Ulrich Mahler’s Exkursionszettel exemplifies the importance of embodied tacit knowledge in the management of constructed landscapes.

Mahler is an expert on NSG Wagbachniederung, a nature reserve and birding hot-spot. Although retired from the nature protection agency, where he was responsible for the area for more than fifty years, he remains the site’s guardian. The artificial wetland, originally created through wastewater spillage from a nearby factory, is increasingly threatened by heat and water scarcity. Today it relies on an irrigation system that connects the site to a nearby flooded gravel pit. Mahler is the only person experienced enough to operate it: he knows when and for how long to switch on the pump to maintain the right water level.

Spending several hours daily on site, Mahler records his excursions – the hours of irrigation and encountered birds – on annotated maps that express the impossibility of codifying the complex management of the place.

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Johanna Just is an architect and doctoral fellow at the LUS Institute at ETH Zürich. Her work traces relationships among more-than-humans and the environment in the Upper Rhine Plain, exploring new modes of spatial representation. Currently, she is one of the guest editors of the 2024 issue of gta papers.