Bridging the Gaps:Wood Across Time & Space

in Diverse Rivers

Ellen WohlColorado State University

Goal: For a river reach anywhere in the world, quantitatively predict

So, what are the knowledge gaps that keep us from doing this?

3) geomorphic & ecological effects of wood

1) all aspects of wood budget (Inputs, Storage, Outputs)

2) fluctuations in all parameters through time & space

I. Wood Budget:Components of Geomorphic & Biotic Context

forest dynamics

hillslope dynamics

channel dynamicsvalley-bottom dynamics

network (tributary) dynamics

biota (beaver)

Forest dynamics Stand characteristics (spatial density, tree age & size, species composition)Mortality (individual, mass – fire, insects, windstorm)

Hillslope dynamics Mass movements (debris flows, landslides, avalanches) that recruit trees

Channel dynamics

Valley-bottom dynamics

Network dynamics Tributary inputs of wood, water, sediment

Floodplain storage of wood, water, sediment

Wood transport, bank erosion, water & sediment discharges

Biota (beavers)

Wood recruitment & stabilization, formation of secondary channels

Components of Wood Budget

Qo

Qi

LoLi

D

S

ΔS =[Li – Lo + Qi/Δx – Qo/Δx – D + B] Δt

B

Benda & Sias, 2003

Li = Im + If + Ibe + Is + Ie

chronicforest mortality

tree topple,fire &windstorm

exhumationof buriedwood

massmovements

bankerosion

Benda & Sias, 2003

Early numerical simulations focused on recruitment (Beechie et al., 2000; Bragg, 2000; Welty et al., 2002; Gregory et al., 2003)

Knowledge gap:Diverse models have end prediction of storage, but need much more

region-specific calibration & testingNeed more effective consideration of how stable wood influences

wood in transport or how multiple pieces affect individual/collectivemobility

More recent models focus on

• forces acting on wood (Merten et al., 2010; Rafferty, 2013)

• stochastic prediction of wood load (Eaton et al., 2012)

• wood loads & related physical processes (Lancaster et al. 2003)

North St. Vrain Creek

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000 8500 9000

Wood load (

m3/h

a)

0

100

200

300

400

500

600

700

gorge

avg 49

fan avg 405

alternating anastomosing & small gorges

avg 79

anastomosingavg 192

occasional anastomosing

avg 85

single channel

avg 13

North St. Vrain jams

Cumulative distance downstream (m)

0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000 8500 9000

Volu

me o

f w

ood in jam

(m

3)

0

2

4

6

8

10

12

14

16

avg 0.3

avg 1.1

avg 1.5

avg 0.8

avg 1.4avg 0.2

Wohl & Cadol, 2011

Cumulative distance downstream (m)

North St. Vrain Creek, Colorado, USA

singlechannel

singlechannel

alternating single & multiple channelsmultiplechannels

II. Temporal & spatial fluctuations: space

ΔSc = [Li – L0 + Qi/Δx – Q0/Δx – D + B]Δt

Li = Im + If + Ibe + Is + Ie

ΔSc = [Li – L0 + Qi/Δx – Q0/Δx – D + B]ΔtLi = Im + If + Ibe + Is + Ie

ΔSc = [Li – L0 + Qi/Δx – Q0/Δx – D + B]ΔtLi = Im + If + Ibe + Is + Ie

confined headwaters

unconfined headwaters

lower basin

Wohl, 2011a

Abbe & Montgomery, 2003

recruitmentmechanism

typical position inchannel networkIN-SITU COMBINATION TRANSPORT

landsliding

bank erosion

low order, steep

2nd – 4th order0.02 < S < 0.20

> 3rd orderS < 0.03

large alluvial channelsS < 0.01

Obliquelog steps

Bankinput

Orthogonallog steps

Valley

FlowDeflection

BarApex

Meander

Rafts

bench

alterschannel

alterschannel

alterschannel

noeffect

noeffect

noeffect

widecontinuous

moderatecontinuous

widecontinuous

narrowdiscontinuous

Longitudinal & lateral extent of floodplainWohl, 2014

Knowledge gap:Within a region, lack of data on downstream trends in wood load in

unaltered rivers with drainage areas exceeding ~ 300 km2

(Fox & Bolton, 2007)

Knowledge gap:Between regions, limited data for full climatic-biotic range in temperatezone, & very limited data for tropics & boreal zones

CR = La Selva, Costa Rica WA1= Western WashingtonWA2 = Western Washington WA3 = Cascade Range, WAOR1 = Western OregonOR2 = Coast Range, Oregon

AK = Southeast AlaskaBC = SW British ColumbiaMI = Northern MichiganCO1 = Front Range, ColoradoCO2 = Front Range, ColoradoWY1 = Bighorn Range, Wyoming

WY2 = Absaroka Range, WYWY3 = Bridger-Teton NF, WYSA = Southern Andes, ChileTF = Tierra del Fuego, ArgentinaAU = Southeast AustraliaNZ = South Island, New Zealand

Cadol et al., 2009

Pacific Northwest Southern Rockies

boreal

temperate

tropical

low, transient wood loads (rapid decay, mobile)

(Wohl et al., 2012)

wood highly variable between sites

??? maybe moderateto high wood loads

Locations of field studies on instream wood published in English-language journals

Arctic circle

Tropic of Cancer

Tropic of Capricorn

Relative dearth of studies in high and low latitudes

East St. Louis Creek

left bank

flow

0

10 m

10 m1996

left bank

flow

0

10 m2006

19961997199819992000200120022003200420052006

Wohl & Goode, 2008

Measured short-term fluctuations

Temporal fluctuations

Channel-spanning logjams in Rocky Mountain National Park, USA

2010

Days since 1 May

0 50 100 150

Dis

ch

arg

e (

m3

/s)

0

5

10

15

20

25

2011

Days since 1 May

0 50 100 150D

isch

arg

e (

m3

/s)

0

5

10

15

20

25

2012

Days since 1 May

0 50 100 150

Dis

ch

arg

e (

m3

/s)

0

5

10

15

20

25

2013

Days since 1 May

0 50 100 150

Dis

ch

arg

e (

m3

/s)

0

5

10

15

20

25

2014

Days since 1 May

0 50 100 150

Dis

ch

arg

e (

m3

/s)

0

5

10

15

20

25

Year

2010 2011 2012 2013 2014

Nu

mber

of ja

ms

0

20

40

60

80

100

120

140

NSV

Ouzel

Cony

Hunters

blowdown flood

high, short peak high, long peak no peak autumn flood normal year

Wohl, 2011a

0

50

0

100 200 300 400

100

150

200

250

Time (years)

Longer term fluctuations in wood load on forest floorColorado Front Range

Knowledge gap:Relatively little published on temporal fluctuations of wood withina river segment or drainage basin, & particularly for unmanagedrivers (e.g., Gurnell & Sweet, 1998 & Lassettre et al., 2008 for managed rivers)

III. Geomorphic & ecological effects of wood: geomorphic

• reach-scale within channel• hydraulics & local scour (Shields & Smith, 1992; Mutz, 2003)

• sediment transport (Brooks et al., 2003)

• forced alluvial bed (Montgomery et al., 1996)

• wood, vegetation & planform (Gurnell et al., 2012)

• reach-scale across valley bottom• log jams & avulsions (Phillips, 2012)

• multi-thread channels (Wohl, 2011b) & floodplain large wood cycle (Collins et al., 2012)

Meandering

Anastomosing

Braided

Forestchronosequence

Abandoned channel/oxbow

Ephemeral patches ofpioneer vegetation

Channel

In-channelwood jam

Mature forestpatches

Buriedwood jam“hardpoint”

Secondary channel

Frequently-shifting channels

Avulsionaroundhardpoints

Migrationbetweenhardpoints

Channel migration

Collins et al., 2012

Knowledge gaps:

• quantifying flow resistance & obstruction –numerous case studies in field & flumes (e.g., Young, 1991;

Shields & Gippel, 1995; Dudley et al., 1998; Manga & Kirchner, 2000; Wallerstein et al., 2001; Curran & Wohl, 2003; Hygelund & Manga, 2003; Wilcox & Wohl, 2006; Wilcox et al., 2006; Daniels & Rhoads, 2007;

Manners et al., 2007) –but no widely applicable formula or technique

Knowledge gaps:

• quantifying sediment storage –numerous case studies (e.g., Megahan, 1982; Klein et al., 1987;

Bugosh & Custer, 1989; Nakamura & Swanson, 1993; Smith et al., 1993; Thompson, 1995; Hart, 2002; Haschenburger & Rice, 2004; Fisher et al., 2010;

Ryan et al., 2014) & numerical models for particular river systems(e.g., Lancaster et al., 2003; Eaton et al., 2012)

• no broadly applicable conceptual model

Drainage area (km2)

Sto

red

sed

imen

t p

er

un

it a

rea

of

chan

ne

ljammed steps &

sediment wedges

dispersedwood & sediment

wood rafts &floodplain sediment

Drainage area (km2)

0 50 100 150 200

Sedim

ent

volu

me (

m3/h

a)

0

1000

2000

3000

4000

5000

6000

other

jammed steps

Wohl & Scott (in review)

Spearman correlation coefficient = 0.89

102 104

Knowledge gaps:

• documentation of potential alternative stable stables • wood-rich vs wood-poor (Wohl & Beckman, 2014)

• high vs diminished biogeomorphic complexity of floodplain(Collins et al., 2012)

• linear vs threshold effects of wood load (e.g., Wohl, 2011b; Beckman & Wohl, 2014a)

• potential for emergent properties (e.g., anastomosing channels)

• effects of dramatic historical reductions in wood loads

Ecological effects

• reach-scale within channel• habitat abundance & diversity

(Carlson et al., 1990; Richmond & Fausch, 1995)

• enhanced nutrient storage & uptake (Buckley & Triska, 1978; Ward & Aumen, 1986; Beckman & Wohl, 2014b)

• greater biomass (Gowan & Fausch, 1996; Nagayama et al., 2012)

• reach-scale across valley bottom• floodplain habitat abundance & diversity (Harmon et al., 1986)

• floodplain nutrient storage & uptake (Naiman et al., 2010)

• floodplain biomass (Benke, 2001)

Ongoing “Leaky Rivers” project research indicates greater wood loads& measures of physical complexity are associated with

greater nutrient uptakegreater insect predator (fish, riparian spiders) biomass & diversity

Knowledge gaps:

• linear versus threshold effects for habitat, diversity, and/or biomass

• is wood ecologically important where transient (tropics)?

• potential for emergent properties

• effects of dramatic historical reductions in wood loads

Additional knowledge gaps

• effective level of instream wood to create desired environmentaleffects (e.g., linear or threshold?) – ELJs (Abbe & Brooks, 2011; Gallisdorfer et al., 2014)

• big rivers

• most areas outside of Pacific Northwest

• effect of wood loads on wood transport (we have a start with existing

numerical models (Eaton, Lancaster) & flume studies (Braudrick & Grant, 2000, 2001; Bocchiola et al., 2006)

• temporal variation (HRV or NRV)

• how to effectively reintroduce/manage wood

• education/outreach for river restoration & management to counternegative perceptions (Chin et al., 2008)

For a river reach anywhere in the world, quantitatively predict

• all aspects of wood budget (I, S, O)• fluctuations through time & space• geomorphic & ecological effects of wood

Need • more case studies from diverse environments

• syntheses, meta-data, conceptual models, & numerical simulations for

hydraulicssediment dynamicschannel & floodplain morphologyecological effects (habitat, nutrients, thresholds leading to

alternative stable states)

• education & outreach on benefits of wood

how much?stable? mobile?

effects: linear, threshold?

fluctuations through time?

time

time

References Cited

Abbe T, Brooks A. 2011. Geomorphic, engineering, and ecological considerations when using wood in river restoration. In, A Simon, SJ

Bennett, JM Castro, eds., Stream Restoration in Dynamic Fluvial Systems: Scientific Approaches, Analyses, and Tools. American

Geophysical Union Press, Washington, D.C., pp. 419, 451.

Abbe TB, Montgomery DR. 2003. Patterns and processes of wood debris accumulation in the Queets River basin, Washington.

Geomorphology 51, 81-107.

Beckman ND, Wohl E. 2014a. Effects of forest stand age on the characteristics of logjams in mountainous forest streams. Earth Surface

Processes and Landforms 39, 1421-1431.

Beckman ND, Wohl E. 2014b. Carbon storage in mountainous headwater streams: the role of old-growth forest and logjams. Water

Resources Research 50, 2376-2393.

Beechie TG, Pess G, Kennard P, Bilby RE, Bolton S. 2000. Modeling recovery rates and pathways for woody debris recruitment in

northwestern Washington streams. North American Journal of Fisheries Management 20, 436-452.

Benda LE, Sias JC. 2003. A quantitative framework for evaluating the mass balance of in-stream organic debris. Forest Ecology and

Management 172, 1-16.

Benke AC. 2001. Importance of flood regime to invertebrate habitat in an unregulated river-floodplain ecosystem. Journal of the North

American Benthological Society 20, 225-240.

Bocchiola D, Rulli MC, Rosso R. 2006. Transport of large woody debris in the present of obstacles. Geomorphology 76, 166-178.

Bragg DC. 2000. Simulating catastrophic and individualistic large woody debris recruitment for a small riparian system. Ecology 81, 1382-

1394.

Braudrick CA, Grant GE. 2000. When do logs move in rivers? Water Resources Research 36, 571-583.

Braudrick CA, Grant GE. 2001. Transport and deposition of large woody debris in streams: a flume experiment. Geomorphology 41, 263-

283.

Brooks AP, Brierley GJ, Millar RG. 2003. The long-term control of vegetation and woody debris on channel and flood-plain evolution:

insights from a paired catchment study in southeastern Australia. Geomorphology 51, 7-29.

Buckley, Triska. 1978. International Vereinigung Theoretische und Angewandte Limonologie Verhandlungen 20, 1333-1339.

References Cited (continued)

Bugosh N, Custer SG. 1989. The effect of a log-jam burst on bedload transport and channel characteristics in a headwater stream. In, DF

Potts, WW Woessner, eds., Headwaters Hydrology, American Water Resources Association, Bethesda, MD, pp. 203-211.

Cadol D, Wohl E, Goode JR, Jaeger KL. 2009. Wood distribution in neotropical forested headwater streams of La Selva, Costa Rica. Earth

Surface Processes and Landforms 34, 1198-1215.

Carlson JY, Andrus CW, Froehlich HA. 1990. Woody debris, channel features, and macroinvertebrates of streams with logged and

undisturbed riparian timber in northeastern Oregon, USA. Canadian Journal of Fisheries and Aquatic Sciences 47, 1103-1111.

Chin A, Daniels MD, Urban MA et al. 2008. Perceptions of wood in rivers and challenges for stream restoration in the United States.

Environmental Management 41, 893-903.

Collins BD, Montgomery DR, Fetherston KL, Abbe TB. 2012. The floodplain large wood cycle hypothesis: a mechanism for the physical and

biotic structuring of temperate forested alluvial valleys in the North Pacific coastal ecoregion. Geomorphology 139-140, 460-470.

Curran JH, Wohl EE. 2003. Large woody debris and flow resistance in step-pool channels, Cascade Range, Washington. Geomorphology

51, 141-157.

Daniels MD, Rhoads B. 2007. Influence of experimental removal of large woody debris on spatial patterns of three-dimensional flow in a

meander bend. Earth Surface Processes and Landforms 32, 460-474.

Dudley et al. 1998. Journal of the American Water Resources Association 34, 1189-1197.

Eaton BC, Hassan MA, Davidson SL. 2012. Modeling wood dynamics, jam formation, and sediment storage in a gravel-bed stream. Journal

of Geophysical Research 117, F00A05, doi:10.1029/2012JF002385.

Fisher GB, Magilligan FJ, Kaste JM, Nislow KH. 2010. Constraining the timescales of sediment sequestration associated with large woody

debris using cosmogenic 7Be. Journal of Geophysical Research 115, F01013.

Fox M, Bolton S. 2007. A regional and geomorphic reference for quantities and volumes of instream wood in unmanaged forested basins

of Washington State. North American Journal of Fisheries Management 27, 342-359.

Gallisdorfer MS, Bennett SJ, Atkinson JF, Ghaneeizad SM, Brooks AP, Simon A, Langendoen EJ. 2014. Physical-scale model designs for

engineered log jams in rivers. Journal of Hydro-environment Research 8, 115-128.

Gippel. 1995. Journal of Environmental Engineering 121, 388-394.

References Cited (continued)

Gowan C, Fausch KD. 1996. Long-term demographic responses of trout populations to habitat manipulation in six Colorado streams.

Ecological Applications 6, 931-946.

Gregory et al. 2003. American Fisheries Society Symposium 37, 315-335.

Gurnell AM, Sweet R. 1998. The distribution of large woody debris accumulations and pools in relation to woodland stream management

in a small, low-gradient stream. Earth Surface Processes and Landforms 23, 1101-1121.

Gurnell AM, Bertoldi W, Corenblit D. 2012. Changing river channels: the roles of hydrological processes, plants and pioneer fluvial

landforms in humid temperate, mixed load, gravel bed rivers. Earth-Science Reviews 111, 129-141.

Harmon ME, Franklin JF, Swanson FJ, Sollins P, Gregory SV, Lattin JD, Anderson NH, et al. 1986. Ecology of coarse woody debris in

temperate ecosystems. Advances in Ecological Research 15, 133-302.

Hart EA. 2002. Effects of woody debris on channel morphology and sediment storage in headwater streams in the Great Smoky

Mountains, Tennessee-North Carolina. Physical Geography 23, 492-510.

Haschenburger JK, Rice SP. 2004. Changes in woody debris and bed material texture in a gravel-bed channel. Geomorphology 60, 241-267.

Hygelund B, Manga M. 2003. Field measurements of drag coefficients for model large woody debris. Geomorphology 51, 175-185.

Klein R, Sonnevil R, Short D. 1987. Effects of woody debris removal on sediment storage in a northwest California stream. In, RL Beschta,

T Blinn, GE Grant, FJ Swanson, GG Ice, eds., Erosion and Sedimentation in the Pacific Rim. IAHS Publication no. 165, Wallingford, UK, pp.

403-404.

Lancaster ST, Hayes SK, Grant GE. 2003. Effects of wood on debris flow runout in small mountain watersheds. Water Resources Research

39, 1168, doi:10.1029/2001WR001227.

Lassettre et al. 2008. Earth Surface Processes and Landforms 33, 1098-1112.

Manga M, Kirchner JW. 2000. Stress partitioning in streams by large woody debris. Water Resources Research 36, 2373-2379.

Manners RB, Doyle MW, Small MJ. 2007. Structure and hydraulics of natural woody debris jams. Water Resources Research 43, W06432,

doi:10.1029/2006WR004910.

Megahan WF. 1982. Channel sediment storage behind obstructions in forested drainage basins draining the granitic bedrock of the Idaho

Batholith. In, FJ Swanson, RJ Janda, T Dunne, DN Swanston, eds., Sediment Budgets and Routing in Forested Drainage Basins. USDA Forest

Service General Technical Report PNW-141, pp. 114-121.

References Cited (continued)

Merten et al. 2010. Water Resources Research 46, W10514.

Montgomery DR, Abbe TB, Peterson NP, Buffington JM, Schmidt KM, Stock JD. 1996. Distribution of bedrock and alluvial channels in

forested mountain drainage basins. Nature 381, 587-589.

Mutz M. 2003. Hydraulic effects of wood in streams and rivers. In, SV Gregory, KL Boyer, AM Gurnell, eds., The Ecology and Management

of Wood in World Rivers. American Fisheries Society, Bethesda, MD, pp. 93-107.

Nagayama et al. 2012. Hydrobiologia 680, 159-170.

Naiman et al. 2010. Ecosystems 13, 1-31.

Nakamura F, Swanson FJ. 1993. Effects of coarse woody debris on morphology and sediment storage of a mountain stream system in

western Oregon. Earth Surface Processes and Landforms 18, 43-61.

Phillips JD. 2012. Log-jams and avulsion in the San Antonio River delta, Texas. Earth Surface Processes and Landforms 37, 936-950.

Rafferty M. 2013. MS thesis, Colorado State University.

Richmond AD, Fausch KD. 1995. Characteristics and function of large woody debris in subalpine Rocky Mountain streams in northern

Colorado. Canadian Journal of Fisheries and Aquatic Sciences 52, 1789-1802.

Ryan SE, Bishop EL, Daniels JM. 2014. Influence of large wood on channel morphology and sediment storage in headwater mountain

streams, Fraser Experimental Forest, Colorado. Geomorphology 217, 73-88.

Shields FD, Smith. 1992. Aquatic Conservation: Marine and Freshwater Ecosystems 2, 145-163.

Shields FD, Gippel CJ. 1995. Prediction of effects of woody debris removal on flow resistance. Journal of Hydraulic Engineering 121, 341-

354.

Smith RD, Sidle RC, Porter PE. 1993. Effects on bedload transport of experimental removal of woody debris from a forest gravel-bed

stream. Earth Surface Processes and Landforms 18, 455-468.

Thompson DM. 1995. The effects of large organic debris on sediment processes and stream morphology in Vermont. Geomorphology 11,

235-244.

Wallerstein et al. 2001. Earth Surface Processes and Landforms 26, 1265-1283.

References Cited (continued)

Ward GM, Aumen NG. 1986. Woody debris as a source of fine particulate organic matter in coniferous forest stream ecosystems.

Canadian Journal of Fisheries and Aquatic Sciences 43, 1635-1642.

Welty JJ, Beechie T, Sullivan K, Hyink DM, Bilby RE, Andrus C, Pess G. 2002. Riparian aquatic interaction simulator (RAIS): a model of

riparian forest dynamics for the generation of large woody debris and shade. Forest Ecology and Management 162, 299-318.

Wilcox AC, Wohl E. 2006. Flow resistance dynamics in step-pool channels: 1. Large woody debris and controls on total resistance. Water

Resources Research 42, W05418, doi:10.1029/2005WR004277.

Wilcox AC, Nelson JM, Wohl EE. 2006. Flow resistance dynamics in step-pool channels: 2. Partitioning between grain, spill, and woody

debris resistance. Water Resources Research 42, W05419, doi:10.1029/2005WR004278.

Wohl E. 2011a. Seeing the forest and the trees: wood in stream restoration in the Colorado Front Range, United States. In, A Simon, SJ

Bennett, JM Castro, eds., Stream Restoration in Dynamic Fluvial Systems: Scientific Approaches, Analyses, and Tools. American

Geophysical Union Press, Washington, D.C., pp. 399-418.

Wohl E. 2011b. Threshold-induced complex behavior of wood in mountain streams. Geology 39, 587-590.

Wohl E. 2014. Floodplains and wood. Earth-Science Reviews 123, 194-212.

Wohl E, Beckman ND. 2014. Leaky rivers: implications of the loss of longitudinal fluvial disconnectivity in headwater streams.

Geomorphology 205, 27-35.

Wohl E, Cadol D. 2011. Neighborhood matters: patterns and controls on wood distribution in old-growth forest streams of the Colorado

Front Range, USA. Geomorphology 125, 132-146.

Wohl E, Goode JR. 2008. Wood dynamics in headwater streams of the Colorado Rocky Mountains. Water Resources Research 44,

W09429, doi:10.1029/2007WR006522.

Wohl E, Scott D. in review. Wood and sediment storage and dynamics in river corridors. Earth Surface Processes and Landforms.

Wohl E, Bolton S, Cadol D, Comiti F, Goode JR, Mao L. 2012. A two end-member model of wood dynamics in headwater neotropical rivers.

Journal of Hydrology 462-463, 67-76.

Young MK. 1991. Regulated Rivers: Research and Management 6, 203-211.