Mycorrhizal Associations of Plant-Species in Hawkesbury Sandstone Vegetation

Abstract

The mycorrhizal associations of plant species in an open woodland and heathland on Hawkesbury Sandstone soils were examined. The two geographically disjunct sites supported vegetation of differing physiognomy, but possessed many species common to both sites. At the woodland site, 21 of the 32 plant species examined had mycorrhizal associations. At the heath site, 31 of the 47 plant species examined were mycorrhizal. Mycorrhizal associations were found on representatives of the Cyperaceae and Proteaceae, families not previously thought to be mycorrhizal. Internal hyphae, vesicles, and cortical hyphal coils were discovered on the roots of two species of Cyperaceae and on the non-proteoid roots of nine species of the Proteacae. Several species within genera and families previously known to be mycorrhizal were also found for the first time to have associations. Endomycorrhizal associations predominated at both sites, but several species had both ecto- and endomycorrhizal associations. The presence or absence of mycorrhizal associations was consistent on the roots of those plant species common to both sites examined.