The fire that started on the slopes of Table Mountain on April 18 this year quickly swept through the University of Cape Town campus. The world watched in horror as the African Studies Library was burned to the ground. In the weeks that followed, volunteers waded through the waterlogged basement of the razed building to see which rare books had survived.
What few people beyond the university realised at the time is that barely 100 metres away the Department of Biological Sciences had also suffered catastrophic losses. “We’ve lost everything,” says Prof Timm Hoffman, the director of the Plant Conservation Unit (PCU), which was housed in a “highly flammable wooden turret” on the roof of the HW Pearson building.
One look at the blackened wreckage just over two months later confirms he is not exaggerating. “It’s too painful,” he says. “I was in that office for 20 years. I did my PhD in the room next door. I’ve probably spent more time in that building than I have in my own home.”
In addition to seeing all of their books, computers, scanners, microscopes and other equipment go up in smoke, the PCU’s entire collection of photographs was destroyed in the fire. The oldest photographs dated back to 1876. And these were not just any photos. “As an ecological historian, my entire discipline is based on historical photographs,” says Hoffman. “Photos are like little time machines. Each image is rich, rich, rich with information about the environment.”
By comparing then-and-now photos of the same landscape, Hoffman and his colleagues specialised in documenting how landscapes changed over time. “Comparing pics of the same landscape can tell you about the nature of the change, the extent of change and the rate of change,” he says. “We use the past to understand the present so we can make predictions about the future.”
Often their findings are not what you’d expect. For example, for much of the 20th century ecologists believed the semi-desert expanse of the Karoo was expanding into the Free State grasslands as a result of overgrazing. But the PCU’s work with repeat photography showed the opposite: the eastern Karoo has in fact become more grassy over the past 30 years as a result of an increase in rainfall and fewer animals grazing the veld.
Luckily, after joining the university in 2000, Hoffman invested in the digitisation of the photographic archive. Although he is yet to muster the courage to go through the digital databases – “I’m still grieving,” he says – he estimates that 30,000 images have been digitised and that he has at least one image for 90% of his most important sites. But only 10% of another collection of 35,000 slides had been digitised. “If we’d invested in bigger, faster scanners we could have finished by now,” he laments. “But I’m also very proud that we digitised at all. Not many ecologists are focused on digital archives. No one else has a collection like this in Africa.”