Rethinking the value of historical photograph collections to the LTER network

28 Jul 2021 - 14:30

PCU PhD candidate, Gina Arena, recently wrote an enlightening article for the SAEON newsletter highlighting the value of historical photographs to the long-term ecological research (LTER) network. The article was dedicated to the late Dr Piet Roux, with the following dedication:

This article is dedicated to the late Dr Piet Roux, whose contribution to arid lands research in South Africa has been exceptional. Furthermore, his donation of historical data and photograph collections to the Plant Conservation Unit will continue to serve as irreplaceable baselines of data for ongoing study.


The article is well-placed, in the wake of the sudden loss of the historical landscape photograph collection (among others) in the fire that destroyed large portions of old buildings housing invaluable archival material on UCT's upper campus in April this year. The article makes a compelling case advocating for the increased use of repeat photography in supplementing existing long-term ecological data sets. Concluding thoughts from the article are below. Read the full article here.

"Newer machine-learning techniques (such as convolutional neural networking) are currently being applied to ground photographs to study aspects of plant phenology (such as flowering) or environmental change. Although promising, employing machine-learning techniques in repeat photography requires specialists with an expert knowledge in deep learning (a machine-learning technique used to teach computers how to perform human-like tasks), as well as more time and resources than may be currently available.

In many ways, using the tried and tested methods can yield comparably accurate results in a far shorter amount of time. However, the development of advanced techniques may well prove to be very handy for ecologists in the near future.

When used appropriately and with adequate supporting climate, fire and/or land use data, “before and after” photographs of environmental change serve as an effective science communication tool. The protocol used has been developed so that it can be easily applied by anyone who would like to use it."