Mycorrhizal plants dominate in most ecosystems and they differ in belowground carbon allocation, capacity of organic nutrient acquisition, impact on soil carbon, and nutrient cycling. So far, to improve our understanding of mycorrhizal contributions to soil C and nutrient cycling, most research has been carried out in very different biomes (e.g., arbuscular mycorrhizal grasslands vs ectomycorrhizal boreal forests). In forest ecosystems, nutrient availability generally limits the primary production. To cope with this nutrient limitation, plant carbon investment into mycorrhizal fungi is considered as the main strategy. Hence, mycorrhizal fungi, through their own nutrient acquisition strategies, will create new key functional traits at both individual plant and ecosystem level, with global consequences on nutrient cycling. Here, we aimed at reviewing recent data concerning the mechanisms, direct and indirect, that allow mycorrhizal fungi to access nitrogen and phosphorus from organic sources in forest soils and thus contribute to the recycling of N and P toward their host tree. We show that arbuscular mycorrhizal and ectomycorrhizal fungi display substantial differences in their strategies to acquire phosphorus and nitrogen from soil organic matter. Finally, we show that data illustrating the importance of the two major guilds of mycorrhizal fungi, their fundamental differences, and their relative importance in biogeochemical processes are beginning to accumulate.