The East Gippsland Silvicultural Systems Project II: Germination and early survival of eucalypt regeneration

Abstract

Summary A major silvicultural experiment has been established in lowland forest in East Gippsland to evaluate alternative silvicultural systems. A range of harvesting and site preparation treatments was applied in a replicated design over two seasons. Harvesting treatments consist of a series of gap sizes (0,0.03,0.25 and 1-ha gaps, 4- and 10-ha clearfells) and retained overwood (clearfell and 7, 22, 35 and 100% retained basal area). Results of site preparation by slash burning and mechanical disturbance were compared. A primary criterion for evaluation of these treatments was the successful establishment of eucalypt regeneration. Eucalypt germination and seedling establishment was monitored biannually for 3 y. Germination, survival, seedling stocking and height growth were significantly influenced by gap size or the amount of overwood retained. Total germination was largely a function of seed supply, increasing with increasing overwood retention and decreasing gap size. Its response to site preparation method was confounded by seasonal effects. Total stocking at age 3 y generally reflected these germination results, although percent survival increased with increasing gap size and decreasing retained overwood. Mean height of seedlings at age 3 y also increased with increasing gap size and decreasing retained overwood. All treatments had successfully regenerated at 3 y, although survival and growth were significantly lower in the less intensively harvested treatments.