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Water Cycle

1. Atmosphere Storage: additions - evaporation/condensation off ocean, evapotranspiration off forests, sublimation off ice/snow, evaporation off/condensation off of freshwater storage

2. Groundwater Storage: additions - infiltration from precipitation

3. Freshwater Storage: additions - Groundwater discharge forming springs and adding to lakes/streams, surface runoff, snowmelt runoff, stream flow

4. Ocean Storage: additions: surface runoff

5. Ice and snow storage: snow precipitate

Rainfall dominated hydrograph

Discharge dominates Fall, Winter, and Spring. Low discharge during Summer months

Snowmelt Dominated hydrograph

Discharge highest during Spring months. Winter, summer, fall all have very low discharge rates due to storage as snow/ice

Mixed glacier-melt and snowmelt hydrograph

Lowest discharge only in height of winter in which precipitate dominates as snow and too cold for melt to occur. Highest discharge during spring - summer

Where in BC are the highest patterns of mean annual peak flows? The lowest?

Highest \= Coast/Caribou
Lowest \= Interior plateau

Values of Water

1. Direct human consumption

2. Aquatic Life for salmonids, fishes, etc.

3. Hydrological Features

4. Agriculture for crops and livestock

5. Industry

6. Hydropower

7. Recreation

8. Amenity

Freshwater Ecosystem Services

1. Provisioning (water supply/fish)

2. Regulation (water purification, waste management, flood control)

3. Supporting (nutrient cycling, primary production)

4. Cultural (recreation)

Fluvial Geomorphology

The morphology of stream networks or, physical arrangements of each piece and the study of the processes by which such arrangements are created

Watershed

Divide between catchments

Contributing Area

Area generating flow to the channel

3 terms: catchment, watershed, basin/drainage basin
Catchment preferred!

Catchment components

Hillslope/upslope
Flood plain between one hillslope to next
Terraces \= forest patches of varying ages within floodplain

Channel

Path by which water and sediments flow through.

Active channel

Re-arranged on at least an annual basis

Wetted channel

Water in channel at time of observation

Bankfull channel

Margin where active channel gives way to the true channel margin or bank

Floodplain

Area that receives excess water from occasional overtopping of banks

Terraces

built up, former floodplains that are now vegetated and above floodplain level

Hillslope

part of contributing area beyond floodplain

Catchments variation in size

1. Stream System - main stream + tributaries

2. Segment System - one stream looked at in isolation

3. Reach System - one portion of stream

4. Pool/riffle System - one specific curve or area of reach

5. Microhabitat System - leaf/stick detritus in margin, sand-silt over cobbles, moss on boulder, etc.

Streams

All flowing waters - brooks, becks, branch, creeks, streams, rivers

Challenges of stream ordering

1. Dependent on map scale

2. Dependent on landscape

3. Small streams can be easily missed due to canopy closure despite being permanently flowing

River Continuum Concept

All streams consist of gradual transitions, thus not easy to capture each stream by strict classification. This is because the properties of streams depend on what goes on upstream.

Increases in stream size related to?

1. Increased stream flow

2. Decreased channel gradient

3. Increased amount of stored sediment

4. Decreased grain size

Tractive force

process that leads to formation of the morphology (geomorphology) of stream channels

Hydraulic radius

ratio of cross sectional area to wetted perimeter (if you had the surface and u think about how deep and wide it is)

Why are we concerned about peak flows in forest hydrology?

Because all forces act on stream channel at high flows, otherwise forces are hard to imagine. --\> ex. tractive force may otherwise be written as
Tg \= depth * slope. With no flow, difficult to see tractive force impacts on stream

Transport Limited to Supply Limited Stream Bed Reach type hierarchy

Colluvial: Transport Limited

Alluvial:
braided --\> regime --\> pool/riffle --\> plane-bed --\> step-pool --\> cascade

Bedrock: Supply Limited

Alluvial channel

In which there is high sediment transport and re-working. Energy of water at high flow rearranges the channel and its banks (thus, the re-working)

Often have meandering reaches

Colluvial streams

stream power not enough to move dominant pieces of rock - these pieces are in place from glacial tills or fall in from hillslope

Material sources to streams

1. mass wasting - slope failures on hillslides deliver rock, soil, wood. Natural. Rate may be accelerated by land-use activities

2. Channelized debris flow - upstream flow brings rocks and wood to downstream reaches. Natural. Rate may be accelerated in catchments with forest harvesting

How do the spatial scales of a contributing area differ?

Differ in Habitat complexity via:

• Different tree species

• variation in elevation above water

• different ages of terraces

• different sizes of forest patches

Changes in floodplain

area colonized by vegetation since last point at which area was eroded by channel. Areas furthest away from current channel but still within floodplain are the oldest

Channel Flow vs. Hyporheic Flows

Channel flow - flow within actual channel. above ground
Hyporheic flow - flow through region beneath and alongside streambed. Mixing with shallow groundwater and surface water.

Meander Reach

Series of regular sinuous curves, bends, loops in channel. Erode sediment from outer curve of each meander bed and deposit it on the inner curve further down stream. Water flows faster in these deeper eroded sections

Riffle Pool Reach

Very common. Provide lots of food resources in the calmer regions and at the bottom for fish. Reach with alternation in stream flow due to stream structure from areas of relatively shallow to deeper waters. Areas of active erosion. Eroded material is deposited in the riffle areas between them.

Step pool Reach

Occur in steeper landscapes. Retain lots of large rocks, but not enough stream flow to have power to remove these rocks. Colluvial (material not moved by force of water)
Not alot of erosion but just enough that only smaller mobile objects get removed. No trout or salmonids - smaller fishes and freshwater invertebrates hide in shelter of small pools from predators.

Cascade Reach

Supply limitation, nothing to move. Dominated by bed rock

Variations in Stream Reach Types?

Predominant bed material, typical slope, pool spacing, dominant roughness elements

Colluvial Stream Reach

Variable bed material, \>20% slope, variable channel widths, dominated by boulders and large wood

Bedrock Stream Reach

Bedrock bed material, variable slope, variable channel widths, roughness elements dominated by streambed and banks

Cascade Stream Reach

Bedrock bed material, 8-30% slope,

Step-pool Stream Reach

cobble/boulder bed material, 4-8% slope, 1-4 channel width, dominant roughness elements are bedforms, boulders, large wood, banks

Plane-bed Stream Reach

Gravel/cobble bed material, 1-4% slope, no channel width, dominated by boulders, cobbles, and banks

Pool-riffle Stream Reach

Gravel bed material, very small slope, very wide, dominated by bedforms, boulders, cobbles, large wood, banks

Braided Stream Reach

variable material,

Channelized Debris Flow (Disturbance Regime)

Material stored in channel upstream breaks down, creating avalanche in high magnitude down stream channel. Wipes down structure of original downstream carrying debris with it, until gradient is low enough that it can be deposited. Occurs as a result of high impact events such as flooding

Debris flow

Debris movement from surrounding slope forming mass flows

Channelized Stream Reach

Created by human disturbance by which streams are recreated to float logs to mills. Streams are hit with dynamite to remove bedrock, boulders, and large wood to create a straight ditch

Microhabitat

Dependent on scale of organism. Otherwise defined as the substrates (mineral or wood) that provide adequate energy sources, temperature/humidity, and/or cover for particular organisms

Minerals

Rocks and inorganic particles providing adequate pH or surfaces to hang on to in avoidance of being washed away

Functions of wood

1. Creates steps = plunge pools

2. Backs up finer sediments, forming locally gentle slopes and spawning gravels

3. Increases channel stability

4. At edge, creates back eddies (swirling of water in reverse current to turbulent flow. Space of water that does not move downstream) and scour pools (pool hollowed out by water under pressure, leaves a cave)

5. Security cover for fish from predator and turbulent flow

6. Source of food for detritivores (fungi and bacteria) and some invertebrates

7. Traps leaves and smaller particles of organic matter

Large wood

Role - store sands and rocks that build up behind jammed log
Provides shading \= decreases temperature and algae bloom
Security cover from predators and food source
Carbon source \= fungi digest cellulose and becomes fungal biomass as food source or biophyll from algae
Creates heterogenous (age) islands, thus increasing biodiversity

Small wood

Create sieve by interacting with other small wood. Catches leaves, seeds, fruits and traps these materials to create structure for food web streams

Imbrication

locking of mixed materials together, more rocks that enter makes the structure it creates (stone net) harder to move. They are held by attractive and gravitational forces.

Stone nets

Rock structure created by imbrication by which a congregation of rocks are held together by gravitational and attractive forces. Only formed in the absence of disturbance that would otherwise wash away the rocks. Creates higher biodiversity, and greater stream bed stability

Greater stream bed stability is related to what type of force?

Resistance to tractive forces

How do salmon act as geomorphic agents? How does this contribute to overall stream ecology? What is this dependent on?

Depths of burial and travel distance of the material that is moved during spawning is almost equivalent to the amount of material that is moved during low flow snowmelt events.

Re-arrange the rocks that create microhabitats and form alternative habitats that other organisms may like.

Dependent on number of effective female spawners at the spawning stream

Hydraulic Habitat and micro habitats for caddis flies

Caddis flies stick to top of rock at which the flow is at it's highest velocity to catch smaller bugs. Positioning based on the force and turbulence of flow

Water quality comprised of?

1. Adequate temperature

2. Water solutions (sediment, nutrients)

3. Oxygen content

Why is temperature considered the master variable?

Affects rate of chemical and metabolic reactions (thus, rates of biological processes)

Water density related to temperature (Highest density at 4 degrees)

Determines oxygen concentration - as temperature increases, oxygen concentration decreases

Thermal Energy Inputs

1. Shortwave radiation - direct solar radiation from atmosphere to surface.

• Lakes: shortwave only heats up top layer as it is most exposed to sky and heats up very quickly (thermal stratification)

• Canopied Streams: SWR intercepted and top layer is not heated

2. Groundwater inflow - comes in at 8 or 9 degrees, serving as a moderator in streams. This temperature makes groundwater fed streams cooler in the summer and warmer in the winter

3. Advection - Water temperatures coming from upstream reaches to downstream reaches

Why is water being most dense at 4 degrees useful?

At 4 degrees, water has highest density. Bottom of lake remains 4 degrees and only top layer forms ice - the high density makes ice float.

This enables aquatic organisms to live at the bottom of the lake and avoid cells freezing in winter

Physiological adaptation to avoid freezing?

Cells of aquatic organisms have solutes serving as an anti freeze that can be adjusted.

What is water super cooling?

Water can be less than zero degrees, but have no ice formation due to the high velocity of the stream. Any point at which water slows down (e.g. right at top over any type of surface) forms anchor ice. Thus surfaces of rocks in bottom of stream are covered in ice but rest of river is not frozen.

Temperature and Specific Growth Rates

Highest at a species-specific optimal growth temperature at which the organism can adequately meet metabolic needs.

Upper Lethal limits

metabolic rates increase so fast that other parts of the organism cannot keep up with the metabolic needs at this temperature.

Dependent on species type and upper lethal temperature exposure length or activity levels

Increase exposure time \= lethal
Increase activity level \= lethal

When can an organism maybe survive it's upper lethal limits?

When the exposure rate to this temperature is low and/or when the organism is at rest

Lower growth Limits

Temperature at which growth rate \= zero. Dependent on species.

Why is growth slow?

Because only small portion of the year has an optimal growth temperature - within any given year there is more consistently colder temperatures, making growth slow.

What determines temperature variations?

1. Bed heterogeneity

2. Diel cycles (period of 24 hours)

3. Annual cycles

4. El Nino Southern Oscillations - recurring climate pattern involving changes in the temperatures of water in the central and eastern tropical Pacific Ocean

5. Pacific Decadal Oscillations - recurring pattern of ocean-atmosphere climate variability over the mid-latitude Pacific basin.

Temperature ranges in small streams

Decreased solar energy inputs due to canopy interception. Tend to be cooler and less variable in temperature because of the canopy cover (with no human disturbance) and increased groundwater inputs

Temperature ranges in large streams

increased solar energy (only edges covered by canopy). Fast cooling/heating

Temperature ranges in very large streams

Ratio of solar energy to VOLUME is very small (too much volume per amount of SW input), thus very large rivers have very slow cooling/heating.

Rely on thermal inputs via advection from warmer upstream reaches.

How can we manage stream temperature?

With vegetation cover!

How are specific growth rates highly state dependent?

Not only dependent on external temperature, but also:

• acclimation time: longer time exposed to temperature, better performance

• population density

• predator availability

• species

• age class

• food availability

How does stress change specific growth rates? Why?

Increase stress \= decrease optimal growth temperature range
Decrease stress/optimal conditions for other factors \= increase optimal growth temperature range

Because when stressed, organisms spend more energy for any given activity, and are more sensitive to any given change in temperature.

Ex. Optimal growth rates are highest when fish have high food availability. Lowest when fish are starving because they are more sensitive to temperature changes

Temperature Thresholds and forest management

Temperature threshold varies with regions - no one temperature range suiting all populations of all species.

Thus, management should focus primarily on canopy maintenance to decrease temperature of streams

When is oxygen concentration a problem?

In non-flowing water bodies such as lakes, wetlands, etc. due to no re-aireation as a result of the lack of turbulence

Adaptations of aquatic organisms to maximize oxygen absorption?

1. may flies have expansions/flaps of body that form gills to enhance water access to internal body

2. caddisfly builds cases with undulations to expose hidden abdomen to water to increase oxygen absorption

3. stoneflies have tufts of gills to increase surface area off of which oxygen may be exchanged

Where is oxygen concentrated in lakes and wetlands?

oxygen diffusion mainly at top. At bottom, decreased oxygen diffusion due to the increased presence of algae and dead debris

Turbidity

measure of interception of light by particles of suspended sediment (both suspended organic particles and suspended inorganic particles)

How clear/muddy water is

comes from agriculture, roads, large floods (mass wasting), or any other soil disturbance

How does turbidity affect organisms?

• prevents organisms from seeing food

• can clog gills due to increased suspended sediment especially in fish with mucus covered gills

• smothers/buries fish eggs, decreasing oxygen diffusion from water to eggs

• fill in spaces for invertebrate habitat

• may be ingested by fish

• whereby part of the suspended sediment is organic, this increases oxygen demand and thus competition for already low oxygen levels

How does turbidity affect plant life?

• Any plants at the bottom of a lake/stream are negatively impacted by high turbidity because suspended sediment covers photosynthetic area

• reduces light penetration

• abrades algae/biophyll growing on rocks

total suspended solids

total suspended organic and inorganic sediments

biological oxygen demand

process by which turbidity introduces organic particles (forest soils, sewage outfalls, pulp mills) that deplete the oxygen in the water because bacteria and other organisms use up the oxygen in decomposing organic materials

fine particulate organic matter

suspended organic particles. Contribute to interception of light similar to that of inorganic particles

dissolved organic matter/dissolved organic carbon

contribute to filtering of light - anything that passes through a filter paper with a pore size of 0.63 nanometers

intercept UV (esp UVB) that otherwise causes genetic damage in cells

intercept light and can lead to increasing water temperature by absorbing light in the water itself

Aspects of water - pH

Closely related to acidity of water

Waters are buffered by carbonate-bicarbonate system - allows acid in rain to bind with Calcium ions and other salts - this varies dependent on geology.

How does geology impact water pH?

Some rock types release more calcium ions, thus serve a better buffering system against acidity of rain

Does the coast have a good buffer system?

No. Our water here is very susceptible to changes in rain pH. This is because there is low calcium ion content within granite (dominant geology).

What processes does pH impact?

1. water hardness - Measure of high solute concentrations. Hard water has more solutes such as calcium ions, thus higher pHs due to buffer system. revealed as calcareous coating

2. Conductivity - potential for water to conduct an electric current. Higher mineral/salt concentration in water = high pH = high conductivity

How does nutrient composition impact streams?

Contribute to the nutrition of primary producers and other organisms.

Concentrations determine productivity of environments

Important nutrients: Nitrogen, Phosphorous, Potassium, Calcium, Iron.

Nitrogen and phosphorous ratio

Phosphorous/nitrogen ratio determines what nutrients are limiting

Ex. coastal range has negligible amounts of phosphorous due to granite dominated geology - phosphorous is a limiting factor

ex. N in N/P ratio may be limiting when trees take up large amounts of nitrogen from water

what is nitrogen and phosphorous important for?

1. N = proteins and enzymes

2. P = genetic material, ATP and bone

what forms are these two nutrients most commonly used?

nitrate (NO3), ammonium (NH3), and phosphate (PO4)

What nutrient ratio can be used to measure food quality?

C:N ratio. High C:N \= low nitrogen content, thus poorer food quality

Stable Isotope Analysis

looks at diets

ex. use stable isotope N15 to determine where salmon have travelled/came from as N15 comes from ocean

-\> C15 presence vs. N15 presence tells you whether the salmon came most recently from the sea, terrestrial, or freshwater sources

Nutrient spiralling

organisms hold onto nutrients especially if such nutrient is limiting. This nutrient is released via urine or feces and it spirals rather than flowing straight downstream. Spiralling is dependent on volume and velocity of flow

where are contaminants stored in water?

stored in water itself or in fat in organisms

bioaccumulation (define and example)

process by which an ingested contaminant increases in toxicity and concentration as it moves up the food chain

ex. mercury ends up in lake/wetland. Turns anoxic due to low oxygen. Bacteria convert mercury to methylate - very toxic now.