EcogeomorphologyPatrick BelmontDepartment of Watershed Sciencespatrick.belmont@usu.edu

An increasingly interdisciplinary endeavor...

Wheaton et al. (2011)

Makes prediction challenging

Fuller et al. (2011)

Eco-geomorphology isn’t just a one-way relationship in whichsupply -> morphology -> organisms

Fuller et al. (2011)

Specific hydraulic conditions combined with abiotic precipitation, algal growth, trapping of organic material, and in-situ plant growth produce a positive feedback loop that alters hydraulics to further promote travertine growth.

Salant et al. (2011)

b) and c) show growth of low profilediatoms after 4 and 24 weeks, resp.

d), e) and f) show growth of filamentous green algae at 4, 12 and 16 weeks, resp.

Periphyton growth modulates hydraulics and amplifies rates of particle deposition and modulates particle infiltration

Cohesive strength from roots and soilrequired for formation of single-thread channels

Channel-vegetation feedbacks in Rio Grande

Dean and Schmidt, 2011

Channel narrowing

~1940

2008

Channel narrowing

~1940

2008

Channel narrowing

~1940

2008

Channel widthchanges over time

Flow magnitude and duration matter

Effects of the Twitchell Canyon wildfire on stream geomorphology and fish

habitat

Figures: Lee MacDonald

Controls on wildfire and post-fire erosionare reasonably well known

“Natural” wildfire is not always

bad for fishes

Example from PNW

How does geomorphology determine Bonneville cutthroat trout habitat?

Photo: Jim Whelan

How does geomorphology determine Bonneville cutthroat trout habitat?

How does geomorphology determine Bonneville cutthroat trout habitat?

• Cover– Undercut

banks– Wood

• Cool water• Velocity/

drought refugia– pools

• Food

Locations of impacts and implications for

habitat are difficult to predict

In Utah- Diverse terrain and tectonics- Low veg density, slow recovery- Monsoon effects- Erodible soils- Habitat degradation- Fragmented systems

Which parts of a stream network will respond strongly (+ or -) to wildfire?

When, where and how are fish population bottlenecks caused by geomorphic processes?

What are the ecological benefits/detriments of channel dynamism/stability (via sediment transport, wood recruitment, etc.)?

When, where and how do human management, natural landscape features, and stochastic events increase or decrease fish habitat vulnerability?

Big questions at the interface of fish ecology and geomorphology

Implications for fish metapopulation restoration and viability?

Effects of getting hotter and drier, invasives, fragmentation?

September 20th, 2010NASA Picture of the day

Pre-fire vegetation

Two-needle pinyon pine(Pinus edulis)

Rocky Mountain juniper(Juniperus scopulorum)

Gambel oak(Quercus gambelii)

Progressionof the

fire

Data: USFSAnimation: Shannon Belmont

Beaver Creek

1/3 burned at high severity

burned 45,000 acres

started by lightning strike

Fires within 500 km

How big was the TC fire?

10 Jun 2011 to 8 Oct 2011

7 May 2012 to 27 Sep 2012

Precip data from Storrar, 2013

Post-fire precipitation

P(1/2) ~ 75 mm/hr

Storrar, 2013

Post-firehillslope erosion and vegetation recovery

How can we predict the sign and severity of channel response?

Pre-firePost-fire

Water Depth

Avg Snowmelt Runoff

Freq

uenc

y (P

DF)

Water Depth

Base flow

Freq

uenc

y (P

DF)

Water Velocity

Mean annual flow

Freq

uenc

y (P

DF)

Temperature

Mean annual flow

Freq

uenc

y (P

DF)

f(dist downstream, riparian cover)

Hypothetical changes in habitat metrics pre- and post-fire

Grain Size

Channel bed surface

Freq

uenc

y (P

DF)

Turbidity

Time-integrated turbidity

Freq

uenc

y (P

DF)

Size of critical habitat patches

Freq

uenc

y (P

DF)

Geology of theTushar Mountains

Frac

tion

of sa

mpl

e po

ints

Stream Power Index (𝑆𝑆𝐴𝐴0.5)

Mapping incised channel heads

Drainage Area (m2)

Frac

tion

of sa

mpl

e po

ints

SLOPE = θ (~.3-.7)

Y-INTERCEPT = KS KSN

River longitudinal profiles𝑆𝑆 = 𝑘𝑘𝑠𝑠𝐴𝐴𝜃𝜃

FishShingle

BeaverSevier

River longitudinal profiles

Stream Profiler tool available from geomorphtools.org

Slope-arearelationships

sn

Normalized steepness throughout the channel network

links to process domains?

correlations to degradedor resilient reaches?

Ksn is directly related to erosion rate

DiBiase and Whipple, 2011But what can it tell us about geomorphic process domains and fish habitat?

sn

Normalized steepness throughout the channel network

sn

Normalized steepness throughout the channel network

Lidar data greatlyenhances our predictions of fine scale habitatand geomorphic process domains

Mostly Unconfined

Partially Confined

Confined

Lidar data capturessubtle, but criticalchanges in valley bottom morphology

Mostly Unconfined

Partially Confined

Confined

Valley confinementis a 1° control onhabitat type andvulnerability

Lidar is needed fordetailed mapping

Twitchell Canyon Summary1. Twitchell Canyon fire was a 1% event in spatial extent, with 1/3 burning at high severity

…important implications for management of native trout populations

2. Hillslope and stream network impacts have been highly variable…but predictable…transition points in normalized steepness correlate to erosion-deposition…valley bottom width and confinement are good predictors of habitat vulnerability

AcknowledgementsShannon BelmontWally MacFarlane, Josh Gilbert, Jordan Gilbert, Gary O’Brien, Joe Wheaton, Nick BouwesDan Bone, Evan Pool