A 4300 year palynological and sedimentological record of environmental change and human impact from Wharau Road Swamp, Northland, New Zealand

The Kaharoa Tephra as a Critical Datum for Earliest Human Impact in Northern New Zealand

“…Bussell, 1988;McGlone, Neall & Clarkson, 1988;Newnham, 1990;Alloway et al, 1992;McGlone & Neall, 1994). In contrast, the Northland region, where some models predict the earliest prehistoric sites should be found (see above), has a comparatively impoverished macroscopic tephra record, although some important central North island-sourced tephra layers have been found (Rankin, 1973;Pullar, Kohn & Cox, 1977;Lowe, 1988b;Elliott et al, 1997;Newnham, Lowe & Alloway, 1997;Newnham, in press). There is also considerable potential in Auckland to construct local Holocene tephropalynological sequences using the basaltic tephras of the Auckland Volcanic Field (Newnham & Lowe, 1991;Newnham, Lowe & Alloway, in press).…”

“…All are from the Waikato, Bay of Plenty, Poverty Bay and Hawke's Bay regions (Figure 2). Two further pollen profiles from the Bay of islands, Northland (Chester, 1986;Elliott et al, 1997) that contain Kaharoa Tephra tentatively identified may point to the wider potential of this tephra in northern New Zealand. Using the palynological criteria discussed by McGlone (1983a) to determine the earliest unequivocal pollen-spore spectra implying human-induced deforestation, we show that the eleven pollen profiles with definite Kaharoa Tephra fall into two groups, as described below.…”

“…Under this scenario, which has been described at other sites of similar depositional setting conducive to inwash (e.g. McFadgen, 1996;Elliott et al, 1997;McGlone & Wilmshurst, in press), the younger date on material immediately above the silt layer might be considered more reliable.…”

Late Quaternary environments, vegetation and agriculture in northern New Zealand

“…Previous far northern pollen studies (e.g. Elliot et al, 1997;Horrocks et al, 2001;Newnham et al, 2004) suggest that regional Polynesian deforestation occurred at a similar time to that of much of New Zealand generally, ca. 800-600 yr BP (McGlone, 1983;McGlone and Wilmshurst, 1999).…”

“…Agathis also expanded after this time. Other pollen records from the southern part of the region, notably from the Bay of Islands and Whangape Harbour (Elliot et al, 1997Horrocks et al, 2001Horrocks et al, , 2007 (Fig. 1), together cover much of the Holocene, showing Dacrydium-dominated conifer-hardwood forest undergoing large-scale destruction by Polynesian fires during the last millennium.…”