Arctic Streams in a Changing Climate

The Streams Research GroupBreck Bowden, Coordinator

University of Vermont

Arc

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Arctic LTER Mid-Term Review18 June 2013

The Arctic LTER Streams Team• Breck Bowden, University of Vermont (lead-PI)• Linda Deegan, Ecosystems Center (co-PI)• Michael Flinn, Murray State University (co-PI)• Sarah Godsey, Idaho State University, (co-PI)• Michael Gooseff, Pennsylvania State University (co-PI)• Tamara Harms, University of Alaska-Fairbanks (co-PI)• Alex Huryn, University of Alabama (co-PI)• Bruce Peterson, Ecosystems Center (co-PI)• Will Wolheim, University of New Hampshire (co-PI)• Kyle Whittinghill, University of New Hampshire (Post-Doc)• Elissa Schuett, University of Vermont (Staff Technician)• Josh Benes, University of Vermont (Staff Technician)• Cameron MacKenzie, Ecosystem Center (Staff Technician)• Erica Betts, University of Alaska-Fairbanks (Ph.D. Student)• Heidi Golden, University of Connecticut (Ph.D. Student)• Michael Kendricks, University of Alabama (Ph.D. Student)• Julia Larouche, University of Vermont, Ph.D. Student• Sam Parker, University of Vermont (Ph.D. Student)• Jeff Kampman, Murray State University (M.S. Student)• Adam Wloskowski, University of Vermont (M.S. Student)• …and numerous REU, graduate, and co-PI alumni

Streams interpretation of the overall ArcLTER goal

What we proposed:

• Long-term monitoring

• Effects of long-term fertilization

• Hydrologic disruption of stream food webs

• Stream structure and habitat quality in a changing arctic landscape

What we hypothesized: “Our overarching hypothesis is that arctic headwater streams are poised to undergo – and may have already begun – a phase of adjustment to climate warming that will substantially alter the hydrologic, nutrient, and sediment regimes in stream ecosystems in ways that will significantly change their biotic structure and ecological functions.”

Mapping ArcLTER Objectives to Streams Research

Take home messages about the Streams research (This talk)

• Foundations– The disturbance template– Bottom up and top down effects– The hyporheic influence

• Current research– Arctic stream biogeochemistry in a

changing climate– Arctic stream ecology in a changing

climate

• Synthesis and integration

ArcLTER Shared Objectives

1. How does climate control ecosystem states, processes, and linkages?

2. How do disturbances change ecosystem states, processes, and linkages?

3. How do climate and disturbance interact to control biogeochemical cycles and biodiversity at catchment and landscape scales?

Where we’ve worked

Toolik Field Station GIS Map Archive

Tundra

Beaded

Mountain

Glacial Aufeis

Spring

Foundation: Arctic Stream Types

Bowden et al. (2013) ArcLTER Synthesis

Characteristics of Arctic Streams• High inter- and intra-annual variability in discharge

• In general, oligotrophic and unproductive, but…

• Specific stream types do differ

• Fewer food web components, but…

• Reasonably complicated food web interactions

Kuparuk River, Parker (2008) Thymallus arcticus , M. Kendricks

Take Home Message:A Habitat Template for North Slope Streams

Parker and Huryn (2011)

• Major driver: substrate disturbance from variable discharge events

• Major driver: freezing conditions (tipping point for freezing during winter)

• Minor driver: oligotrophic conditions

Discharge and freezing are “climate-susceptible” drivers

Foundation: Nutrients are not unimportant

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

PO4

Conc

entr

ation

(uM

)

Station

Kuparuk PO4 2010

6/21/2010 Q = 0.73 m3/s

7/14/2010 Q = 0.57 m3/s

8/16/2010 Q = 2.67 m3/s

PO4 dripper

Simple Phosphorus “Dripper” Experiment

The Kuparuk River Long-Term Fertilization

Experiment

1983-862011 - ?

1986-96

1996 - ?

Reference

Fertilized

Dalton Highway

Pipeli

ne

Flow

1983 to present

Our 30th year coming up!

The benefitsof LTERmonitoring

Updated from Slavik et al. (2004)

Kuparuk River

Long-term low-level fertilization with P has significantly altered the Kuparuk ecosystem

Reference reach substrate

Fertilized reach substrate

log[Post-moss:Pre-moss]

-1 0 1 2

% cover Micro-epilithon

% cover Bryophytes

Micro-Epilithic Chlorophyll

Black Fly

Baetis

Ephemerella

Brachycentrus

Chironomid

Orthocladius

Age - 0 Grayling

Adult Grayling

FertilizedReference

Summary of Bryophyte Effects on Stream Ecosystems

Slavik et al. 2004

2x5x

Take Home Message

Bottom-upand

Top-downInfluences on

Stream Ecosystems

FISH

INSECTCOMMUNITYSTRUCTURE

EPILITHON

PERIPHYTON

BRYOPHYTES

NUTRIENTS

DETRITUSCPOM/FPOM/DOM

?drift

-shade-abrasion

+space

-smother ?N fix

-C:N+temperature

?shredders+scrapers-filter feeders

+high quality -low quality

+slough+scour

-competition

+feces

+feces

-grazing

+scapers+filter feeders

+P, +N+ToC+light

+scour

+P, +N+ToC+light

BENTHOS BENTHOS

+fragmentationStream Bryophyte Group (1999)

From Runkel (1998)

‘Hyporheic’Lateral eddies

Foundation: Transient Storage Dynamics in Arctic Streams

Why is the hyporheic zone of interest?

• In some places, unique organisms live there

• Considerable biogeochemical cycling goes on in the hyporheic zone – gravel filter

• There is good reason to think that climate warming could change the nature of hyporheic processing in permafrost-dominated streams

Primary Question

As the extent of the active-layer increases through a thaw season, does the physical extent of the HZ also increase?

Early SummerSpring Late Summer

Permafrost

HZHZ

Permafrost

HZ HZ

Take Home Message: Only a portion of the thaw bulb is hyporheic

Aal

Permafrost

Ahz

0.00

0.20

0.40

0.60

0.80

1.00

0 50 100 150 200

Active-layer Scenario

Ah

z :

Aal

8I

PI

Ah

z :

Aal

• Rate of change for both sites decreases as they approach 200%• 8I alluvial HZ exchanges across more of the active-layer• Morphology important to HZ exchange utilization of potential area

Alluvial

Peat

Zarnetske et al. (2008)

Changing Seasonality rather than Warming per se, is the Key Driver

Seasonality of temperature is changing…

Kittel et al. (2011)

…seasonality of vegetation green-ness, less so.

Walker et al. (2011Arctic Report Card)

Current Research:Seasonal Asynchrony in microbial

production and plant demand

Vegetation(and snow)

Soil

Stream

Spr

ing

bypa

ss

Vegetation

Soil

Stream

Vegetation(and snow)

Soil

Stream

Vegetation

Soil

Stream

Spring Summer Autumn

Nitrate concentrations increase in the fall

G Waldvogel and WB Bowden, unpublished data

PlantBiomass

Organic

Mineral

Open Channel

Hyporheic

VegetationCommunity

RiparianSoils

Stream Network

H1: NetUptake

H2: AlteredFlowpaths

H3: In-Stream Processing

Take Home Message:There are multiple Influences of

changing seasonality on stream biogeochemistry

Tim

e/T

haw

Dep

th NutrientExport

Senescence

Mineralization

Mineralization

Current Research - FISHSCAPES:Seasonality and synchrony of ecological

processes in arctic streams

- Earlier spring melt- Later fall freeze up- Less rain late season- Increased stream temperatures

PIT tagging grayling adults (>25cm)

PIT tag antenna installation

Imagery © Earthstar Geographics

Kuparuk RiverDalton HighwayAlaska Pipeline

Survival depends on a fall migration to a “safe” lake

Fall migration to headwater lakes

Image credits: C. MacKenzie

Photo credit: A. Huryn

Photo credit:W. Bowden

When and where “dry reaches” occur is critical

Kuparuk River – Pool of grayling trapped in main-stem below dry

channel (≈1000 adults)

Photo credit: C. Mackenzie

Historical periods of hydrological discontinuity in the Kuparuk River

1-Jun8-Jun

15-Jun22-Jun

29-Jun6-Jul

13-Jul20-Jul

27-Jul3-Aug

10-Aug

17-Aug

24-Aug

31-Aug7-Sep

14-Sep1995

1997

1999

2001

2003

2005

2007

2009

2011

2013

Typical Grayling Migration period

Fish could not reach the lake and crowded in the river in 2011

Freq

uenc

y0

2040

6080

100

08/04/10 08/12/10 08/20/10 08/29/10 09/06/10 09/15/10

Freq

uenc

y0

2040

6080

100

08/04/11 08/12/11 08/20/11 08/29/11 09/06/11 09/15/11

Fre

qu

ency

of

mig

ran

ts e

nte

rin

g la

ke 2010 2011

08/04 09/14 08/04 09/1408/15 08/15

C. MacKenzie, L. Deegan, and B. Peterson, unpublished data.

Crowding, competition and lack of food impeded fish growth

Gained mass in June and July during good flow and then lost mass during September low flow period and isolation in pools.

Mid Early

2011

C. MacKenzie, L. Deegan, and B. Peterson, unpublished data.

Leave Lake Earlier

Return To Lake Later

Lower Lake Trout Growth and Population Size

Earlier Lake Thaw

Less Fall Rain and Late Freeze Up

Late Season Droughts

Take Home Message:Climate impacts on hydrology may make

rivers less hospitable for some fish

Create a Fragmented Landscape

Less time in lake

Poorer Condition

Arctic G

rayling

Clim

ate

driv

ers

and

e

nvir

onm

enta

l re

spo

nse

s

Heidi Golden Mark UrbanUniversity of Connecticut

What does the loss of a migratory population mean to the function of lakes and streams in the landscape?

Exciting, breaking news!Fish under spring ice

Courtesy of Heidi Golden and Cam MacKenzie

Possible winter liquid water overflow locations

Mapping ArcLTER Objectives to Streams Research

Take home messages about the Streams research (This talk)

• Physical factors (freezing, Q) define key habitats.

• Top down effects are more subtle than bottom up.

• Hyporheic duration is more important that hyporheic extent.

• Changing seasonality is creating important biogeochemical asynchronies

• Changing seasonality may threaten the survival of important fish species in these streams.

• The ArcLTER provides a critical base for a diverse program of Streams research.

ArcLTER Shared Objectives

1. How does climate control ecosystem states, processes, and linkages?

2. How do disturbances change ecosystem states, processes, and linkages?

3. How do climate and disturbance interact to control biogeochemical cycles and biodiversity at catchment and landscape scales?

Thank you!