Are the patterns of regeneration in the endangered Eucalyptus gunnii ssp. divaricata shifting in response to climate?

The eco-evolutionary risks of not changing seed provenancing practices in changing environments

Sourcing seed from local populations has been the long-standing default for native restoration plantings for numerous eco-evolutionary reasons. However, rapidly changing environments are revealing risks associated with both non-local and local provenancing. As alternative strategies gain interest, we argue to progress seed sourcing discussions towards developing risk-based decision-making that weighs the risks of changing and not changing in a changing environment, transcending historic default positions and local versus non-local debates.

Microsite Drivers of Natural Seed Regeneration of Eucalyptus globulus Labill. in Burnt Plantations

Fire regimes are changing in several regions of the world. In those regions, some exotic species may be better adapted to new regimes than the native species. This study focused on identifying the microsite characteristics associated with the occurrence of post-fire Eucalyptus globulus regeneration from seeds, outside the species native-range. This information is important in helping to assess the naturalization status of the species, to understand its invasion risk, and to manage wildlings in plantations. To characterize the establishment niche, pairs of microsites (sapling presence/absence) were sampled in four salvage-logged plantations of E. globulus two years after fire (20 pairs/plantation). Microsites of wildlings from three size classes and control microsites were established in one of these plantations (20 quartets) in order to characterize the recruitment niche and to assess ontogenic niche shifts. Two post-fire wildling cohorts were identified. The first emerged just after fire and was abundant. The second emerged after logging and was scarce, probably due to seed limitation. First-cohort wildlings were observed in microsites characterized by a high incidence of fire-related variables (charcoal, ash, increased soil pH and K). The aggregated distribution of these wildlings and their association with other species may indicate the existence of facilitative relationships and/or the exploitation of resource-rich patches. All these factors were relevant for first-cohort persistence and likely also for its establishment and recruitment. Second-cohort wildlings occurred in microsites where salvage-logging disturbance was evident, showing the importance of this disturbance for its emergence. Wildling size diversity was explained by the two recruitment events and by the asymmetrical competition between wildlings and adults. No niche shifts were detected. The high densities of E. globulus wildlings found established in burnt plantations indicated naturalization was in progress. The timing of major recruitment events and the phenology of the species should be considered for monitoring this regeneration and scheduling control interventions, if required.

Discovering the indigenous microbial communities associated with the natural fermentation of sap from the cider gum Eucalyptus gunnii

Over the course of human history and in most societies, fermented beverages have had a unique economic and cultural importance. Before the arrival of the first Europeans in Australia, Aboriginal people reportedly produced several fermented drinks including mangaitch from flowering cones of Banksia and way-a-linah from Eucalyptus tree sap. In the case of more familiar fermented beverages, numerous microorganisms, including fungi, yeast and bacteria, present on the surface of fruits and grains are responsible for the conversion of the sugars in these materials into ethanol. Here we describe native microbial communities associated with the spontaneous fermentation of sap from the cider gum Eucalyptus gunnii, a Eucalyptus tree native to the remote Central Plateau of Tasmania. Amplicon-based phylotyping showed numerous microbial species in cider gum samples, with fungal species differing greatly to those associated with winemaking. Phylotyping also revealed several fungal sequences which do not match known fungal genomes suggesting novel yeast species. These findings highlight the vast microbial diversity associated with the Australian Eucalyptus gunnii and the native alcoholic beverage way-a-linah.