1. III. Bartlett Experimental Forest: Scaling field and flux measurements using a tiered remote sensing approach A New Research Program to Monitor Carbon Stocks and Fluxes at the Bartlett Experimental Forest, NH I. North American Carbon Program (NACP): Overview Andrew Richardson Scott Ollinger andrew.richardson@unh.eduandrew.richardson@unh.edu scott.ollinger@unh.edu scott.ollinger@unh.edu andrew.richardson@unh.eduscott.ollinger@unh.edu Complex Systems Research Center, University of New Hampshire, Durham, NH 03824 Marie-Louise Smith David Hollinger marielouisesmith@fs.fed.usmarielouisesmith@fs.fed.us dhollinger@fs.fed.us dhollinger@fs.fed.us marielouisesmith@fs.fed.usdhollinger@fs.fed.us USDA Forest Service, Northeastern Research Station, Durham, NH 03824 II. Norh American Carbon Program: Forest Land Measurements A U.S. interagency plan for carbon cycle research focused on measuring and understanding sources and sinks of CO2, CH4, and CO in North America and adjacent oceans (http://www.esig.ucar.edu/nacp/).http://www.esig.ucar.edu/nacp/ The central goal is to provide the scientific information needed to inform policies designed to reduce contributions by the United States and neighboring countries to atmospheric CO2 and CH4. The program will provide scientific data and analysis to determine the fate of CO2 emitted to the atmosphere by combustion of fossil fuels. It is also aimed at comprehensive understanding of the rates and mechanisms controlling carbon uptake and release from soils and vegetation in North America and the adjacent Atlantic and Pacific Oceans. NACP Program Elements Atmospheric measurements Land & ocean measurements Modeling to assimilate & synthesize Land measurements make a significant contribution to the science questions of the NACP  What is the carbon balance of North America and adjacent ocean basins, and how is the balance changing over time?  What are the sources and sinks, and the geographic patterns of carbon fluxes?  What factors control the sources and sinks, and how do they change with time?  Are there potential “surprises”, where sources could increase or sinks disappear?  How can we enhance and manage long-lived carbon sinks to sequester carbon? The forest land inventory component of the NACP involves development of a hierarchical, multi-tier monitoring approach that integrates the ongoing inventory and monitoring programs with intensive-site monitoring and process studies. A new monitoring tier (Tier 2) is proposed that will link extensive monitoring with the intensive flux and process study sites. Tier 2 will include clusters of monitoring sites that represent conditions over large landscapes surrounding a flux or process site. An additional important function of Tier 2 is to augment coverage of the land surface by flux towers, which have limited representation of mountainous terrain and highly disturbed landscapes. Tier 1- Intensive Sites LTER ≈ 24 sites, AmeriFlux ≈ 50 flux tower sites Continuous monitoring Tier 2- Medium-intensity landscape sampling Goal: new network of ≈1000 landscape monitoring sites Pilot studies initiated in Spring, 2004 Bartlett NH, Marcell MN, Fraser & Niwot CO, GLEES WY, Parker Tract NC Tier 3- Extensive inventory USDA Forest Service FIA plots ≈125,000 plots nationally, measured every 5-10 years Tier 4- Mapping and Remote Sensing (land cover/use; change detection) Continental-scale coverage, varying spatial and temporal resolution Tier 2 measurements facilitate scaling, in time and space, of intensive measurements to broader landscapes. Key measurements at Tier 2 include: 1.Soil C flux, a response to soil respiration which is strongly regulated by climate and disturbance, and accounts for about 1/3 of the total land/atmosphere C flux; 2.Methane flux, an important greenhouse gas particularly in peatlands, wetlands, and agricultural systems; 3.Basic meteorological and site biometric (soil, vegetation) parameters to enable linkage with similar Ameriflux sites. The USDA Global Change Program, in 2004, sponsored several pilot projects (Fig. 1) in diverse U.S. forest ecosystems to examine the potential of sites with intensive ground-based measurements to aid in the development of landscape level carbon flux estimates. A workshop, with 40+ participants representing a cross section of government agencies, academia, and nonprofit research organizations from the U.S., Canada, and Mexico, was held in Portsmouth, NH in June, 2003 to develop the sampling design and initial variable list for forest carbon monitoring at Tier 2 sites. The proposed design consists of a 1-km 2 area surrounding a flux tower or other significant feature of an intensive research site, over which a grid of sample plots is located (Fig. 2).The basic sample plot is identical to that of tier 3, (e.g FIA plot design) with enhancements to add the new variables for extending intensive measurements to the landscape. Figure 1. Locations of pilot studies for enhanced forest land measurements. Sites are established forest ecosystem study areas including USFS experimental forests (Bartlett EF, NH; Marcell EF MN, Fraser EF, CO; GLEES, WY), LTER sites (Niwot Ridge, CO), and industry research areas (Parker Tract, NC). In addition to testing Tier 2 measurement protocols, the BEF study (Fig. 2) investigates methods for scaling from intensive sites to landscapes using tiered multi- and hyper-spectral remote sensing, the PnET ecosystem process model, and extensive networks of field plot data. Established in 1932, BEF has been actively monitored for 70+ years, and includes a variety of forest management treatments that represent typical activities of the region. A new flux tower was installed at BEF in November, 2003 and has been in continuous operation since January, 2004. Tier 2 plot measurements began in April, 2004 BEF NACP Sampling Design 1 km x 1 km area centered on flux tower, containing a 3 x 4 grid of 1 hectare sampling plots 4 10m radius sub-plots, based on FIA sample design, within each 1 ha macro-plot. Measurements initiated 2004: –Aboveground biomass: tree/sapling species and DBH, seedling counts; yearly –3 permanent soil respiration collars per sub-plot (144 total); biweekly measurement – 3 coarse woody transects per macro-plot; 3 methods –Litter and branch fall –Foliar sampling (chemistry, LMA) –Leaf area and gap fraction (direct and indirect, optical) –Canopy foliage profiles Measurements planned for 2005: –Continue measurements suites initiated in 2004 –Soil C pools and turnover, bulk density, nutrients –Roots and mycorrhizae A. Intensive Forest Measurements 120 m 200 m 60 m ABCD 1 2 3 Figure 2. Location of a.) regional forest ecosystem monitoring sites in the northeastern U.S.; b.) the Bartlett Experimental Forest (BEF) within the White Mountain National Forest; and c.) long-term and eddy covariance monitoring sites at the BEF in relation to forest species distribution and topographic relief. 1 km 2 intensive sampling area centered on CO 2 flux tower. 4 10m radius FIA type sub-plots within 1 ha macro-plot. B. Tower-Based Measurements Flux Measurements 25 m high tower Constructed October 2003; instrumented January 2004 12V DC system run on solar power Provides continuous above-canopy monitoring of ecosystem fluxes: CO 2, H 2 O, and energy Using eddy covariance technique, which relies on high-frequency (5 Hz) measurements of wind components and CO 2 Modeling to partition CO 2 flux into respiration and gross photosynthesis Meteorological and Other Measurements Air temperature (above and below canopy) and relative humidity Solar radiation: –Incident and canopy-reflected total PAR & global radiation –Diffuse and direct beam PAR –Net radiation –Below-canopy array (x6) to measure transmitted PAR Soil temperature (x 6) and soil moisture (x 4) Canopy wind profile (4 sensors) Rain gauge Canopy reflectance 400-1100 nm @ 256 wavebands NACP pilot studies are supported by the Global Change Program of the USDA Forest Service and by the NASA Carbon Cycle Science Program Acknowledgements Bob Evans, John Richardson, Christine Costello, Julian Jenkins and Rob Braswell are thanked for assistance with tower construction and maintenance. Andy Friedland, Dartmouth College, kindly loaned several of the data loggers and sensors used on the tower. Some Initial Tower Sample Results