area, mean depth |
Retention Time | the time required to replace entire lake volume. time taken from entry to exit for every single molecule |
To determine trophic status of a lake | physical and chemical parameters can be used |
Photosynthesis | uses light as its source for energy |
Chemosynthesis | uses reduction of chemical compounds as its source of energy |
Primary Producers | autotrophs - from the base of the food chain |
Phosphorus | relatively unavailable. sources: run off, precipitation, groundwater |
Loading Rate | influenced by: land use, human activities, morphology. high loading rate, high productivity. for plant growth - algae blooms |
Phosphorus exists in two forms: | soluble reactive phosphorus (srp), particulate P SRP cycles P settles |
Nitrogen | used by plants to produce proteins. fixed by blue-green algae |
Current issues in Ontario Lakes | -habitat loss. -phosphorus loading. -long-term monitoring |