What changing: population size or land-use patterns The archaeology of Upper Mangrove Creek, Sydney Basin1985, 1988; Flood et al. 1987; Barker 1991; David and Chant 1995: 361�, 437�; David 1990: 90�; Ross et al. 1992: 109; Lourandos and Ross 1994) as well as opponents and critics, especially in terms of the forms of evidence and sources used (e.g., Rowland 1983: 72�, 1989: 40; Yoffee 1985: 177�0; Hall and Hiscock 1988b: 16�9; Davidson 1990; Bird and Frankel 1991a; Sutton 1990; Williamson 1998: 144�; Mulvaney and Kamminga 1999: 270�; Lilley 2000). Changing numbers of sites and artefacts are often involved in the proposed explanatory and interpretive models at a continental, regional or site level. Climatic and/or environmental changes are often involved in explanations as well, and, in this regard, regionalisation, risk minimisation and changes in mobility patterns are now used increasingly as contexts in which alternative models and hypotheses are proposed for changing numbers of sites and artefacts in association with other archaeological evidence. This chapter focuses on studies of the 1970s and 1980s in which changing numbers of sites and artefacts were the principal lines of evidence for claims of dramatic increases in population size (at a continental, regional or site-specific level), as well as part of the archaeological evidence on which the concept of late Holocene intensification was formulated. In analysing archaeological evidence from the Upper Mangrove Creek catchment, I calculated several indices that document temporal changes in numbers of sites and artefacts. These indices are referred to as: 1. the rate of habitation establishment; 2. the number of habitations used; and, 3. the rate of artefact accumulation. I refer to changes in these indices collectively as he quantitative changes in�or he quantitative aspects of�the archaeological record (for methods of calculation, see Chapter 6). These terms have not been employed by all researchers, and other terms used include changes in the number of sites occupied, increases through time in numbers of sites and artefacts, changes in the concentrations of artefacts, changes in discard rates, changes in the intensity of site use, and changes in intensity of occupation (with more sites, artefacts and people). Many researchers proposed or accepted that in Australia there was a continuing increase over time in the number of archaeological sites (especially habitation sites) established and/or used in various regions, and/or in the number of artefacts accumulated in individual sites, particularly in the last 5000 years (Johnson 1979: 39; Bowdler 1981; Morwood 1984: 371, 1986, 1987; Ross 1984, 1985: 87; Beaton 1985: 16�8; Fletcher-Jones 1985: 282, 286; Lourandos 1985a: 393�11, 1985b: 38; White and Habgood 1985; see also discussion in Hiscock 1986). These late-Holocene increases were often relatively dramatic compared with earlier increases. Many 1970s and 1980s explanations for these late-Holocene increases were based on the acceptance or assumption that, after an initial dramatic increase, the indices continued to increase until British colonisation. However, several researchers documented decreases in the rates of artefact accumulation at individual sites (e.g., Schrire 1972; Stockton and Holland 1974; Johnson 1979: 94, 111; Kohen et al. 1981; Moore 1981; Smith 1982; Ferguson 1985; Morwood 1986, 1987; Hiscock 1984, 1988b), while Hiscock (1986) claimed a decline in site numbers as well as in artefact discard rates. Hughes and Lampert (1982) acknowledged decreased implement accumulation rates in the last 1000 to 2000 years at some sites on the NSW south coast, but their conclusions suggest they assumed the general regional or continent-wide pattern was for implement accumulation rates, and thus population size, to continue increasing. Most researchers who identified a decrease in the indices put forward various interpretations and explanations, but general population decrease, as opposed to redistribution of populations at a local or regional level, was not advocated.terra australis 21 12
