A Floristic Comparison of Vascular Species in Tasmanian Oldgrowth Mixed Forest With Regeneration Resulting From Logging and Wildfire

Abstract

About 20% of Tasmania's wet eucalypt forest is mixed forest, i.e. having a rainforest understorey and a eucalypt overstorey. While one-third of the mixed forest is formally reserved, much of the remainder is subject to logging on an 80-100 year rotation which is insufficient for the redevelopment of mature mixed forest. The routine silvicultural regeneration treatment for wet eucalypt forests is to clearfell, burn and sow with eucalypt seed. A comparison of the Vascular floristics of 20-30-year-old silvicultural and wildfire regeneration with oldgrowth mixed forest showed that most species common in oldgrowth mixed forest were represented in approximately similar frequencies in silvicultural regeneration and wildfire regeneration. The major floristic difference between the two regeneration types was the much lower frequency of oldgrowth epiphytic fern species in silvicultural regeneration and a higher frequency of a sedge species often associated with disturbed areas. However, after a single logging treatment, the vascular plant floristics of silvicultural regeneration were sufficiently similar to wildfire regeneration to assume that, in the absence of further logging or fires, the silvicultural regeneration could become mature mixed forest and eventually rainforest. Further work is required to determine whether regrowth mixed forest can be logged at 80-100 years and still retain sufficient rainforest elements to eventually return to mixed forest within the life span of the dominant eucalypts. The critical factor in the silvicultural perpetuation of mixed forest may be rotation length rather than regeneration treatment.

Decline in tree-fern abundance after clearfell harvesting

“…Several authors have reported reduced occurrence or absence of epiphytic ferns after harvesting (e.g. Harris, 1989;Ough and Ross, 1992;Hickey, 1994). Tree-ferns greater than 1.5 m tall support epiphytic species much more commonly than smaller tree-ferns (personal observation).…”

Impacto do efeito de borda sobre a comunidade de samambaias epifíticas em floresta com araucária

“…Eles são considerados importantes indicadores ecológicos e o seu monitoramento permite avaliar os efeitos da perturbação florestal (TURNER et al, 1994;HICKEY, 1994;HIETZ, 1999) bem como o seu estágio sucessional (KERSTEN & KUNIYOSHI, 2009). …”

Genetic differentiation in spite of high gene flow in the dominant rainforest tree of southeastern Australia, Nothofagus cunninghamii

“…Under scenario 3 the populations diverged 224 generations ago (T1, median value), the effective population size of Tasmania was nearly eight times larger than the central highlands Victoria (9500 versus 1230, respectively, median values; see Supplementary Tables S3 and S4 and Supplementary Figure S7 for detailed results of approximate Bayesian computation analysis). This implied a divergence time of 22 400 years ago assuming the generation time of 100 years estimated by Hickey (1994). Mean relative bias values were generally low ( Supplementary Table S3) indicating that estimates are relatively accurate.…”