Recruitment of Eucalyptus strzeleckii (Myrtaceae) in remnant patches of native vegetation in the Latrobe Valley and South Gippsland, Victoria

Abstract

Eucalyptus strzeleckii K.Rule (Strzelecki gum) is a medium to tall, forest swamp gum endemic to the foothills and flats of southern Victoria. It is listed as Vulnerable at State (Victoria) and Federal levels. Many of the existing populations are dominated by mature, senescing trees in highly degraded habitats and recruitment of the species is rarely observed. The present study assessed the natural recruitment of Strzelecki gum at locations where mature Strzelecki gums are present and habitat degradation is not a significant limiting factor. The number of mature and recruiting Strzelecki gum individuals was assessed within gradient-oriented belt transects (gradsects) and a range of variables considered to be likely to affect recruitment were measured and correlated with the results of the recruitment study. Strzelecki gum recruits (<5 m tall) were found in 68.8% of gradsects and recruits accounted for 8–14% of the total stems counted for this species. Areas that had been recently burnt (within the past 5 years) had 15 times the number of Strzelecki gum recruits. Disturbance by flooding may also be positively associated with recruitment. Litter cover, habitat quality and density of intermediate-sized Strzelecki gums were all strong positive predictors for the density of Strzelecki gum recruits. Results from the present survey have provided a basis for land managers to estimate quantities of mature and recruiting Strzelecki gums in large populations.