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1. Sap flux scaled canopy transpiration, stomatal conductance and water use efficiency in an old-growth forest in the Great Lakes region. 2. Carbon allocation in an old-growth hemlock- northern hardwood forest in the Great Lakes region. Jianwu Tang and coauthors. Ongoing projects.
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1. Sap flux scaled canopy transpiration, stomatal conductance and water use efficiency in an old-growth forest in the Great Lakes region 2. Carbon allocation in an old-growth hemlock- northern hardwood forest in the Great Lakes region Jianwu Tang and coauthors
Ongoing projects • Respiration, production, and carbon allocation in Sylvania, Willow Creek, and Lost Creek: spatial variation and successional patterns • Canopy transpiration, stomatal conductance, and water use efficiency • Cross-site soil respiration and automated measurement of soil respiration (half-hour): diurnal and seasonal variations and controls • Upscaling: • Comparing Century-type carbon modeling with site measurements • Comparing high-resolution-imagery-based upscaling with site measurements
Transpiration – stomatal conductance – photosynthesis Transpiration – water use efficiency – photosynthesis
Granier (1987) Ewers et al. (1999); Oren et al. (1998) Monteith and Unsworth (1990)
Carbon allocation • Important in ecosystem carbon modeling: fixed allocation or not? • Important in ecological theory: Odum, 1969, Science Ryan et al. 1997, Ad. Eco. Res.
a: autotrophic, h: heterotrophic, w: wood, f: foliage, r: root, s: soil
Hardwood stand Hemlock stand Wood 12,548 14,232 Bole 9,555 11,998 Branch 2,993 2,234 Foliage 150 162 Roots (live and dead) 701 700 Fine roots 288 184 Coarse roots 413 516 Sum 13,399 15,094 Carbon (g C m-2) stored in forests
Species Hardwood stand Hemlock stand Wood Foliage Wood Foliage Sugar maple 54 (64%) 93 (73%) 2 (2%) 3 (4%) Hemlock 10 (12%) 11 (8%) 81(85%) 47(67%) Yellow birch and others 20 (24%) 24 (19%) 12(13%) 20(29%) Sum 84 (100%) 128(100%) 95(100%) 70(100%) NPP (g C m-2 y-1) from wood and foliage for three species and their percentages in the hardwood and hemlock stands
Species Hardwood stand Hemlock stand Wood Foliage Wood Foliage Sugar maple 86 (66%) 80 (69%) 9 (4%) 3 (4%) Hemlock 13 (9%) 12 (11%) 169(82%) 50(69%) Yellow birch and others 32 (25%) 23 (20%) 28(14%) 19(27%) Sum 131(100%) 115(100%) 206(100%) 72(100%) Respiration per ground area (g C m-2 y-1) from wood and foliage for three species and their percentages in the hardwood and hemlock stands
Conclusion • Component respiration and production vary with ecosystem type and stand age. • Transpiration studies can be coupled to carbon studies.