To: Steve Wofsy, NACP Chair, Harvard University (USA)

From:Hank Margolis, Fluxnet-Canada Science Program Leader, Université Laval

Subject:Links Between Fluxnet-Canada and the North American Carbon Program (NACP)

Date:September 26, 2001

The members of the Fluxnet-Canada Research Network have now had the opportunity to examine the draft plan of the North American Carbon Program (NACP). As the Science Program Leader for Fluxnet-Canada, it has been my task to consolidate our collective comments into the current document. I will begin by briefly explaining Fluxnet-Canada and then address some of our thoughts about the potential relationship between our network and the NACP.

Background on Fluxnet-Canada

Fluxnet-Canada has recently requested funding as a Canadian university research network from a number of different funding sources in Canada. These include primarily NSERC, Canadian Foundation for Climate and Atmospheric Sciences (CFCAS), the Canada Foundation for Innovation (CFI), and the BIOCAP-Canada Foundation. Very significant support will also be provided from our partners in the federal government, provincial research institutes, and forest industry. A funding decision should be announced by early November and we are optimistic and hopeful that our proposed research network will soon become a reality.

Fluxnet-Canada has four principal objectives:

  1. Make tower-based eddy covariance measurements of the exchanges of CO2, sensible heat, and water, and in some cases other greenhouse gases, for mature and disturbed forest and peatland ecosystems along an east-west national transect that encompasses many of Canada’s important southern ecoregions. We will (a) examine the relationship between the inter-annual variability of carbon fluxes and climate, (b) analyze the contribution of different ecosystem components to the net flux; (c) explore the relationship between net primary productivity and net ecosystem exchange, and (d) parameterize and evaluate ecosystem and land surface climate models. This information will be used to extrapolate the knowledge obtained from the specific flux measurement sites in both space and time.
  2. Evaluate the simple relationships between climate variables (e.g., mean monthly temperature) and net ecosystem exchange on both the disturbed and undisturbed sites.
  3. Evaluate the relationship between the multi-year measurements of net ecosystem exchange from the towers with multi-year changes in carbon stocks measured by forest inventory and other biometric techniques.
  4. Use the knowledge gained in attaining the above objectives, combined with existing land cover data, to provide better first-order approximations of the total potential for carbon uptake, emission and sequestration by Canadian forests and wetlands on regional and national scales.

A combination of measurements and modelling has been proposed for six Canadian-run flux stations located along an east-west forest transect in British Columbia, Alberta, Saskatchewan, Ontario, Quebec and New Brunswick and at a peatland station with sites in eastern Ontario and western Quebec. At each station, we hope that one or more eddy covariance towers in undisturbed ecosystems will be combined with at least one other tower that will study the environmental controls on carbon fluxes from disturbed ecosystems, i.e., following fire, logging, or commercial thinning. Network activities include maintaining and reinforcing research at existing stations as well as establishing a number of new stations so that a national transect can be established. The effects of disturbance will be studied using a hierarchical measurement approach whereby a complementary strategy of different intensities of flux measurements will occur across the network, ranging from long-term, continuous measurements to several-week long campaigns during the peak of the growing season. Calibration of flux measurements between stations will be accomplished by a roving standard set of equipment that will visit all our permanent flux sites at least twice over the study. We also see the flux sites that you and Mike Goulden are operating in Manitoba as a part of the overall science effort of Fluxnet-Canada, although administratively we treat it as an “associated station” since your support comes from the US. While there are some important differences, Fluxnet-Canada in many ways can be thought of as a Canadian version of the Ameriflux effort with which you are already familiar. Fluxnet-Canada is designed to provide some of the fundamental scientific information necessary for Canada to use its biosphere to help meet its international commitments to reduce greenhouse gas emissions.

Potential Relationship Between Fluxnet-Canada and the NACP

The stated goals of the NACP are (a) to develop scientific knowledge of the current state of the climate system and the scientific and technical tools to enable forecasts of future increases in concentrations of atmospheric CO2 and CH4 and (b) to provide the scientific information needed to design policies to reduce net emissions of CO2 and CH4 to the atmosphere from the US and neighbouring countries. We believe that the NACP could provide an excellent opportunity for Canada to advance its own carbon cycle measurement and modelling projects and hence to support the objectives of both Fluxnet-Canada and Canadian carbon cycle research in general. The objectives of the NACP are in line with Canadian perspectives and plans. They should result in major scientific advances and, if organized properly, should be of mutual benefit to both Canada and the USA.

We are very impressed by the large size and scope of the NACP. We are particularly pleased to see the planned integration of the different approaches used to study thecarbon cycle and the close coordination from the various US agencies that will be involved. Linking a range of carbon models to a combination of satellite, aircraft, tall tower, flux tower, atmospheric flask sampling, and inventory data is the type of bold endeavour that is necessary to develop the scientific foundations for managing the carbon cycle in the 21st century. The efforts that are planned for developing the tools and concepts for regional carbon cycle analyses is of keen interest to Fluxnet-Canada participants. As well, we are intrigued by the proposed “data fusion” approach for carbon cycle studies that would be analogous to that used in numerical weather prediction.

Fluxnet-Canada brings together the principal scientists working on the carbon cycle of Canadian forests and peatlands. As you know, Fluxnet-Canada is comprised of a very talented and motivated group of scientists. We are hopeful that significant financial resources will soon be allocated to our efforts by Canadian funding sources. Nevertheless, Canada has a very large land area relative to the size of its population. Thus, coordinating our efforts with those of the NACP provides us with a potentially valuable leveraging opportunity to advance our overall understanding of carbon cycling in Canada.

Fluxnet-Canada’s potential contributions to the NACP include:

Provide information on ecosystem fluxes, annual carbon budgets, carbon stocks, and related information for a range of undisturbed Canadian forest and peatland ecosystems.

Provide similar information for disturbed ecosystems, particularly the effects of harvest, silvicultural treatment and fires.

Develop and test different ecosystem process models (ECOSYS, IBIS, InTEC, PCARS,
C-CLASS) so that they can incorporate the effects of climate and disturbance on carbon cycling in Canadian forests and peatlands.

Within the context of Fluxnet-Canada’s data policy, make our data available to the international scientific community.

Thus, Fluxnet-Canada takes a “bottom-up” approach whereby long-term, continuous measurements of specific ecosystems are combined with modelling and scaling to address large-scale carbon cycle issues. We intend to fully integrate our scientific activities with the Ameriflux ecosystem flux network. As well, a particularly intriguing aspect of the NACP for Fluxnet-Canada is the possibility of collaborating with various NACP scientists working on “top-down” approaches. This could result in significant value-added science for Fluxnet-Canada. Overall, we see Fluxnet-Canada as a strategic and essential step in the development of the NACP.

We also have the following specific suggestions regarding the NACP draft plan.

  1. We believe that it is very important to have representation from Fluxnet-Canada on the NACP sub-committees (e.g., the Science Steering Committee and the Interagency Working Group). We also encourage you to invite other representatives from the carbon cycling community in Canada to participate.
  2. We suggest that the text be modified so that the multi-lateral nature of the effort is clear. For example, consider the following quotes from the plan: (a) “designing carbon management strategies for the US” (page 4); (b) “strengthening the Nation’s network for continental and global atmospheric sampling” (page 7); (c) “expand and strengthen the Nation’s network of studies to measure CO2 and CH4 exchange” (page 8). While we expect that this kind of language is useful with US agencies, it detracts significantly from the desired multi-lateral aspects of the plan.
  3. The carbon cycle is intimately linked to the nitrogen and water cycles, but these aspects receive little to no attention in the current plan. We suggest that these links be strengthened. The importance of measuring nitrogen inputs, water use, and water constraints to C exchange should be considered as well as the need for gridded data on soil hydrologic properties.
  4. Vast areas of North America are comprised of tundra, taiga and other types of wetlands. These seem to have been largely neglected in the current plan and this needs to be corrected. Unfortunately, because of financial and human resource constraints, these types of ecosystems are outside of the current scope of Fluxnet-Canada.

We look forward to working with you and your NACP colleagues.

Sincerely,

Hank Margolis

Fluxnet-Canada Science Program Leader

Professor, Université Laval