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Publications in 2005. Zheng D, Chen J, Noormets A, Euskirchen ES, LeMoine J (2005) Effects of climate and land use on landscape soil respiration in northern Wisconsin, USA: 1972 to 2001. Climate Research 28, 163-173.
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Publications in 2005 Zheng D, Chen J, Noormets A, Euskirchen ES, LeMoine J (2005) Effects of climate and land use on landscape soil respiration in northern Wisconsin, USA: 1972 to 2001. Climate Research28, 163-173. Zheng D, Chen J, LeMoine J, Euskirchen ES (2005) Influences of land-use change and edges on soil respiration in a managed forest landscape, WI. Forest Ecology and Management, In press. * Ryu S-R, Chen J, Noormets A, Bresee MK, Ollinger SV (2005) Comparisons and insights of predicted (PnET-Day) and measured gross carbon exchange in northern Wisconsin forests. Agricultural and Forest Meteorology, Submitted. * Sun G, Noormets A, Chen J, McNulty SG (2005) Forest ecosystem evapotranspiration across a management gradient in northern Wisconsin, USA. Agricultural and Forest Meteorology, Submitted. * Noormets A, Desai A, Cook BD, et al. (2005) Moisture sensitivity of ecosystem respiration: comparison of 14 forest ecosystems in the Upper Great Lakes Region, USA. Agricultural and Forest Meteorology, Submitted. Noormets A, Chen J, Crow TR (2005) Age-related changes in forest carbon fluxes in a managed northern Wisconsin landscape. Journal of Geophysical Reseach - Biogeosciences, Revisions. * ChEAS special issue of Agricultural and Forest Meteorology
Ongoing and planned efforts Physiological control of ecosystem fluxes • Ecosystem- and leaf-level gas exchange: comparison of capacities, sources of discrepancies • Fluxes in ecosystem edges Effects of man-made disturbance • Recovery of C fluxes after disturbance • Regulation of ecosystem respiration Landscape integration of carbon and water cycles • NEP changes over succession • Ecosystem water cycle • Landscape-level PnET modeling • Effects of land-use change on landscape C balance
Regulation of ecosystem respiration Asko Noormets The University of Toledo
Regulation of ER - AFM summary Ts explained ~43% of variation in ER (range 8-82%) SWC explained 8% (range 0-21%) • M-sensitivity occurred in: • all age groups • both forest types (hardwoods & conifers) • M-sensitivity was: • Greatest in Willow Creek & Sylvania sites • Intermediate in IRP, IHW, YJP-Baraga & YHW • Not significant in other sites (12 site-years)
Moisture-sensitivity of ER Moisture response was: • non-linear • correlated with well-defined moisture optimum • correlated with bi-modal SWC distribution
What are the other factors? • Substrate availability? • Auto- vs. heterotrophic? • Chemical vs. physiological control?
Seasonality of ER • Seasonal cycle of ER parallels the cycle of soil moisture (most mature stands) • Seasonal cycle in ER goes against the cycle of soil moisture (some young stands)
Seasonality of ER • Seasonal cycle of ER parallels the cycle of soil moisture (most mature stands) Hypothesis: Moisture-limited ER • Seasonal cycle in ER goes against the cycle of soil moisture (some young stands) Hypothesis: Substrate-limited ER
Phenology: physical vs. physiological control&auto- vs. heterotrophic processes
Ecosystem ER • Bounds of physiological regulation • Partitioning the limitation to other factors • Substrate dynamics • ChEAS-specific • Assemble regional • C budget 2. General Mechanistically explain ER
ChEAS-wide activities • Comparison of flux processing algorithms (Cherrey, Saliendra et al.) • Comparison of respiration models • Comparison of gapfilling procedures
Growing season C budget GEP NEE ER