Concept · Ch 11
Clearance and fragmentation (the great clearing)
Adelaide cleared its richest, flattest, easiest ground first, and cleared it almost completely — leaving the native vegetation of the plains down to a few surviving percent, scattered into patches too small and too far apart for many species to move between.
Stand anywhere on the flat built-up apron between the hills and the gulf and try to picture what stood there before 1836.
You cannot, and that is the point of this entry: the Adelaide Plains carried the richest, easiest, most fertile country in the whole gulf-to-range transect, and precisely because of that, it was cleared first and cleared almost completely.
There was no single event to mark it, no fire or flood — just decades of fence, furrow and subdivision turning open grassy woodland into farm and then city.
The result is as near total erasure as an ecosystem can suffer and still technically persist: something like four per cent of the Adelaide Plains’ original native vegetation survives today (Bradshaw 2012).
That we can even describe what was lost is largely the achievement of one patient reconstruction.
Darrell Kraehenbuehl spent decades reading colonial surveyors’ field notebooks, herbarium records and the handful of remnant scraps still standing, and in 1996 rebuilt, paddock by paddock, the open parkland of SA blue gum and grey box over tussock grassland that the first colonists found and prized (Kraehenbuehl 1996).
Clearance is only half the story, and the book keeps the second half — fragmentation — carefully distinct, because it uses a different arithmetic on different ground.
Climb off the plains into the Mount Lofty Ranges and the clearing was less total but the counting changes: something close to ninety per cent of the original woodland there has been cleared, altered or carved into disconnected pieces (Szabo et al. 2011).
A patch of woodland left standing is not the same as a patch of woodland saved.
Too small, too isolated, cut off from the next fragment by kilometres of paddock and road, a remnant can go on losing species for decades after the last chainsaw falls silent — not because anything more is being cut, but because what remains is too thin and too scattered to function as the country it used to be.
That is the quieter, slower half of the great clearing, and it is still being paid out today, in fragments all over the plains and the range front, each one a shrinking rehearsal of the plains’ original catastrophe.
Go deeper — the mechanism & the evidence
Clearance and fragmentation are often told as one event, but they are two separate insults with two separate arithmetics, and the book is careful to keep them apart. Clearance is the removal itself: on the Adelaide Plains, roughly 4% of the original native vegetation survives at all (Bradshaw 2012), a figure Kraehenbuehl (1996) could only establish by working backward from colonial surveyors' field notes, since almost nothing was left standing to measure directly. Fragmentation is what happens to whatever the clearing did not remove: in the Mount Lofty Ranges, close to 90% of the original woodland has been cleared, altered or cut into disconnected pieces (Szabo et al. 2011) — a different landscape, a different denominator, the same wound. Small, isolated patches lose species for reasons distinct from the initial clearing: populations too small to be resilient to a bad year, no nearby patch to recolonise from, edges exposed to weeds, foxes and drying wind. Szabo and colleagues showed this playing out in real time among Mount Lofty's woodland birds — some species already regionally extinct, more than half of what remains still declining on a trajectory set decades ago. Attribute every percentage to its own denominator; conflating "plains vegetation" with "ranges woodland" with "grassland alone" is the single easiest way to misquote this chapter.
Sources & further reading
Every claim here is traceable. Each citation links to its entry in the bibliography.
- Kraehenbuehl, D.N. (1996). Pre-European Vegetation of Adelaide: A Survey from the Gawler River to Hallett Cove. Adelaide: Nature Conservation Society of South Australia (317 pp.). https://catalogue.nla.gov.au/catalog/1474359 — The reconstruction of the Adelaide Plains' pre-1836 vegetation, built from surveyors' notes and remnant scraps precisely because almost nothing survived to walk through.
- Bradshaw, C.J.A. (2012). Little left to lose: deforestation and forest degradation in Australia since European colonization. Journal of Plant Ecology 5(1): 109–120. DOI: 10.1093/jpe/rtr038. https://doi.org/10.1093/jpe/rtr038 — The ~4% figure for native vegetation remaining on the Adelaide Plains.
- Szabo, J.K., Baxter, P.W.J., Vesk, P.A. & Possingham, H.P. (2011). Paying the extinction debt: woodland birds in the Mount Lofty Ranges, South Australia. Emu — Austral Ornithology 111(1): 59–70. DOI: 10.1071/MU09114. https://www.publish.csiro.au/mu/mu09114 — ~90% of original Mount Lofty Ranges woodland cleared, modified or fragmented — a distinct, ranges-wide denominator.
- Szabo, J.K., Baxter, P.W.J., Vesk, P.A. & Possingham, H.P. (2011). Paying the extinction debt: woodland birds in the Mount Lofty Ranges, South Australia. Emu — Austral Ornithology 111(1): 59–70. DOI: 10.1071/MU09114. https://www.publish.csiro.au/mu/mu09114 — How a fragmented Mount Lofty landscape keeps losing woodland-bird species long after the clearing itself stopped.
See it in the country
Adelaide rosellaCaring for Country todayCommon brushtail possumGreater bilby (the lost suburbanite)The Fleurieu peat swampsThe mallee emu-wrenMalleefowlSpear-grass & wallaby-grassNgarkat — the great mallee reserveReading absenceRiver red gumSouth Australian blue gumShort-beaked echidnaThe slender-billed thornbillSouthern brown bandicoot (the last of the dynasty)Superb fairy-wrenThe vanished grassy plainsWestern grey kangarooYellow-tailed black-cockatoo
Grounded in A Coast Running Out of Water. Every figure is stated once in the book's canonical facts register and cited to a published source.