The goal of the project is to understand the role of root distributions for carbon, water, and nutrient fluxes and to improve the representation of belowground processes in global models. A new synthesis of global rooting patterns and soil attributes and their use in global models (Canadell et al. 1996; Jackson et al. 1996; Jackson et al. 1997; Jackson 1999; Gordon and Jackson 2000; Hoffmann and Jackson 2000; Jackson 2000; Jackson et al. 2000; Jobbágy and Jackson 2000) provides the starting point for some of the activities. Projects based at Duke University and UCSB's National Center for Ecological Analysis and Synthesis include a cross-model comparison (site-specific and global) and the preparation of several global rooting maps. Participating labs and models include BATS (Robert Dickinson), BIOME3 (Martin Sykes and Colin Prentice), BIOME-BGC (Steve Running), CASA/SIB2 (Chris Field and Joe Berry), Century (Bill Parton), MAPSS (Ron Nielsen), TEM (Dave Kicklighter), and models of Martin Heimann and Axel Kleidon. For further information on the modeling goals, see: NCEAS, funded proposals. Accompanying the project is field work in Patagonia and South Africa, where collaborators are Martyn Caldwell, Pep Canadell, Jim Ehleringer, Hal Mooney, Osvaldo Sala, and Detlef Schulze.
The activity is funded by NCEAS, NSF, and the Andrew W. Mellon Foundation and contributes to the GCTE (Global Change and Terrestrial Ecosystems), BAHC (Biosphere Aspects of the Hydrological Cycle), and GAIM (Global Analysis, Interpretation, and Modelling) core projects of the International Geosphere Biosphere Programme (IGBP). Contacts at BAHC and GAIM are Reinder Feddes and Holger Hoff (BAHC) and Kathy Hibbard (GAIM).
The map above shows the proportion of root biomass globally in the upper 30 cm of soil.
Bibliography
Canadell, J, RB Jackson, JR Ehleringer, HA Mooney, OE Sala, & E-D Schulze 1996 Maximum rooting depth of vegetation types at the global scale. Oecologia 108:583-595.
Gordon WS, RB Jackson 2000 Nutrient concentrations in fine roots. Ecology 81:275-280.
Hoffmann WA, Jackson RB 2000 Vegetation-climate feedbacks in the conversion of tropical savanna to grassland. Journal of Climate 13:1593-1602.
Jackson, RB 1999 The importance of root distributions for hydrology, biogeochemistry, and ecosystem functioning. In (J Tenhunen, P Kabat, eds., Dahlem Conference) Integrating hydrology, ecosystem dynamics, and biogeochemistry in complex landscapes. John Wiley and Sons, Chichester, pp. 219-240.
Jackson RB 2000 Belowground processes and global change. Ecological Applications 10:397-398.
Jackson, RB, J Canadell, JR Ehleringer, HA Mooney, OE Sala, & ED Schulze 1996 A global analysis of root distributions for terrestrial biomes. Oecologia 108:389-411.
Jackson, RB, HA Mooney, & ED Schulze 1997 A global budget for fine root biomass, surface area, and nutrient contents. Proceedings of the National Academy of Sciences, USA, 94:7362-7366.
Jackson RB, HJ Schenk, EG Jobbagy, J Canadell, GD Colello, RE Dickinson, CB Field, P Friedlingstein, M Heimann, K Hibbard, DW Kicklighter, A Kleidon, RP Neilson, WJ Parton, OE Sala, MT Sykes 2000 Belowground consequences of vegetation change and their treatment in models. Ecological Applications 10:470-483.
Jobbágy EG, Jackson RB 2000 The vertical distribution of soil organic carbon and its relation to climate and vegetation. Ecological Applications 10:423-436.
Stone, EL, PJ Kalisz 1991 On the maximum extent of tree roots. For. Ecol. Manage. 46:59-102.
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Last modified 28 September 2000
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