Freshwater Ecology Quiz #1

Chapters 1-7

Define: Continental water systems

Water bodies contained within continents, as opposed to oceanic systems which separate continents

What are some ways in which continental water systems can be formed

Topographic depressions, runoff and run-in, rain, volcanic eruptions leaving craters, etc.

Define: Limnology

The study of continental waters

Why do volcanic crater lakes have acidic conditions?

Due to the deposition of volcanic gases

What did Dr. Evelyn Hutchison do for modern day limnology?

Wrote A Tretise on Limnology, a comprehensive guide to studying inland waters

What are the three major compartments of water in the hydrologic cycle?

Oceanic, atmospheric, and land systems

Define: Fluxes

The movement of water along different compartments

The global renewable supply of water is about , ___ humans use __ of accessible runoff

39 000 km^3 / year, 54%

What is the largest freshwater aquifer in NA?

The Ogallala aquifer

What sector uses the most water in Canada?

Industrial (91.7%), specifically electric power (70% of that)

How much water does Canada use per year (in cubic M)

36.1 billion cubic m

What are the two groups of properties that make water what it is?

• Physical: Dictates how water acts as a solvent, and how density varies

• Chemical: Composition of the water molecule allows it to stay water in a wide range of temperatures. 

What kinds of bonds are present in water molecules?

Covalent bonds, hydrogen bonds

The maximum density of water occurs at __

4 degrees c

With increasing depth and pressure of water, ___ increases

Solubility

What are some of the properties of water?

High heat capacity, boiling and melting points, high surface tension, high heat of vapourisation, excellent solvent for ions and polar molecules

Define: Viscosity

Fluidity, resistance to change from one form to another

Define: Inertia

Resistance to a change in state of motion

What is the purpose of Reynold’s number?

Helps quantify spatial and velocity-related effects on viscosity and inertia, helps understand the effects of water and its movement on living organisms 

What is the formula for Reynold’s number?

Re = Fi / Fv (Fi = inertial force, Fv = viscous force)

Chemical diffusion is affected by:

Concentration gradients, advective transport, temperature, nature and size of molecules, interference by living organisms, etc. 

____ surface area leads to more diffusion

Higher

Diffusion of materials in water is described by ___ law

Fick’s law: Diffusion flux is +vely related to the diffusion coefficient, the concentration gradient, and the reciprocal distance between the source and location at which diffusion occurs 

Light transparency of water bodies can be measured by a ____

Secchi disk

Define: Hydrodynamics

Temporal and spatial movement and distribution of water in the environment

Define: Physiography

Physical geography

Define: Ecohydrology

Hydrology in relation to ecology

What are the two types of scale to consider when studying an organism?

Temporal and distance (Ex. how often does the organism reproduce, what is its lifespan, how big is it, how big is its habitat)

What is the difference between infiltration and percolation?

Infiltration occurs near the surface, percolation occurs underground

When the quantity of water exceeds the ____ (beyond soil saturation) water runs off

matric potential

Define: Sheet flow

Slow movement of rainwater or snowmelt over the landscape. Sheet flow can also happen underground

Define: Vandose / unsaturated layer

Mostly dry soil below surface. Thickness varies depending on water table, 0 — more than 100 m 

____ ____ determines the flow rate or water retention capacity

Sediment/rock porosity

Define: Hyporheic zone

The interacting zone between surface and groundwater

What is the most productive habitat on the planet?

Wetlands

What are some significant roles of wetlands?

• Maintenance of water quality

• Prevention of soil erosion

• Support species diversity

• Contribution to the fossil fuel and minerals

• Site of biogeochemical cycles

• Source of methane

• Moderation of climate change

What are some types of wetlands?

• Tidal salt marshes

• Tidal freshwater marshes

• Mangroves

• Freshwater marshes

• Deepwater swamp

• Riparian wetlands

What are the four main categories of wetland?

Coastal wetlands, fringe wetlands, depressional wetlands, and peatlands

What is the difference between a bog and a fen?

• Bog: Low productivity, acidic, ombrotrophic/precipitation fed, rich in sphagnum moss

• Fen: Minerotrophic/runoff fed, alkaline, richer, higher species diversity

Define: Basin, watershed, catchment area, drainage area

An area of land in which rain and runoff funnel into a shared body of water

What is the longest river?

The River Nile, at 6 758 km

What is a hydrograph?

A plot of discharge against time

What are the three types of stream?

Perennial (Always flowing)

Intermittent (Sometimes flowing, receives groundwater)
Ephemeral (flowing rarely, not receiving groundwater)

Define: Base flow

Flow from infiltration through subsurface sediments – a constant flow

What is a gaining vs losing stream?

Gaining streams increase in discharge as they move downstream

Loosing streams lose flow as they move downstream

What are the three parts of a river?

Riffle – shallow areas of streams having more frictional force on layers of water resulting in turbulent flow

Pools – deep areas with relatively slow water flow

Runs – rapidly moving water with smooth surface

What is a river reach?

Several runs, pools, and riffles

What is a river segment?

Several reaches, with varying distance between them

Define: Thalweg

Middle portion of the water (cross section) that moves with maximum velocity

Velocity of a river will be ____ at the outside of the curve and ____ at the inside.

Maximum, minimum

Outside edge of a river results in ____ while inside edge results in ____

Erosion, deposition

Who founded the Rosgen system of river classification?

Dave Rosgen, in the 80s-90s

What are the four levels of the Rosgen system?

1. Geomorphic characterization, based on valley shape & slope, assigned A-G

2. Morphological description, adds a number (1-6) based on field measurements such as river dimension

3. Stream condition, an assessment of a river’s health and stability

4. Validation, long-term monitoring to verify predictions

Define: Lentic

Non-flowing, opposite of logic

What is a Garben lake?

Lakes formed as a result of faults on the earth’s crust, allowing a block to slip down and form a depression

What forms a Horst lake?

Block tilt, leaving a depression filled with water

What is a block in hydrology?

A landmass which functions as a distinct hydrological and geological unit

What is another word for littoral?

Lacustrine

A ____ map gives contours of the bottom of a lake

Bathymetric

What is the epilimnion?

The upper part of stratified lakes

In temperate areas, mixing of water in lakes occurs in the ____ and ____

Spring, fall

What is a thermocline/metalimnion

The zone where a rapid fall in temperature occurs

What is the hypolimnion?

The lower part of the stratified layer, below the thermocline

Define: Dimictic

Lakes that mix two times per year, including typical temperate lakes