Yeasts associated with the New Zealand Nothofagus honeydew system

New Zealand honeydew beech forests are the only natural ecosystem where large quantities of above-ground labile carbon are added year-round. Microbes can potentially play an important role in the flux of nutrients through food webs; because of their potential for specialisation to sugar-rich niches we tested for the presence of yeasts in the honeydew system. We found at least two abundant species (Hanseniaspora osmophila and Candida railenensis), as well as two species (Zygosaccharomyces cidri and Z. rouxii) likely present at lower frequencies. Only Candida railenensis is known to be associated with Nothofagus, but the other species are associated with fruits and winemaking/fermentation. These other species found in honeydew may be indigenous, but it is also possible that they represent microbial examples of invasive species and consequently add to the considerable list of human-introduced species that have invaded New Zealand’s ecosystem.