boreal ecosystem research and monitoring sites · 2018. 3. 12. · progress and prospects at the...
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Progress and Prospects at the Boreal Ecosystem Research and Monitoring Sites
Alan Barr, Warren Helgason, Andy Black, Andrew Ireson, Colin Laroque, Jill Johnstone,
Garth van der Kamp, Bruce Davison
Faizan Ahmed, Jilmarie Stephens, Jason Maillet, Magali Nehemy, Mahtab Nazarbakhsh,
Amber Peterson, Bruce Johnson
• How can we use the observed responses to inter-annual climate variability at flux towers to inform the most likely responses to climate change?
• How can we improve models to better link hydrology, ecosystem productivity and vegetation dynamics?
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Understanding the role of hydrology in mediating the southern boreal forest’s
response to climate change
Boreal Ecozone Research and Monitoring Sites
Old Aspen(Deciduous)
Old Black Spruce(Wet Coniferous)
Old Jack Pine(Dry Coniferous)
100 km
Fen(Wetland)
Mature Sites (still in operation)
Core, long-term observations of the carbon, water and energy balances, anchoring: • process studies of ecosystem function • evaluation and improvement of
hydrological and land-surface-process models
• remote sensing studies
Strategy
Ecosystem Function
Annual Carbon Fluxes: NEP = GEP – REOld Aspen 1997-2017 (Jilmarie Stephens, UBC)
drought defoliation
Gross Ecosystem
PhotosynthesisEcosystem Respiration
Net Ecosystem Production
13 May 2016
Forest Tent Caterpillar Outbreak at Old Aspen in 2016as seen from Harvard PhenoCam
2 June 2016
13 May 2016
13 May 2016
26 June 2016
Old Aspen 2016 Carbon & Water Fluxes
GEP RE
NEP ET
Measured No Defoliation (reconstructed)
Aspen Black Spruce Jack Pine
Annual Carbon FluxesBERMS Forest Sites 1997-2017
(Andy Black, Warren Helgason)
Aspen Black Spruce Jack Pine
Soil Temperature and Ecosystem RespirationBERMS Forest Sites 1997-2017
Year
Forest Carbon Dynamics, Dendrochronology(Colin Laroque, Jill Johnstone)
Pine Aspen
Changing Forest Stem Density and Tree Mortality, 1994-2016
(Colin Laroque, Jay Maillet)
ΔC DebrisΔC Dead TreesΔC Live Trees
Flux Tower
Pine Aspen
ForestFloor?
Comparing Cumulative Flux-Tower NEPWith Measured C Stock Changes, 1994-2016
(Colin Laroque, Jay Maillet)
Tree Rings Analysis for Early Warning Signals of Tree Mortality
(Steve Mamet, Jill Johnstone)
SubhygricSubxeric
Submesic
Water Table Level as a Major Determinantof Tree Radial Growth, BERMS Fen
(Magali Nehemy, Colin Laroque)
BlackSpruce
Larch CentreLarchEast
0.6
0.4
0.2
0.0-0.2
-0.4
-0.6
-0.8
Apr May Jun Jul Aug Sep Oct
Co
rrel
atio
n C
oef
fici
ent
Wiley Interdisciplinary Reviews: Water 2: 505–521.
Hydrology
Stand-Level Water BalancesBy Vegetation Type
(Alan Barr, Garth van der Kamp)
Aspen Spruce Pine Harvested Fen Streamflow
Annual Streamflow in Relation to Precipitation, White Gull Creek
Hydrologic Years (Oct-Sept, 1997-98 to 2014-15)
2010-11: High P, wet landscape
2003-04: High P, rewetting landscape
Normalized May-Sept Storage (mm)
Annual Stand-Level Outflow Rin Relation to Soil Water Storage
‘94 ‘97 ‘00 ‘03 ‘06 ‘09 ‘12 ‘15
Hydrograph, White Gull Creek
Model Evaluation
Adding slope (lateral exchange) improved model performance
But unable to capture extreme peak flows of 2011
Need to represent wetland storage
MESH Modelling of White Gull Creek Watershed
(Bruce Davison, ECCC)
MESH Modelling
Observed Modelled
NOAH-MP Modelling at BERMS Old AspenInclusion of a forest-floor soil organic layer
(Liang Chen and Yanping Li)
Annual Cycles of Soil Temperature
NOAH-MP +OrganicObserved
40
-10
0
10
-40
0
-10
cm
CTEM Modeling: Vegetation Dynamics at the Forest-Grassland Ecotone
(Omer Yetemen, Andrew Ireson)
Long-term
mean CMI
(CMI from Ted Hogg, CFS)
ObservedSHAWCRHMCLASS
Sno
w W
ate
r E
quiv
ale
nt
(mm
)Snow Accumulation and Melt
Evaluating SHAW, CRHM and CLASSOld Jack Pine (Faizan Ahmed, Amber Peterson)
Oct Nov Dec Jan Feb Mar Apr May Jun
Links to Remote Sensing
Monitoring Freeze/Thaw Cycles L-Band Radiometers for SMAP Satellite Mission
(Alexandre Roy, U. Montreal, Chris Derksen ECCC)
Comparing start day of photosynthesis from flux towers with snow clearance day
from microwave remote sensing (Pulliainen, Finnish Met Institute)
Photosynthetic Efficiency (LUE) of Northern Forests
from MODIS Photochemical Reflectance Index (PRI) (EM Middleton, NASA Goddard)
• 20+ years of CWE (carbon, water and energy) flux measurements above aspen, spruce, pine and fen
• Finally! a severe insect defoliation event
• Enhanced focus on snow melt and spring thaw
• Value-added observations of freeze-thaw processes, tree water relations, sapflow, and dendrochronology
• Widespread use of the data in multi-site syntheses and as ground-truth in remote sensing
Accomplishments: Observations
• Characterization of the large variations in evapotranspiration and outflow across the boreal forest mosaic
• Enhanced understanding of inter-annual variability, including aspen defoliation and recovery; emerging trends?
• Importance of wetland storage and upland-wetland lateral exchange; use of tree rings as proxy for water table depth
Accomplishments: Process Understanding
• Importance of lateral exchange processes in the boreal forest upland-lowland-wetland mosaic
• Progress in linking water stress to vegetation dynamics in CLASS-CTEM
• Importance of forest-floor organic soil horizons
• Evaluation of SHAW, CHRM, and CLASS -- snow accumulation, snow melt and soil thaw; model differences in timing of spring melt and thaw related to differences in structure
Accomplishments: Modelling
• Role of hydrology in mediating the boreal forest’s response to climate change
• Snowmelt and soil thaw processes
• Influence of plant phenological phases and seasonal precipitation inputs on the forest’s sources of water
• Forest management under a changing climate
Ongoing and Emerging Questions: