ree belowground carbon (C) allocation is a major route of C
flow in forest stands, often accounting for 35–80% of the C
assimilated (Raich and Nadelhoffer 1989, Davidson et al. 2002,
Giardina et al. 2003, Ryan et al. 2004).
Carbohydrates transported by the phloem to roots provide
energy for a suite of physiological process of roots and attached
microbial partners including mycorrhizal fungi (Björkman 1944,
Colpaert et al. 1996, Binkley et al. 2006, Martin and Slater