We've reconstructed Melbourne's 200-year-old forests

edited by Swati Mestri , reviewed by Andrew Zinin

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Add as preferred source Have you ever wondered what your Melbourne suburb looked like before all the streets and houses?

For Melbourne's expanding outer suburbs, we have photos, satellite images and living memories. But what about the city's older inner suburbs, which were built well over a century ago?

The answers can be found by piecing together some of the city's earliest European maps stored in Victoria's Public Records Office (PROV) .

These maps were created between the late 1830s and mid-1850s by colonial surveyors like Robert Hoddle, William Wedge Darke and Henry Boorn Foote, who traversed different parts of what would become metropolitan Melbourne with convict survey parties to partition land for sale to British settlers .

In doing so, they marked the course of creeks and rivers, locations of swamps, the routes of early roads and the nature of the soil.

And, luckily for our research, they also marked trees to determine the corners of lots.

There, in this 180-year-old script, is the species composition of Melbourne's original urban forest. Over the past 15 years, we've worked to reconstruct these landscapes.

And now, we have our first ecological view of 1840s Melbourne.

While this kind of reconstruction has been done across North America , this is the first time that all the pieces of this ecological puzzle have been brought together for Melbourne.

To do this, we needed not only the information in the maps but also complex mathematical modeling to extrapolate the data and determine the likely density of trees in the area.

We overlaid the PROV maps over present-day Melbourne. And the results contain some incredible detail.

The original tables and maps recorded trees by their old common names, not the species names we use now. But by taking those old names and reading them against the native vegetation still growing in Melbourne, ecologists can pin down exactly which species the surveyors saw.

"Gums" were the most common tree listed in the inner suburbs.

This term refers mainly to River Red Gums ( Eucalyptus camaldulensis ).

This species is likely familiar to most Melburnians. They are abundant along waterways and in parks across the northern and southeastern suburbs.

Our first new map shows that in 1830s Melbourne, much of Collingwood and Richmond was a floodplain covered with large River Red Gums.

The next most common tree listed is the "Box."

This term describes eucalypts with flaky or scaly bark that stays on the tree rather than coming off in ribbons.

There are a number of different species of box-type eucalypts.

But using descriptions of the soils, we can find out whether they were Yellow Box ( Eucalyptus melliodora ), Grey Box ( Eucalyptus microcarpa ) or Red Box ( Eucalyptus polyanthemos ).

Our second new map uses modeling to predict the density and composition of these 200-year-old forests.

This map shows there was a woodland or forest of Yellow Box in the low hills of the inner southeast, stretching from where Government House now sits through South Yarra to Toorak and south to Gardenvale , Brighton and Highett .

Despite their prevalence in the 1840s, today only a few Yellow Box trees remain—the majority were cut down for firewood and timber.

The few that still exist can be found at the Royal Botanic Gardens Observatory Gate entrance, in the city's southeast at Moorabbin Station and in the bayside suburb of Highett .

The early forests of eastern Melbourne, on the other hand, were denser and more diverse.

The old lists feature names like "Stringybark," which could be one of many eucalypts with thick, fibrous bark that you can pull off in long strips; "Wattle" (likely Acacia mearnsii ); and other common Acacia trees like "Blackwood" ( Acacia melanoxylon ) and "Lightwood" ( Acacia implexa ).

The "Oaks" listed on the map are not European or North American oaks ( Quercus sp ) but native Drooping Sheoaks ( Allocasuarina verticillata ).

Naturally, our reconstructed forests are more accurate for the areas with more marked trees, but this map offers our best picture yet of these ancient forests.

If we look at our first map, some of the original marked trees—otherwise known as 'witness trees'—are in curious locations.

There was a pair of large "Box" trees where The National Theatre in St. Kilda now stands, and a row of "Gums" running through the current path of the Birrarung-Yarra River between the inner-city suburbs of Cremorne and South Yarra.

Despite much searching, we couldn't find any witness trees still standing in their locations.

This is perhaps because the surveyed trees were used as markers for new roads—another pattern that emerged from our maps.

But remnant trees—which are trees that predate European colonization or have grown naturally from original forests—are still common in some areas.

Ancient River Red Gums still stand in two of Melbourne's fairly central green spaces, Kevin Bartlett Reserve and Queens Park .

Gresswell Forest in the north and Valley Conservation Reserve in the city's south both have high-quality remnant trees, which give us a glimpse into the forests that once filled the landscape.

Historically, Greater Melbourne was not only made up of forests of Gums and Box trees.

Tree density drops in the western and northern areas of our map, but they weren't empty.

These were plains of Kangaroo Grass ( Themeda triandra ), often labeled as "fine sheep pasture," that drove European colonization from Tasmania and New South Wales into Victoria .

Descriptions of these open plains in the north, including in Pascoe Vale South and Coburg , tell us these plains extended almost to where our modern city now stands.

Then there are the Forgotten Woodlands of the west. The trees listed as "Honeysuckle" i...

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