Potential Pathways of Ecosystem Responses to Climate Change

Landsat MSS Image Mosaic1977-1986

USGS

Torre JorgensonABR, Inc.

Types of Land Change• Geomorphic processes

– Coastal (increased erosion, flooding, salt kill) – Fluvial (changed channel migration rates, sedimentation– Lacustrine (mid-summer drying, bank erosion, tapping, paludification)– Permafrost (ice-wedge degradation, slower permafrost formation)

• Hydrology– Earlier snowmelt and spring discharge– Higher spring water levels– Mid-summer lake drying (faster drawdown)– Lower mid-summer river discharge, active channel shrinkage– Decreased glacier meltwater input – Lake tapping and drainage

• Vegetation– Longer growing season (more biomass)– Earlier forage quality curve– Shrub expansion (height and infilling), (migration)– Succession after disturbance– Migration (alder, spruce, sphagnum)(corridors)– Microsite moisture shifts (wetter troughs, drier centers)– Leaching and acidification– Paludification (bog meadows, productivity decrease)– Species composition-community shifts

Approaches to Predicting Change

• Extrapolate from past changes– Soil/sediment stratigraphy, remote

sensing, historical photos

• Complex modeling

• Comparative ecosystem analysis– North Slope versus Seward Peninsula

Ecosystems of Northern Alaska

Coastal Pathways

Nearshore Water

Higher Tundra Deltas, Basins, Lagoons, Barrier Islands

Coastal Wet Sedge Tundra (brackish)

Coastal Wet Sedge Tundra (saline)

Coastal Grass Tundra

Coastal Dwarf Shrub (willow)

Coastal Barrens (including salt-killed tundra)

Upland Tussock Tundra

Lowland Moist Sedge-Shrub Tundra

Lowland Wet Sedge Tundra

Lowland Wet Sedge Tundra (swales)

Lowland Moist Sedge-Shrub Tundra

flooding, salinization

bank erosion

bank erosion

sedimentationmudsand

sedimentationsedimentation

sedimentation, less floodingsedimentation, less flooding

Mudflat C. subspath. D. fisheri

Coastal Meadow Toposequence

Lake Basin EvolutionIce-rich Center

Ice-rich Margin

Erosion of Ice-rich Center

Lacustrine Wet Sedge Tundra

Lowland Moist Sedge-Shrub Tundra

Lacustrine Barrens

Lacustrine Low Willow Scrub

Deep Lakes

Lacustrine Grass Marsh

Non-basinsBasins

Upland Tussock Tundra

Upland Tussock Tundra

Lowland Moist Sedge-Shrub Tundra

Shallow Lakes, Pits

Lowland Wet Sedge Tundra

Lowland Wet Sedge Tundra (swales)

complete drainagepartial drainage

Lacustrine Sedge Marsh

Lacustrine Grass Meadows

Lowland Bog Meadows

Lowland Low Birch-Willow Shrub

Upland Shrubby Tussock Tundra

successionsuccessionsuccession

paludification

paludification, acidification

paludification, acidification

bank erosion, thermokarstbank erosion, thermokarst

ice aggradation, paludification

shrub expansionshrub expansion

shrub expansion

paludification, acidification

paludification, acidification

paludification, acidification

paludification

thermokarst troughs and pits

Coastal Plain Pathways

ice aggradation, paludification

drying

Lowland Moist Sedge-Shrub Tundra:

Lowland Wet Sedge Tundra Conversion by lowering water table

Wet Sedge - NPRA

Bog Meadow – Seward Peninsula

Intermediate Degradation

Dead Tussocks

Advanced Degradation

Initial Stabilization

Infilling with Sphagnum

Drying After Permafrost Degradation

Photo by Torre Jorgenson

Lacustrine

Ecosystems

Lower Noatak Lowlands

Lacustrine Marsh: In deeper water (30–100 cm), Arctophila fulva

In shallower (<30 cm) water, Carex aquatilis, Eriophorum angustifolium and Utricularia vulgaris

Lowland Water: Shallow (<1.5 m) ponds: water freezes to the bottom during winter, thaws by early to mid-June, and is warmer than water in deep lakes.

Deep (1.5 m) lakes: water does not freeze to the bottom during winter in deeper portions of the lake.

Thermokarst Lake, Koyukuk Flats

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Riverine Barrens

Riverine Wet Sedge Tundra

Riverine Low Willow Scrub

Riverine Moist Tall

Willow Shrub

Riverine Dryas Dwarf Shrub

Lowland Wet Sedge

Tundra

Lowland Moist Sedge-Shrub

Tundra

Riverine Lake

Riverine Grass Marsh

Riverine Moist Sedge-Shrub

Tundra

Fluvial ProcessesM

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reduced flooding, frequent sedimentation, increased drainage

channel abandonment

reduced flooding,

less sedimentation,

increased drainage

paludi-fication

reduced flooding,

less sedimentation,

ice aggradation,

decreased drainage

sedimentation, paludification

ice aggradation,

less sedimentation

paludification

thermokarst, bank erosion

thermokarst

cutbank, increased drainage

channel migration

riverbank erosion

increased drainage

Lower Perennial River

Upland Dryas Dwarf Shrub

Upland Dry Tall Willow

Shrub Eol

ian

Sand

Dep

osit

Eolian Processes

Riverine Tall Alder-

Willow Shrub

Lowland Bog Meadow

Riverine Cottonwood

Forest

Riverine White Spruce

Forest

Upland Cassiope

Dwarf Shrub

paludification, acidification

drainage sedimentation,

alder expansion,

reduced flooding, less sedimentation, ice aggradation, decreased drainage

ice aggradation,

reduced sedimentation

paludificationUpland Low-

Birch-Willow Shrub

Upland Crowberry

Dwarf Shrub

Riverine Pathways

Lower Perennial River

Riverine Barrens

Riverine Moist Tall

Willow Shrub

Riverine Moist Low Willow Shrub

Upland Dry Dryas Dwarf Shrub

Riverine Wet Sedge Meadow

Lowland Wet Sedge Meadow

Water

Riverine Succession

Floodplains as Migration Corridors

Upland Hydrology:8-10 ka (loess) to 60 Ma surfacesHighly integrated drainagesSuprapermafrost Groundwater FlowSoil highly leached

Water-tracks

Upland Ecosystems

Swales/ Watertracks/ Troughs/ Basins

Mid-SlopesRidges

Upland Tussock Tundra

Lowland Birch-Willow Shrub

Deep Thaw Lakes

Upland Shrubby Tussock Tundra

Wet Sedge Meadow

Upland Alder Tall Shrub

Upland Dryas Dwarf Shrub

Tundra (including ericaceous dwarf shrub, cassiope

dwarf shrub)

Lowland Bog

Meadows

Upland Moist Sedge-Shrub

Tundra

Upland Low Birch-Willow Shrub

See Coastal Plain Basin Pathways

extremely ice-rich

thermokarst troughs and pits

Upland Alder Tall Shrub (including alder-tussock)

thaw slumps

Upland Pathways

acidificationshrub growth

acidificationshrub growth

alder expansion

alder expansion

ice aggradation,paludification

paludification

Noatak Basin Thaw SlumpsIce-rich Colluvium

Alkaline Toposequence

Upland Low Birch-Willow

Shrub Tundra:

NPRA

Seward Peninsula

King Salmon

High resilience of tussock tundra

MAAT = -12 C

MAAT = -6 C

MAAT = +2 C

Lichen Loss – Noatak Basin

1909 – Phillip Smith

2006 Photo by Torre Jorgenson

Shrub Expansion

Upland Tall Alder Shrub

Alnus crispa, Salix pulchra, Salix glauca, Vaccinium uliginosum, Vaccinium vitis-idaea, B. glandulosa, Ledum groenlandicum, Empetrum nigrum, Equisetum arvense, Spiraea beauverdiana, Calamagrostis canadensis, Petasites frigidus, Sphagnum spp., Hylocomium splendens

1918Near Naknek River, King Salmon

P. Hagelbarger

2005G. Frost

1918Near Naknek River, King Salmon

P. Hagelbarger

Fire

Disturbance

Ecosystems of Northern Alaska

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Potential Habitat Use by Threatenedor Endangered Species

Spatial modelling based on the mapping of ecosystems of Northern Alaska by ABR and TNC.Projection: Albers Equal-Area Conic (Central Meridian: -154°, Reference Latitude: 50°,Standard Parallel 1: 68°31', Standard Parallel 2: 70°54'); Datum: NAD 27ABR file: NoAk_TES_Hab_Use_02-161.mxd, 19 May 2003

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Kotzebue Sound

Approximate Scale = 1:4,600,000

25 0 25 50 75 100Miles

25 0 25 50 75 100 125Kilometers 5

CapeLisburne

Pt. Barrow

PrudhoeBay

DemarcationPoint

HABITAT USE BY THREATENED OR ENDANGERED SPECIES:The map links the evaluation of habitat use by two threatenedspecies (Spectacled and Steller’s eiders) to the map of 36 ecotypes(habitats). The map displays the distribution of habitats that areimportant to these threatened species. The index was computedas the highest use rank (0–3) for either species in each habitat.Actual distributions are much less than modeled distributions.

B e a u f o r t S e a

Documented breeding ranges based onLarned et al. (2003) for Spectacled Eidersand on Ritchie and King (2003) for Steller'sEiders. Total range poorly known.

Habitat Use

None (0)

Low (1)

Moderate (2)

High (3)

Documented breedingrange for Spectacled Eiders

Recent extent of Steller'sEider Observations

Circumpolar Arctic Vegetation Map

Walker et al. 2003