The Influence of Fertilisation on Ectomycorrhizal Colonisation ofPinus patularoots

SYNOPSIS Mycorrhizal fungi play an important role in supplying the host plant with nutrients. The presence of mycorrhizal fungi can also confer a number of other advantages on the host such as drought, disease and heavy metal tolerance. Mycorrhizal colonisation is sensitive to small changes in the soil environment, hence factors which disrupt the mycorrhizal balance could have a negative influence on the host. An investigation into the effect of fertiliser application on the degree of mycorrhizal colonisation and the mycorrhizal species abundance of Pinus patula roots, at three plantations, was investigated. The number of mycorrhizal tips per length of root was calculated for each species present. The results indicate that although the total number of mycorrhizal tips was not affected by the application of fertiliser, the species abundance did change. The effect that the change in species abundance has on the efficiency with which the host is supplied with nutrients, is unknown at this stage.