PermafrostHydrology

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Permafrost/Hydrology 2009 LTER Symposium Ted
Schuur University of Florida Merritt
Turetsky University of Guelph Jay
Jones University of Alaska
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State Factors
Humans
Climate
Time
Ecosystem Dynamics
Permafrost
Hydrology
Topography
Organisms
Parent material
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Presentation Overview

• What is the effect of changes in permafrost and
  hydrologic regime on terrestrial and aquatic
  ecosystem dynamics?
• 1. Upland Thermokarst
• (Schuur Eight Mile Lake/Healy)
• Wetlands
• (Turetsky APEX/Bonanza Creek Bluff)
• Upland Streams
• (Jones Caribou Poker Creek)

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Schuur, E.A.G., J. Bockheim, J. Canadell, E.
Euskirchen, C.B. Field, S.V Goryachkin, S.
Hagemann, P. Kuhry, P. Lafleur, H. Lee, G.
Mazhitova, F. E. Nelson, A. Rinke, V. Romanovsky,
N. Shiklomanov, C. Tarnocai, S. Venevsky, J. G.
Vogel, S.A. Zimov. 2008. Vulnerability of
permafrost carbon to climate change Implications
for the global carbon cycle. BioScience 58
701-714.
Effects on Ecosystems/Hydrology
Permafrost Thaw
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Global Carbon Pools
Global Vegetation C 650 Pg Global Soil C
(1m) 1500 Pg Atmosphere 777
Pg Permafrost Zone Soil C Peatlands (several
m) 277 Pg Mineral Soil (3m) 747
Pg Siberian Deep C (25m) 407 Pg Alluvial
Deep C (25m) 241 Pg 1672 Pg
Jobaggy et al. 2000, Field et al. 2007, Zimov et
al. 2006, Tarnocai, in press, Schuur et al. 2008
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The impact of permafrost thaw on old carbon
release and net exchange from tundra
Minimal neutral Moderate sink (?GPP,
?Reco) Extensive source (?GPP, ?Reco)
Minimal 66 g m-2 yr-1 Moderate
?40 Extensive ?78
Schuur et al. in press, Vogel et al., in press
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Permafrost Carbon Pool
Permafrost Zone Soil C Gelisol Soil Order
(3m) 818 Pg x 9.4-12.9 77-106
Pg Permafrost C Loss (0.8-1.1
Pg/yr) Current Land Use Change (1.50.5 Pg/yr)
Deep Permafrost C 650 Pg x ? ?
Pg
Schuur et al. in press
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Hydrologic Carbon Export
Annual Flux (g C m-2 yr-1)
Min Mod Ext DIC 1.9 0.9 1.6 DOC 6.7 7.0 9.6
GPP 320 419 435 Reco -336 -394 -467 DICDOC
-2.6 -1.6 -2.6 NEE -17 25 -32
Sickman et al. in prep
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Permafrost Warming Experiment
S. Natali, unpublished data
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Climate
Gradual Warming/snow depth
Extreme Events
Drought/Fire or Deluge/Flooding
Vegetation (composition, physiology)
Permafrost (hydroclimate, thaw depth, thermokarst)
Thermal Insulation, Storativity
Soil moisture, Redox
C structure and decomposability, Microclimate
Nutrients, ET
Soil Gaseous Phase CO2/CH4 fluxes
Soil Solid Phase C Storage, Accumulation
Soil Liquid Phase DOC, DON fluxes
Conductivity, Connectivity,Redox,
Redox, Ebullition, Efflux
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• Themes of current wetland research
• How do interactions between vegetation and thaw
  depth affect the rate and nature of soil organic
  matter formation?
• Soil hydroclimate controls (warming, drought,
  thermokarst) on vegetation, organic matter
  formation, and carbon/energy balance
• Approaches currently being used
• Experimental manipulation of water table and soil
  temperature (OTCs, snow depth)
• Gradient studies along ecotone from black spruce
  to open peatland
• Comparative studies across permafrost regimes
  (peatlands with intact permafrost, thermokarst,
  no permafrost)

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WetlandGradient/Ecotone
Black Spruce
Willow/Bog Birch
Tussock Grass
Emergent Marsh
Rich fen
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WetlandGradient/Ecotone
Black Spruce
Willow/Bog Birch
Tussock Grass
Emergent Marsh
Rich fen
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Hydroclimatemanipulations
Veg controls
GPP PAR, WT
Hydroclimate controls
ER WT, temp
CH4 WT, temp
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Hydroclimatemanipulations
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PERMAFROST, HYDROLOGY AND STREAM SOLUTES Task
I/S1 Monitoring patterns of retention and loss
of water, carbon and nitrogen from watersheds
with differing permafrost extent and stability
Climate
Fire (Frequency Intensity)
CO2/CH4
Permafrost (extent, thaw depth, thermokarst)
Vegetation (spruce vs. hardwoods moss)
Soil composition
Redox potential
Soil moisture/ groundwater flows
Stream hydrology and solutes
Fluvial exports
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PERMAFROST, HYDROLOGY AND STREAM SOLUTES

• Hydrograph separation using EMMA (PCA based
  approach)
• Four flowpaths Q1 from soils, Q2, Q3 Q4 from
  deeper source waters
• Soil water dominant source in the C3 stream, Q2
  dominant source in C2 and C4
• Coupled to patterns in hydrology, the high
  permafrost watershed has highest DOC, but lowest
  nitrate concentrations
• Lower nitrate in the high PF stream indicative
  that shallow soil not the source of DIN to streams

(from Jones et al., in prep)
(from Jones et al., 2005)
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FIRE AND STREAM SOLUTES

• Fire had a dramatic effect on stream solutes
• Stream nitrate concentration increased 130
  (SO4 and K also increased)
• Increase potentially due to reduced competition
  between vegetation and soil microbes
  (nitrification), or increase in active layer
  depth and flushing of deeper stores
• Stream DOC declined 22 (DON, DOCDON and Ca2
  also declined)
• Decline potentially due to combustion of soil
  carbon, transformation of soil carbon to less
  soluble compounds, or decline in soil carbon
  mineralization

(from Betts and Jones, in review)
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SOURCE WATER AND DOM QUALITY
DOM composition measured by fluorescence
excitation emission
DOM quality measured by one-month bioassays

• Axis 1 related to reduction-oxidation potential
  of DOM (oxidized/reduced quinone)
• Axis 2 related to DOM quality (tyrosine and
  tryptophan)
• DOM from thermokarsts of low quality, whereas
  springs flowing from shallow source waters
  enriched in labile DOM
• Within streams, DOM tends to be fairly
  recalcitrant. Labile DOM rapidly consumed near
  source

(from Balcarczyk et al., in review)
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