Variation in estimates of quadrat stocking with time in regenerated coupes of ash eucalypts.  B. A. Wehner.  November 1984.  10 pp + App. (unpubl.)

SUMMARY

The reliability of the stocked 4-milacre quadrat method for assessing eucalypt regeneration stocking on coupes one year after seeding, was investigated by re-examination of coupes at ages 2, 3, 4, 7 and 10 years after seeding.

Four coupes were chosen in the 7-year-old age-class and five coupes in each of the remaining age-classes, unevenly distributed in Toolangi, Alexandra and Upper Yarra Forest Districts, and seeded with Eucalyptus regnans F. Muell. (mountain ash), E. delegatensis R. T. Baker (alpine ash), or both.

On reassessment, the stocking on coupes aged 2 and 3 years was found to be significantly higher (P < 0.05) than those recorded at age 1. In contrast, on coupes aged 4 and 10 years, stocking was not significantly different than those at age 1. On the 7-year-old coupes, the average stocking was significantly less (P < 0.05) than had been recorded at age 1, though the reduction was attributable to abnormal mortality on one coupe, with the remaining three coupes showing little variation from stocking at age 1.

Although the precise reasons for the increases in stocking observed on coupes aged 2 and 3 years are not clear, an analysis of seedling heights on stocked quadrats aged 2 and 3 years suggested that continuing germination after age 2 was not a significant contributing factor. Further study is necessary to identify the reasons for these observed increases in stocking and to ensure that regeneration surveys are achieving their intended purpose.