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
Understanding the role of hydrology in mediating the southern boreal forest s response to climate change 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? `
Boreal Ecozone Research and Monitoring Sites
Mature Sites (still in operation) 100 km Old Aspen (Deciduous) Old Black Spruce (Wet Coniferous) Old Jack Pine (Dry Coniferous) Fen (Wetland)
Strategy 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
Ecosystem Function
Annual Carbon Fluxes: NEP = GEP RE Old Aspen 1997-2017 (Jilmarie Stephens, UBC) drought defoliation Gross Ecosystem Photosynthesis Ecosystem Respiration Net Ecosystem Production
Forest Tent Caterpillar Outbreak at Old Aspen in 2016 as seen from Harvard PhenoCam 13 May 2016
13 May 2016 2 June 2016
13 May 2016 26 June 2016
Old Aspen 2016 Carbon & Water Fluxes Measured No Defoliation (reconstructed) GEP RE NEP ET
Annual Carbon Fluxes BERMS Forest Sites 1997-2017 (Andy Black, Warren Helgason) Aspen Black Spruce Jack Pine
Soil Temperature and Ecosystem Respiration BERMS Forest Sites 1997-2017 Aspen Black Spruce Jack Pine Year
Forest Carbon Dynamics, Dendrochronology (Colin Laroque, Jill Johnstone)
Changing Forest Stem Density and Tree Mortality, 1994-2016 (Colin Laroque, Jay Maillet) Pine Aspen
Comparing Cumulative Flux-Tower NEP With Measured C Stock Changes, 1994-2016 (Colin Laroque, Jay Maillet) ΔC Debris ΔC Dead Trees ΔC Live Trees Flux Tower Forest Floor? Pine Aspen
Tree Rings Analysis for Early Warning Signals of Tree Mortality (Steve Mamet, Jill Johnstone) Submesic Subhygric Subxeric
Correlation Coefficient Water Table Level as a Major Determinant of Tree Radial Growth, BERMS Fen (Magali Nehemy, Colin Laroque) 0.6 0.4 0.2 0.0-0.2-0.4-0.6-0.8 Apr May Jun Jul Aug Sep Oct Black Spruce Larch Centre Larch East
Wiley Interdisciplinary Reviews: Water 2: 505 521.
Hydrology
Stand-Level Water Balances By 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
Annual Stand-Level Outflow R in Relation to Soil Water Storage Normalized May-Sept Storage (mm)
Hydrograph, White Gull Creek 94 97 00 03 06 09 12 15
Model Evaluation
MESH Modelling of White Gull Creek Watershed (Bruce Davison, ECCC) Adding slope (lateral exchange) improved model performance But unable to capture extreme peak flows of 2011 Need to represent wetland storage
MESH Modelling Observed Modelled
40-100 10-40 0-10 cm NOAH-MP Modelling at BERMS Old Aspen Inclusion of a forest-floor soil organic layer (Liang Chen and Yanping Li) Annual Cycles of Soil Temperature NOAH-MP +Organic Observed
CTEM Modeling: Vegetation Dynamics at the Forest-Grassland Ecotone (Omer Yetemen, Andrew Ireson) Long-term mean CMI (CMI from Ted Hogg, CFS)
Snow Water Equivalent (mm) Snow Accumulation and Melt Evaluating SHAW, CRHM and CLASS Old Jack Pine (Faizan Ahmed, Amber Peterson) Observed SHAW CRHM CLASS 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)
Accomplishments: Observations 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: Process Understanding 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 uplandwetland lateral exchange; use of tree rings as proxy for water table depth
Accomplishments: Modelling 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
Ongoing and Emerging Questions: 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