Further to the literature review in Chapter 2 (2.1.2), several stages of landscape change from the period before digital data were available could be reconstructed and quantified from digitised paper maps.
Much of the Esk Rivers basin, the second rural settlement area in Australia after the Cumberland Plains in New South Wales, was under European settlement by 1825 (Scott, 1965). In this year the colony of Tasmania separated administratively from New South Wales (Fensham, 1989; Morgan, 1992) (Table 4.2; Figures 4.4 & 4.5).
Table 4.2: Cumulative alienation of land in the Esk Rivers basin (% catchments).
Source: Scott, (1965). Note: study basin area percentages have been calculated from digitisation of a paper map and are approximate.
Catchment (%) Macquarie Meander North Esk South Esk Brumbys-Lake Basin
1824 25 6 16 14 17 16
1854 63 31 17 37 35 41
1914 87 74 61 60 68 71
1964 90 74 63 61 72 73
By 1843, Crown land sales had replaced grants as incentives and total alienation in Tasmania reached 8,094 km2 (Lakin, 1967). Privately owned land had extended into almost all the Midlands plains of the Esk Rivers basin, the upper Derwent valley and much of the east coast (Scott, 1965; Lakin, 1967). Indeed, by 1st January 1850, privately owned land covered 11,020 km2 of Tasmania, while the area of Crown land held under depasturing (grazing) licences was 5,406 km2 (Lakin, 1967).
4 Landscape physiography of the Esk Rivers basin and change over the Holocene quantified by GIS
131 Figure 4.5: Land alienation in the Esk rivers basin to 1964. Blank areas on the map remained vested in the Crown at 1965; most of this land remains so vested today. Paper map source: Scott, 1965.
Figure 4.6: Proportion and progression of total alienated land in the Esk Rivers basin and its catchments over the period of European colonisation (km2). Source: Scott, 1965.
690
1030 670
82
Macquarie Crown Land alienation (km2)
256
264 492
53
Brumbys-Lake Crown Land alienation (km2)
98
387 679
6
Meander Crown Land alienation (km2)
165
12 476
23
North Esk Crown Land alienation (km2)
473
762 770
43
South Esk Crown Land alienation (km2)
1681
2455 3086
207
Whole basin Crown Land alienation (km2) and figure legend
1808-24 1825-54 1855-1914 1914-64
4 Landscape physiography of the Esk Rivers basin and change over the Holocene quantified by GIS
133 Permanent settlement lagged land alienation in the Midlands until after 1911 (Scott, 1965), reflecting the nature of sheep husbandry of the times, with flocks roaming freely over the large grazing runs. The Closer Settlements Acts 1906-08 allowed for division of large estates that had become regarded as underutilised (Australian Bureau of Statistics, 1910). Annual alienation reduced with availability of land in Tasmania between 1910 and 1964 and had all but ceased by 1965 (Cocking, 1985; Figures 4.5 to 4.7). On this basis, alienation of Crown land across the state was effectively complete only about 160 years after settlement, although significantly, it took decades less in the Esk Rivers basin (Figure 4.7).
Figure 4.7: Aggregated land alienation, Tasmania and Esk rivers basin. Source: Scott, (1965), Tasmanian Year Book No. 1 (Lakin, 1967) and Tasmanian Year Book 1985 (Cocking, 1985). Note: study basin areas have been calculated from digitisation of a paper map and are approximate.
Lands close to the port of Launceston as well as the open plains of the Midlands were settled both more rapidly, and ultimately more completely, than other catchments across
0 5000 10000 15000 20000 25000 30000 1800 1850 1900 1950 2000 km 2 Year Tasmania Esk Rivers basin
4 Landscape physiography of the Esk Rivers basin and change over the Holocene quantified by GIS
134
Tasmania. Only 10% of the original Crown land of the Macquarie catchment remained uncommitted by 1964 (Table 4.2). The early utilisation of the Esk Rivers basin for agricultural production, disproportionate relative to its proportion of Tasmania’s landmass, reflected its large share of land suitable and readily available for agriculture. Most of today’s private tenure in the basin was established prior to 1914 and by 1964, private ownership had reached 73% or 7,429 km2 (Figures 4.5 & 4.6). The extent of clearance of the Esk Rivers basin and remaining native vegetation at 1964 is shown in Figures 4.8 and 4.9 (below).
4 Landscape physiography of the Esk Rivers basin and change over the Holocene quantified by GIS
135 Figure 4.8: Vegetation of the Esk rivers basin in 1964. Source: Davies, 1964, in Davies, 1965. Note: “sclerophyll forest” includes grassy and shrubby woodlands; “moorland” consists of alpine vegetation.
136
Figure 4.9: Areas of native vegetation and cleared land in the Esk Rivers basin catchments at 1964 (km2). Source: Davies, 1965. Note: “sclerophyll forest” includes grassy and shrubby woodlands.
1836 885 Macquarie 1964 vegetation (km2) 109 832 89 543 Meander 1964 vegetation (km2) 288 546 11 216 North Esk 1964 vegetation (km2) 289 2292 93 336 South Esk 1964 vegetation (km2) 983 52 445 Brumbys-Lake 1964 vegetation (km2) 686 6489 245 2425
Whole basin 1964 vegetation (km2) and legend
Rainforest/mixed forest Sclerophyll forest Moorland Cleared
4 Landscape physiography of the Esk Rivers basin and change over the Holocene quantified by GIS
137
In his broad classification of vegetation, Davies (1965) included grassy and shrubby woodlands in “sclerophyll forest,” and “cleared” included a mosaic of introduced pastures and cropping land with native grassland and woodland remnants. Montane vegetation is expressed as “moorland.”
Table 4.3: Vegetation in the Esk Rivers Basin at 1964 (% catchments). Source: Davies, 1964, in Davies, 1965. Note: “sclerophyll forest” includes grassy and shrubby woodlands. Catchment (%) Macquarie Meander North Esk South Esk Brumbys-Lake Basin Rainforest/ mixed forest 0 7 27 10 0 7 Moorland 0 6 1 3 3 2 Sclerophyll forest 67 53 51 76 66 66 Cleared 33 35 20 11 30 25
At 1964, Brumby’s-Lake, Macquarie and Meander catchments had the highest proportions of cleared land, in contrast to the South and North Esk catchments where clearing was hindered by a higher proportion of heavily wooded, elevated country. It can be seen between colonisation and 1964, much agricultural country was cleared at the expense of forest cover (shown as vegetation with over 30% canopy in Pre-
European vegetation, Figure 4.3), especially the tall and medium forests in the upper Meander and Brumbys/Lake catchments, in the lowlands of the middle and upper reaches of the South Esk catchment and in Launceston’s near hinterland. Tall forest was reduced in the St Patricks River sub-catchment in the North Esk catchment. Elsewhere, grassy woodland country (less than 30% canopy in Figure 4.3) has been cleared. Nevertheless, in 1964, native vegetation still flanked the plains on the surrounding
4 Landscape physiography of the Esk Rivers basin and change over the Holocene quantified by GIS
138
hillslopes, clothing the more distal hinterlands as well as the Esk Rivers highlands (Figure 4.8).
On the other hand, in comparing the maps of Pre-European vegetation (Figure 4.3) and 1964 vegetation (Figure 4.8), sclerophyll forests and woodlands had reclaimed quite substantial parts of the Midlands, particularly in the Macquarie and South Esk
catchments. Consistent with the present review (Chapter 2), it appears likely that these incursions reveal areas of the Midlands that were previously in ecotype disclimax, having been kept in check by Aboriginal fire, in contrast to much of the Midlands that required no Aboriginal fire to maintain the ecosystems, as suggested by Fensham and Kirkpatrick (1992) (Section 2.1). These findings suggest prior to European occupation, the Midlands landscape was partly an Aboriginal cultural artefact and partly controlled by climate, browsing and conditioned exclusion of eucalypt seedlings.