michael m. pollock · [email protected] 2 . [email protected] 3 ....

Michael M. Pollock NOAA Fisheries-Northwest Fisheries Science Center, Seattle Washington

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Natural Selection Species and Individuals compete with each other There is natural genetic variation within a population Most individuals die before reproducing Individuals with genetics best suited for current

environmental conditions will survive The characteristics, behavior and genetics of species

changes as natural selective pressures change Non-equilibrium conditions allow more species to

co-exist Environmental variation and the coexistence of species Disturbance and the coexistence of species Intermediate Disturbance Hypothesis Dynamic Equilibrium Model of species coexistence Principle of Competitive Exclusion / L-V equations

(stability = fewer species)

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The elements that define riverine habitats tend to persist in natural river systems (and are constrained or eliminated by human alteration), and that the distribution of the habitat patches (mosaics) changes spatially over time due to primary drivers, particularly flooding, channel avulsion, cut and fill alluviation (erosion and deposition of fine and coarse sediments), deposition of wood recruitment and regeneration of riparian vegetation. Stanford et al. 2005.

Channel slope Valley confinement

Discharge

Sediment supply, Sediment size

Factors Controlling Channel Formation

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Beechie , unpublished

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From Palmer 2010 10

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“Gravel-bedded streams are thought to have a characteristic meandering form bordered by a self-formed, fine-grained floodplain. This ideal guides a multibillion-dollar stream restoration industry. We have mapped and dated many of the deposits along mid-Atlantic streams that formed the basis for this widely accepted model. These data, as well as historical maps and records, show instead that before European settlement, the streams were small anabranching channels within extensive vegetated wetlands that accumulated little sediment but stored substantial organic carbon.”-Walter and Merritts 2008.

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From Cluer and Thorne 2014 See also Walter and Merritts 2008

Stream Evolution Models add vertical component

From Pollock et al. 2014 14

Create a three-dimensional shifting mosaic,

a structurally complex, biologically diverse habitat

15 From Pollock et al. 2014

From Pollock et al. 2014

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Dams Can Substantially Accelerate Recovery

The concept of channel form equilibrium: that a river channel’s form is self-adjusting to the

prevailing watershed conditions that control the amount of sediment and water delivered to the channel and

that the dominant or effective discharge controls the size and shape of the channel and that

this discharge corresponds to bankfull discharge (the point at which flow leaves a channel and spreads out over the floodplain) and that such discharge occurs about 2 out of every 3 years.

That the channel is stable (sediment inputs = sediment outputs)


Dynamism is essential for biological diversity (disturbance, environmental variation, shifting mosaic, habitat complexity)

Stochastic outcomes (probability-based, not deterministic)

Natural selective pressures-

Most individuals die before reproducing

Natural variation occurs-those adapted to the existing conditions survive and reproduce

Species evolve (Life history strategies and behaviors change over time)

Focus on net long-term benefit to species and habitat, less concerned with short-term impacts or benefits (i.e. effects on individuals within a population)

Explicitly recognizes the interactions between biological and physical processes in the restoration process


Channel slope Valley confinement

Discharge




Beechie , unpublished

Channel slope

Discharge




Bank material

Vegetation

Beaver

Herbivores

Predators Valley confinement

Pollock, unpublished

Beaver Dams

Live Vegetation

Large Wood

Landslides

Alluvial Fans

Sea Level Rise

Tectonics


Increasing Time Scales

0.0%

20.0%

40.0%

60.0%

80.0%

100.0%

120.0%

010

020

030

040

050

060

070

080

090

010

00

Distance Traveled (m)

% S

ettle

d

Sediment retention: Beaver Dams v. Sedges

(Equation From Dabney et al. 1995)

Clay

> Silt

Sedge Aggradation Rate ~3 cm/yr

0

0.1

0.2

0.3

0.4

0.5

0 1 2 3 4 5 6

Age (yr)

Agg

rada

tion

rate

(m•y

r-1)

Pollock et al. 2007

Beaver Dam Aggradation Rate ~10-15 cm/yr

Silt deposition

00

5050

100100

150150

200200

250250

300300

350350

400400

450450

500500

550550

600600

650650

700700

750750

800800

850850

900900

950950

10001000

Ci/Co (%)

Distance Traveled (m)

% Settled

1

1

0.1353352832

0.9231163464

0.0183156389

0.852143789

0.0024787522

0.7866278611

0.0003354626

0.7261490371

0.0000453999

0.670320046

0.0000061442

0.6187833918

0.0000008315

0.5712090638

0.0000001125

0.527292424

0.0000000152

0.486752256

0.0000000021

0.4493289641

0.0000000003

0.4147829117

0

0.382892886

0

0.353454682

0

0.3262797946

0

0.3011942119

0

0.2780373005

0

0.256660777

2.31952283024357E-16

0.2369277587

3.13913279204803E-17

0.218711887

4.24835425529159E-18

0.201896518

Wetland Deposition Calcs

particle sizev (settling velocity m/s)wetland width mQ (discharge) m3/sq (discharge/unit width) m2/sx(distance traveled through wetland) mCo/Ci ratioc0/ci = e-(v/q)x

.001 (fine silt)1.00E-0230250.833333333310030.1%

.001 (fine silt)1.00E-023050.16666666671000.2%

.001 (fine silt)1.00E-021050.510013.5%

.001 (fine silt)1.00E-02101013074.1%

clay (bentonite)4.00E-0430100.3333333333100030.1%

x (m)Ci/Co (%)clay (bentonite)x (m)Ci/Co (%)

.001 (fine silt)1.00E-022050.250100.0%04.00E-042050.250100.0%

.001 (fine silt)1.00E-022050.255013.5%504.00E-042050.255092.3%

.001 (fine silt)1.00E-022050.251001.8%1004.00E-042050.2510085.2%

.001 (fine silt)1.00E-022050.251500.2%1504.00E-042050.2515078.7%

.001 (fine silt)1.00E-022050.252000.0%2004.00E-042050.2520072.6%

.001 (fine silt)1.00E-022050.252500.0%2504.00E-042050.2525067.0%

.001 (fine silt)1.00E-022050.253000.0%3004.00E-042050.2530061.9%

.001 (fine silt)1.00E-022050.253500.0%3504.00E-042050.2535057.1%

.001 (fine silt)1.00E-022050.254000.0%4004.00E-042050.2540052.7%

.001 (fine silt)1.00E-022050.254500.0%4504.00E-042050.2545048.7%

.001 (fine silt)1.00E-022050.255000.0%5004.00E-042050.2550044.9%

.001 (fine silt)1.00E-022050.255500.0%5504.00E-042050.2555041.5%

.001 (fine silt)1.00E-022050.256000.0%6004.00E-042050.2560038.3%

.001 (fine silt)1.00E-022050.256500.0%6504.00E-042050.2565035.3%

.001 (fine silt)1.00E-022050.257000.0%7004.00E-042050.2570032.6%

1.00E-022050.257500.0%7504.00E-042050.2575030.1%

1.00E-022050.258000.0%8004.00E-042050.2580027.8%

1.00E-022050.258500.0%8504.00E-042050.2585025.7%

1.00E-022050.259000.0%9004.00E-042050.2590023.7%

1.00E-022050.259500.0%9504.00E-042050.2595021.9%

1.00E-022050.2510000.0%10004.00E-042050.25100020.2%

Camp Ck Sed dep

Density of sediment

Camp Creek Measurements (Welcher 1993)100lb/ft3 * 35.31 ft 3/m3 * .4536 kg/lb

1.60E+00mt/m3

Site #Width (m)Depth (m)Approximate length (m)modified lengthVolume of segment (m^3)modified volume

1A19.65.6321.8255.035320.827983Bear Creek

6B25.65.0321.8255.041190.432634205 mi2 *626 ton/mi2* 2000 lb/ ton *1 mt/2205 lb

726.14.1603.5478.164580.5511651.16E+05mt

225.02.01086.3860.654315.043032Camp Ck is 180 mi2

3A20.34.3965.6765.084287.2667781.02E+05mt

411.43.2442.5350.616142.412789KW study area is 143585414 m2

918.13.0241.1191.013091.7103725.54E+01mi2

1216.84.5241.1191.018227.2144413.15E+04mt

1326.93.9362.1286.937987.930097total m3 sediment produced in a year

1420.85.9482.8382.559249.2469411.96E+04m3

Totals/avg21.15068.64015.7424392.333623213% clay in Bear Ck data for peak event

which was > 90% of sediment

therefore say 85% trapping efficiency

Years to fill Camp Creek Arroyo

2.54E+01

Beaver Restoration v.2.12.15


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If all the ice melts, >200 ft sea level rise • 1-4 foot rise predicted in

next 85 yr, but predicted rates keep increasing.

• Circa 5000 yrs for 200 foot rise (big error bars), but on the scale of the rise and fall of civilizations

• Need sediment to counteract rising seas.

National Geographic 2014


150 years ago, 5% of California was “wetlands”, mostly in the Central Valley, really more of a wetland-river complex.


Incorporating Ecological Theory into Stream Restoration PracticesWhat is Ecological Theory?Dynamic Equilibrium Model: Disturbance and productivity primary drivers of species diversitySpecies diversity is maximized at intermediate levels of disturbance and environmental fluctuationsBeaver ponds-spatially variable, frequently disturbed = high diversityMeanwhile, back at the ranch…Shifting habitat mosaicSlide Number 8Meanwhile, back at the ranch…Restoration consisted mostly of bank stabilization, instream habitat improvement and channel reconfiguration (2010)Slide Number 11Meanwhile, back at the ranch…The Stage Zero Channel as a Recovery GoalSlide Number 14BeaverSlide Number 16Meanwhile, back at the ranch…Priniciple of Fluvial GeomorphologyAdding Life To Fluvial GeomorphologySlide Number 20Slide Number 21How Does Life Build Stream Habitat?By Increasing Flow ResistanceContinuity of Sediment Transport �or �Habitat formation?�Obstructions that Cause DepositionSlide Number 26Landslides-Naches River, WA (Nile Valley)Slide Number 28Landslides Create Good Salmon HabitatSea Level Rise-�A Grade ChangerSacramento-San Joaquin Rivers- 150 ybpSlide Number 32Really Big Low Head Dams as Tide Barriers-�-St Petersburg-16 mi�Venice-1.5 mi (3 openings)�Carquinez Strait? -1 miQuestions?

michael m. pollock · [email protected] 2 . [email protected] 3 ....

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