North America adopted a strident fire suppression and exclusion policy on its National Forests after the Great Fire of 1910, also known as the “Big Burn”. The firestorm razed over three million acres, obliterated several townships and killed 87 people, mostly firefighters. The fire shaped and cemented the US. Forest Service, which at the time was only a fledgling organisation.
Victoria followed a similar pathway after the disastrous 1939 bushfires and the Stretton Royal Commission.
Furthermore, by the turn of the century, European settlement and western expansion had severely disrupted traditional native American land management, hunting and burning. Like Australian Aboriginal people –
they burnt lightly and burnt often.
But the forests of western North America are now markedly different.
During the 1930s, the US Forest Service visited more than 800 fire lookouts across the Pacific Northwest to capture sweeping photographs of the landscape.
At each site, three 120-degree black-and-white images were taken using unique panoramic cameras designed by a forestry graduate from Yale, William Bushnell Osborne Jr, who worked at the Mt Hood National Forest between 1909 and 1953. He also invented the famous Osborne fire finder and a collapsible fire knapsack.
The Osbourne cameras were manufactured by Leupold-Volpel & Company in Portland Oregon and only about ten of the awkward and heavy (75 lbs – 34 kg) instruments were ever made.
The cleverly designed cameras had curved rails inside the film chamber to maintain a constant distance from the lens to the film surface to minimise distortion. A wind-up clock motor rotated the lens during each “transit” to take a sweeping 120-degree photo.
At the height of the project in 1934, six photographers – mostly forestry students from the University of Washington, or Oregon State College – were employed.
The three interlocking photos taken with the Osborne camera faced different directions and were taken at staggered intervals throughout the day to take advantage of the light and avoid shadows. The south-west view was taken at 9 am, the north view around noon, and the final south-east view at 3 pm. (remember, this is the northern hemisphere).
Many of the images were taken using infrared film to reduce the effect of atmospheric haze. A compass bearing was directly recorded onto the top of each photo.
The large (14-1/4 inch by 5-1/2 inch) contact prints were later “stitched together” to create a full circle panorama.
Reference copies of the photos were held in the US Forest Service regional office in Portland to help identify landmarks when smoke sightings were reported from lookouts, and then to despatch firefighters.
As far as I’m aware, there are no similar panoramic images taken from Australian fire lookouts, which is a pity.
Fire Ecology – “The Power of the Patch”.
The amazing collection of about 3000 images is called the Osborne Panoramas, and nearly a century later they are helping US foresters understand the impacts of modern fire management practices.
US Forest Service ecologist, Professor Paul Hessburg, arranged for a professional photographer, John Marshall, to visit and rephotograph as many lookout sites as possible in a project that took many years.
The paired photos tell an amazing story.
The forests of the Pacific Northwest had traditionally experienced regular low-intensity fires. They may have started by lightning or were deliberately lit by native Americans.
These forests once had a grassy and open understory which carried the fires and cleaned out the undergrowth of shrubs and saplings, leaving only the big, thick-barked old trees standing.
The forests were also once part of a broader mix of conifers, deciduous woodlands, open meadows and wetlands in a patchy broth of diverse habitats.
The “cross-talk” between the patches of burnt and unburnt forests, of different structures and ages, sizes and species, in combination with fuels, weather, topography and frequent low intensity fire, created an incredibly complex ecological mosaic.
And furthermore, it was this patchiness that provided some inherent protection from large mega-fires that the US now commonly experiences.
Hessburg convincingly argues that because of the absence of frequent low-intensity fires, together with the removal of larger trees through logging over the last century, the forests have now become overgrown, uniform aged and dominated by younger trees and understory shrubs. They also have tonnes of woody debris on the forest floor which presents an increased risk of dangerous mega-fires.
The debates about the future of forests and fire management, and how to protect communities, are strongly echoed here in Australia.
So why not do yourself a favour and watch this fascinating 14-minute Ted Talk by Paul Hessburg about “the power of the patch” and make up your own mind.
Paul Hessburg (2017). Why wildfires have gotten worse — and what we can do about it.
https://www.wildlandnw.net/osborne-panoramas-historic-and-modern
Victoria’s Forests & Bushfire Heritage 