FIGURE 6.3 PC analysis of the effects of added nitrogen fertilizer, simulating atmospheric nitrogen deposition in a NITREX experiment in Sweden. The top two analyses are treatment plots in ectomycorrhizal fruit body species space, showing the nitrogen-treated plots having a different community structure than the untreated control plots. The third analysis is similar, but uses mycorrhizal community structure based on molecular identification of root tips. This latter analysis shows less difference in mycorrhizal community structure between unfertilized and fertilized plots. Source: Data compiled from Brandrud (1995) and Jonsson (1998).

ABSTRACT

Clitocybe, Lepista, Agaricus, and Lycoperdon (Fig. 6.4). A possible explanation for this is the increased availability of N to stimulate the decomposition of a recalcitrant leaf litter species.

From these results we can infer that the addition of nitrogen has a greater effect on the ability of basidiomycete fungi to produce fruiting structures than it has on changes in soil

chemistry and consequent changes in mycorrhizal fungal colonization of root tips. The function of the ectomycorrhizal community (enzyme production, rate of nutrient uptake, degree of protection of host plant to root pathogens, fungal hyphal growth, etc.) as a result of altered soil conditions has not been fully investigated, however.