Benchmark stem densities for forests and woodlands in south-eastern Australia under conditions of relatively little modification by humans since European settlement

Benchmarks of fallen timber and man's role in nature: Some evidence from eucalypt woodlands in southeastern Australia

“…On the single occasion when Oxley (1820) was obstructed by fallen timber on land, the lack of evidence of human economy prompted him to declare it a "truly primeval forest". In contrast, 41% of the remnant 'woodlands' and forests studied by Gibbons et al (2008Gibbons et al ( , 2010 had no evidence of fire and only 2% had evidence of recent fire. Studies of fallen timber in purported woodlands were in fact conducted in forests developing in a landscape starved of fire (e.g.…”

“…Mooney et al (2010) found that post-European charcoal deposition rates declined under recent prescribed burning regimes but unaccountably dismissed historical records of frequent and extensive burning by Aborigines on the basis of low pre-European deposition rates. Gibbons et al (2008Gibbons et al ( , 2010 uncritically dismissed historical information about vegetation structure as tainted by subjectivity and pecuniary interest, qualitative and unsystematic. They suggested that diameter distributions of trees in eucalypt woodlands and open forests should have the reverse J form typical of unmanaged stands.…”

“…For example, canopy cover averages 27% across red gum -yellow box stands in the region around Yass Plains and ranges up to 57% for 'minimally disturbed' stands (McElhinney et al, 2006). All types of woodland assessed by Gibbons et al (2008Gibbons et al ( , 2010 had tree densities typical of forests (104-614 stems ha −1 ) and an order of magnitude higher than pre-European woodlands (Jurskis, 2009). However most trees were small (<40 cm dbh) whilst densities of larger trees (average 27 ha −1 Gibbons et al, 2008, Table 5) were typical of stand densities in Aboriginal woodlands (∼30 ha −1 Wallis, 1878;Donovan, 1997;Lunt et al, 2006;Jurskis, 2009) confirming that woody thickening had occurred after human economy was excluded.…”

“…Jurskis (2009) analysed these explorers' records to describe the pre-European landscape and provide context for an environmental assessment of current forestry management in south western New South Wales. This region has been the focus of several benchmarking studies of fallen timber and vegetation structure (Robinson, 1997;MacNally et al, 2001;Lunt et al, 2006;Gibbons et al, 2008Gibbons et al, , 2010. The current analysis compares these against the historical information and also compares current data from similar woodlands around Yass Plains (McElhinney et al, 2006;Manning et al, 2007;Killey et al, 2010) against the original description by Hume and Hovell (Bland, 1831).…”

Empirically validating a dense woody regrowth ‘problem’ and thinning ‘solution’ for understory vegetation

“…In Australia and North America, these benchmarks typically represent vegetation http://dx.doi.org/10.1016/j.foreco.2014.12.006 0378-1127/Ó 2014 Elsevier B.V. All rights reserved. states predating European arrival (Eyre et al, 2011;Gibbons et al, 2010;Gibbons and Freudenberger, 2006;Jackson et al, 2000;Parkes et al, 2003;Wallin et al, 2004). In Australia for example, spontaneous woody regrowth is positively received while the plants are young but there is concern about the biodiversity and habitat value of these simplified stands as they age (e.g., Geddes et al, 2011;Kyle and Duncan, 2012).…”