ABSTRACT
Suillus bovines, found in nitrogen-poor environments, Gorisen and Kuyper (2000) demonstrated a greater net accumulation of carbon in plants associated with both mycorrhizal species. That extra carbon, however, was translocated below ground and incorporated into root and fungal biomass in Suillius mycorrhizae, but the additional carbohydrate translocated into Laccaria colonized roots was respired. The plant return for the carbon investment in Suillus-colonized root biomass was an increase in nitrogen uptake, resulting in plant N contents twice as high as Laccaria-colonized trees, irrespective of CO2 concentration. These results lend support to the concept that carbon use for nitrogen acquisition is more important in mycorrhizal symbiosis that are characteristic of N-limiting ecosystems.
