# Presentation: 681747

## Fluxnet Canada: New Results and Contributions to the NACP

- Larry Flanagan, Carole Coursolle, Hank Margolis, Alan Barr, Brian Amiro, Andy Black, Jing Chen
- and the Fluxnet-Canada Science Community
- October 5, 2004

## Slide 2

## Outline

- National-scale carbon budget models
- Fluxnet-Canada measurements to validate and improve the national models
- New initiatives: Scaling Studies

## Canadian Carbon Budget Models

- Integrated Terrestrial Ecosystem C-budget model (InTEC: Chen, Cihlar, Liu, Chen)
- Carbon Budget Model-Canadian Forest Service (CBM-CFS2: Kurz and Apps)

## C Accounting Model

- Forest Inventory

- Volume to
- Biomass
- Conversion

- Volume / Age
-     Curves

-     CBM-CFS2

- Model parameters
-   Litterfall
-   Decomposition

- Harvesting
- Planting
- Disturbances

- National Carbon Budget

## Nitrogen

- Deposition

- Climate
- Variables

- Atmospheric
- Carbon dioxide

- Annual NPP

- Disturbances
-   Harvesting
-   Fire
-   Insects

- Soil C-N Cycles
- Century Model

- Biomass

- Available

- Photosynthesis
- Model + Upscaling

## InTEC Carbon Budget Model

##  C Budget Model Comparisons

- Model Calculations for Carbon Budget of Canadian Forests 1980–1996 (Tg C year-1)
- 	InTEC			50 		Sink
- 	CBM-CFS2		50-100	Source

## InTEC includes modeled response to:

- Atmospheric deposition of N
- Elevated atmospheric carbon dioxide
- Increased length of growing season
- Temperature stimulation of decomposition and nutrient release
- These modeled responses need to be tested with field observations

## Fluxnet-Canada New Results:

- Post-disturbance carbon budget studies
- Eco-physiological studies that provide insights to controls on ecosystem processes

## Fluxnet-Canada Carbon Flux Stations

- Coastal conifers

- Southern boreal conifers and hardwoods

- Boreal mixedwood

- Boreal black spruce

- Balsam fir

- Eastern peatland

- Western peatland

- Grassland

##         NEPMax, mol m-2 s-1

-         NEPMax, mol m-2 s-1

##        GEPMax, mol m-2 s-1

-        GEPMax, mol m-2 s-1

##         TERMax, mol m-2 s-1

-         TERMax, mol m-2 s-1

## Effects of Fire and Harvest:

- Fire
- 	- removes fine materials
- 	- leaves coarse materials
- Harvesting
- 	- removes coarse materials
- 	- leaves fine materials

## NEP (g C m-2 day-1)

- NEP (g C m-2 day-1)

- Sink - Positive
- Source - Negative

## Slide 18

## Slide 19

##                     NEP, g C m-2 yr-1                        

-                     **NEP, g C m****-2**** yr****-1                       **

**Sink**

**Source**

## Eco-physiological Studies

- Empirical information for validation of model assumptions and output
- Observations to detect climate change responses

## Slide 22

## Slide 23

## Variation in Water-use Efficiency      among Contrasting Ecosystems

- Contributions of environmental & biological components to variation in WUE
- Evergreen conifer: Douglas-fir
- Broad-leaf deciduous: Aspen
- Grass: Wheatgrass

## Slide 25

## Slide 26

|  | Douglas-fir | Aspen | Grassland |
| --- | --- | --- | --- |
| WUE
mmol mol-1 | 8.4 ± 1.7 | 5.1 ± 2.1 | 2.8 ± 0.6 |
| 13C
‰ | -25.9 | -25.3 | -25.1 |
| Ci/Ca | 0.59 | 0.57 | 0.56 |

## New Initiatives: Scaling Studies

- Proposals for equipping 2 new tall towers for precise CO2 concentration measurements - inverse modeling studies, mixed layer: free-tropospheric gradient studies
- Fluxnet-Canada involvement as collaborators on Remote Sensing studies recently funded by NASA-NACP program
- Planned inclusion of arctic tundra sites in proposal for phase2 of Fluxnet-Canada: 2007-2012