Terms (chapter 1-18) Flashcards
Limnology
Study of inland waters: lakes, reservoirs, rivers, streams, wetlands and estuaries
Aphotic or Tropholytic Zone
The volume of water or the area of sediments where the photosynthetically available radiation (PAR) is < 1% of that entering the water and where plant respiration is larger than plant photosynthesis
–> little to no sunlight
Benthos
The community associated with the bottom– refers most community to the animal community
Catchment, drainage basin or watershed
The area of land that land drains towards on aquatic system
Ecosystem
The unit of organization in which all living organisms collectively interact with the physical/ chemical enviro as an integrated system
Epilimnion
The surface-mixed (turbulent) layer in those lakes that exhibit a vertical temp stratification, with the lower boundary in content with the metalimnion
Hypolimnion
The deep, cooler layer of a stratified lake lying below the metalimnion, characterized by a greatly reduced turbulence and usually insufficient light to allow algal growth
Lentic System
Standing water system (ponds, lakes) in which the flow is primarily imposed by wind and heat is not primarily unidirectional
Littoral Zone
The near-shore region of lakes and lowland rivers where the sediments lie within the photic zone and where the shallower water flora is frequently dominated physically by macrophytes
Lotic System
Primarily unidirectional flowing water systems imposed by gravity (e.g.. rivers and streams)
Macrophytes
Community of multicellular emergent and submerged large plants dominating the shallow portions of littoral zones, lakes, slow-flowing rivers and wetlands
Metalimnion
The transition layer of water, between the epilimnion and hypolimnion, in which the temp declines with increasing depth
Mixed Layer
The upper water layer recently mixed by wind or temp induced currents (e.g.. surface area). = Epilimnion stratified lakes
Pelagic, Lacustrine or Limnetic Zone
The open water region beyond the littoral zone
Photic, Euphotic or Trophogenic Zone
The volume of water in which algal photosynthesis is on a diurnal basis, greater than algal respiration (PAR is > 1% of that entering the water
Plankton
The microscopic and small macroscopic community of the open water adapted to suspension and subject to passive movements imposed by wind and current
(eg. phytoplankton –> plant plankton and bacterioplankton and zooplankton –> animal plankton
Profundal Zone
The deep region (hypolimnion) of stratifying lakes, but mostly used with reference to deep-water sediments and their biota
Wetlands
Transition zones between terrestrial and aquatic systems where the soil are waterlogged for at least part of the year or covered by shallow waters, and which are typically occupied by rooted aquatic vegetation
- -> land consisting of marshes or swamps
- -> saturated lands
Name 3 challenges about measuring water
- Scale
- Amount of detail
- How to interpret the info
Name 5 different processes
- Production and Respiration
- Species interaction
- Growth and Loss Rates
- Physiology
- Biochemistry
What is the hierarchy order of organisms (largest to smallest)
Ecosystems > Communities > Population > Cells > Organisms
Keystone Species
Species that exert a major import on the behaviour on the system as a whole
Eg) Daphnia, zebra mussels
What can be define with using distinct boundaries
Structure and Function
What year was the Secchi disc developed?
1865
When was limnology first studied?
1901
When were lakes recognized to be an open system?
1915
Spatial Scale
Linkages between organism size and related processes
Is water a liquid crystal or true liquid? Why?
Water is liquid crystal because of its weak covalent bonds
- Liquid crystal: a substance that flows like a liquid but has some degree of ordering in the arrangement of its molecules
What are 5 properties of water
- High surface tension
- Moderate Viscosity
- Excellent solvent
- Dense at lower temps
- Essential for life
Specific Heat Capacity
Is the amount of heat need to raise or lower the temp of 1g of a substance by 1 deg C
–> takes 4.187 J to heat 1g of water to 1 deg C
Why is water important?
Without water there would be no photosynthesis resulting in no life on earth
How much of the worlds total water is fresh? And how much of that is accessible for human usage?
2.6% and 0.3%
Where does the fresh water not used by humans go?
Glaciers, ice caps, ground water
What is the most limiting resource on earth?
Freshwater
Water Residence Time (WRT)
Is the amount of water in a reservoir divided by either the rate of addition of water to the reservoir or the rate of loss from it
Groundwater = Long WRT
Lakes = Medium
Wetlands/rivers = Short
What are the top 3 counties supplied with water per capita?
- New Zealand
- Canada
- Norway
What are 3 critical roles wetlands and lakes play in?
- Organic chemical degradation
- Storage
- Water Purification
Name 5 things nourishment is greatly effected by
- Deforestation
- Pollution of freshwater
- Dam construction
- Increase catchment nutrient release
- With-drawl for human/ agricultural use
What can and can’t saline water be use for?
Can = extraction of salts (eg. NaCl) Cant = Drink or use for irrigation
River Discharge
is the volume of water flowing through a river channel
–> discharge from a drainage basin depends on precipitation, evapotranspiration and storage factors
Subsurface Runoff
Water that infiltrates in the unsaturated zone, from rain, snow melt, or other sources and moves laterally throwers the streams
Groundwater
Water held underground in the soil or in pores and crevices in rocks
Aquifer
A body of permeable rock that can contain or transmit groundwater
Water table
The level below which the ground water is saturated with water
What does runoff carry?
Dissolved materials to streams
eg) plant nutrients, organic matter, pesticides and other contaminants
What are 4 things that clear cutting cause?
- Nutrient update diminish
- Transpiration markedly reduced
- UV radiation reduced
- Growth inhibiting
What are 3 effects of clear cutting?
- Increase in stream discharge
- Increase in sediment erosion
- Accelerated loss of dissolved and particulate nutrient and organic matter
What are 3 advantages of forest vegetation?
- Stabilizes soil
- Reduces erosion
- Provides high transpiration that reduces runoff
Proglacial Lakes
Small lakes formed by ice barriers when glaciers retreated and blocked natural outflows
Kettle or Pothole Lakes
When drift covered charge blocks of ice that had been broken off the glacier, once melted formed relatively deep small lakes
Ice-Scour Lakes
Most abundant of all the glacial lakes, produced by retreating glacier scaring and gouging the jointed and fractured bedrock, creating a vast number of shallow basins now occupied by lakes, ponds and wetlands
Erosion Lakes
Glaciers scoured deep, often large basins where advancing ice sheets moved through existing valleys with relatively soft or highly fractured rocks
Tectonic Lakes
The forces that bring about warping of the earths surface, resulting in contain formation or lowering of an area
- -> most common in areas with low rain fall
- -> continues to deep and widen
Coastal Lakes
They are recent lakes because sea level only stabilized 6,000 years ago, after glacial melting ended. They are usually formed when a spit or bar builds up between headlands of marine and vert large freshwater bays
–> most remain slightly salted
Riverine Lakes
Wide variety of riverine lakes and this lake type dominates low latitude
–> most common are formed in floodplains and river deltas
Volcanic Lakes
Located in creators formed after an eruption and those resulting for flowing lava damming river allies
Solution of Karst Lakes
Are typically small, lying in basins of highly soluble rock (mostly limestone)
–> caves are also formed during similar processes
3 kinds of volcanic lakes
- formed after directly ejected through volcanic cone of underlying materials
- Those (often small and deep) produced following underground explosions brought about by hot lave (magma) coming on contact with groundwater or by degassing of magma
- Much larger craters resulting from collapse of the earths surface overlying an area (magma)
Limestone
is a rock soluble union contact with slightly acidic waters, created when CO2 released with water from precipitation yielding carbonic acid
Morphometry
Process of measuring the external shape and dimensions of landforms, living organisms or other objects
Bathymetric Map
Standard way of recording the morphometry of lakes
Fetch
Distance over which wind can blow and bring about turbulence
Stratify
Form layers
What 2 things help determine if a lake will stratify?
- Surface Area
2. Max Depth
What 3 things increase with increasing surface area?
- Number or plants
- Number of fish
- Number of invertebrate species
What are 3 effects of relatively deep lakes?
- Small fraction of likes surface area
- Decrease in light (and O2)
- Unproductive
What are 2 effects of transparent lakes?
- Disproportionally large surface area
2. Increase in growth and productivity
What does nutrient loading do with increasing means depth?
Decrease
–> in both saline and freshwater lakes
What are 5 things the underwater slope effects?
- Steepness and extend of the lateral zone
- Sediment stability and structure
- Sediment accumulation
- Angle by which waves and current impact the lake bottom
What are 4 things slope has an effect on?
- How well aquatic plants are rooted
- Stability of littoral zone
- Suitable habitat for fish feeding
- Abundance and distribution of benthic invertebrates
P normally has the lowest supply:demand ratio in what temperate zone?
- P is limiting nutrient
Oligotrophic (nutrient poor)
What is considered the primary limiting nutrient for phytoplankton?
Phosphorus (P)
N has the lowest supply:demand ratio in what temperate zone?
- N is limiting nutrient
Eutrophic (nutrient rich)
What increases biomass?
Nutrients (P and N)
River Continuum Concept (RCC)
- 1st conceptual framework for viewing lotic
- Links stream size, OM, and structuring in invertebrate communities within the channel from headwater to mouth
- Illustrates stream order
Allochthonous
Outside the aquatic system
What was considered to be the main source of energy in undisturbed, low order streams and covered by shaded trees?
Organic matter
Stream Order
Is a measure of the relative size of streams
!st Stream Order
Small, branched, upper tributaries of a permanently flowing river system
2nd Streams Order
Streams receiving 2 or more 1st order streams
Name 5 things that greatly affect lotic systems
- Forestry
- Agriculture
- Development
- Construction
- Fires
What are 3 things that are effected by forest fires/ cutting open up canopies?
- Reduced input of allochthonous OM
- Increase in temp
- Increase in primary production
Increase in open agricultural leads to…
Decrease in habitat index rate
Increase stream gradient (slope) leads to…
- Increase discharge rates
- Decrease depth
What are 3 things well-vegetated buffer zones reduce?
- Reduce stream bank erosion
- Reduce trap soil particles and absorbed nutrients on land
- Reduce heat reaching the water
Ecotones
A region of transition between 2 biological communities
Riparian Zone
Is the interface between land and a river or stream
Hyporheic Zone
Saturated interstitial areas beneath the stream bed and into the banks that contain some channel water
Floodplain
An area of low-lying ground adjacent to a river formed mainly of river sediments and subject to flooding
What is the most important nutrient source to rivers and lakes near urban areas?
Sewage wastewater
What is a major source of nutrient loading in small catchment areas?
Atmospheric loading
Terrestrial Catchment
All nutrients that nourish inland waters
Aerial Catchment
Nutrients that enter the aquatic system through deposition of drywall and wet fall
Good and bad qualities of increase catchment size
Good = Larger area to catch water and drain Bad = Larger distance for nutrients to be processed
What are a major source of methane and CO2 for the atmosphere?
Wetlands
Increase in water resistance leads to…
Decrease in dissolved organic carbon loading
Y - Axis
Dependent variable
X - Axis
Independent variable
When slope for drainage basin decreases this leads to…
Increase in area of catchment
Small Catchment
Steeper slope
Large catchment
Low slope
Drainage density decrease leads to…
Increase catchment
Tomography
Helps to determine stream morphology as we al the surface shape and size of lakes, their underwater form and depth and the abundance of wetlands
Water Residence Time (WRT)
The team the water has been in the system or its “age”
WRT is an ideal surrogate for what 4 things?
- Supple to aquatic systems
- Time allows for particles to sediment in lakes rather than flushed out
- Indicator of productivity of aquatic systems
- Rough time measures
What does a small drainage ratio imply?
Implies a small area bale to collect precipitation and release nutrients
High transparency has….
- Low TP
- High grazer
- Low Chl
- High O2
Low Transparency has…
- High TP
- Loz grazer
- High Chl
- Low O2
As WRT increase this leads to …
Decrease in dissolved organic carbon loading
What are 3 things solar radiation do?
- Drive photosynthesis
- Permits vision
- determines the amount of solar energy
What do wind energy and local heating determine?
If a lake will stratify and if so at what depth
UV range (in nm)
100-400nm
Infrared range (in nm)
700-3,000nm
PAR or visible light range (in nm)
400-700nm
Surface of water read amount of radiation is affected by what?
Latitude
Photometers
an instrument for measuring the intensity of light
As thickness increases this leads to…
Decrease in light transmittance
The fraction of PAR (photosynthetically active radiation) entering the water is determined by what? (3 things)
- Sunds angle
- Waves
- Ice or snow cover
Increase in shade lead to…
Decrease in incident radiation
Light absorption and reflection is low in what kind of ice?
Black ice because it cuts out any nutrients from entering the water
Red
Longer wavelengths (600-700nm)
Blue
Shorter wavelength (less than 400nm) - transmitted best in transparent waters
Fraction of cell volume packed with pigment decreases this leads to…
Increasing cell size
UV-C
(40-280nm)
Strongly absorbed by the atmosphere that negligible quantity reach the earth
Most dangerous
UV-B
(280-320nm)
Extremely injurious to organisms by damaging DNA and disrupting photosynthetic processes as well as pigment stability
UV-A
(320-400nm) Has been shown to cause minor photo damage and to reduce growth rates of algae, bacterial and protozoans - less energy per photon - Least dangerous - Better transmitted (less absorbed)
As US light decreases leads to…
Increase in depth
Kd
Vertical absorption coefficient
- Low Kd = higher heat content (transparency)
- High Kd = lower heat content (transparency)
Absorption rate decreases, when…
Depth increases
Secchi Disc
1st instrument used to provide a measure of water transparency
- can gather
Limitations of Secchi Disc (2 things)
Measurements can be affected by
- vision of the individual
- Roughness of water
Mictic
Mixing
With older temp waters ….
there will be more salt, making it more dense and decreasing its depth
Turnover
The time it takes to go from periods of stratification to periods of mixing
Temperate Lakes
(summer strat) separated by 2 periods of mixing at the temp of max density, when water temp is the same everywhere
Tropical Lakes
1 period each of strat and mixing, with the temp never declines below 3.94 deg C
Polar Lakes
Exhibiting as inverse temp strat, except for a period of summer mixing and having a water temp never higher than 3.94 deg C
Amitotic lakes are permanently covered by what?
Ice and its not mixed
Cold Monomictic Lakes
- covered with ice expect for summer
- no higher than 4 deg C
- wind turbulence
- unstratified
- single period of mixing
Cold Polymictic Lakes
- shallow
- wind exposure
- ice covered not in summer
Warm Polymictic Lakes
- shallow
- no ice ever
- small that storage capacity
- stratification happens daily
Dimictic Lakes
- ice covered part of the year
- stably strat
- 2 periods of the year for mixing (di)
- ice free days depend on temp
Warm Monomictic Lakes
- lack ice
- singel strat per year and mixing the rest of the time
Increase in transparency leads to
Increase in mixing depth
Where is max O2 found?
In the middle (metalimnion)
What 5 things help to determine the gradient?
- Fetch
- Solar radiation
- Shore line morphometry
- Wind protection
- Turbidity
What do climatic models predict?
- Warmer temps
2. Soil moisture
Temp increases, so does
Species richness
As P increases so does…
Chl
Why are dissolved inorganic carbon important for aquatic systems? (4 things)
- Buffers freshwater against rapid pH changes
- Determines amount available for photosynthesis
- Great bonding capacity for bicarbonate and carbonate
- Removes inorganic carbon
Most lakes are supersaturated with what?
CO2
Inorganic carbon depletion occur in…. (3 places)
- Productive lakes
- Limiting rates of phytoplankton
- Submerged macrophyte photosynthesis
pH
The alkalinity or acidity of water (acidic:1-14:basic)
What are most freshwater pH?
6-9
Low species richness is due to… (5 things)
- Acidified water
- High toxic levels of metals
- High temp
- High sulphur levels
- High levels of trace minerals
Intense fish predation leads to…
Increase in phytoplankton and CO2 removal
Removal od zooplankton fish leads to…
Increase in water clarity
Heterotrophic
Less photosynthesis and more respiration
Autotrophic
More photosynthesis and less respiration
Oxidation-Reduction Titration
Is the standard technique for determining Os levels in fresh water
Solubility is primarily determined by what?
Temperature
Increase in altitude does what to solubility ?
Increases too
Increase in salinity does what to solubility?
Decreases it
Volumetric Hypolimnetic O2 Depletion Rate
The rate at which hypolimnetic O2 is consumed in a given volume
- is a useful indication of nutrient loading and primary production rate
Increase in P leads to… (4 things)
- Increase in algae
- Decrease in light
- Increase in O2 depletion
- Decrease in photosynthesis
Positive Heterograde Profile
Lakes with max dissolved O2
Negative Heterograde Profile
Metalimnetic dissolved O2 min
Input of N and P lead too… (3 things)
- Algal blooms
- Algal toxins which are fatal to humans and fish
- Proliferations of waterborne pathogens
Increase in chlorination by products in drinking water (which is harmful to humans)
Land use that leads to climate change (6 things)
- Agriculture
- Farming
- Waste disposal
- Fertilizers
- Harvesting
- Hydrology
Aquatic systems are what kind of system?
Open
Internal Loading
The release of elements from sediments to the overlying water
Oxic
Contains O2
Anoxic
No O2
Increase in N deposition in remote lakes becomes, what?
P limited
