Klaus Winter - the indefatigable CAM experimentalist

Abstract

Background: In January 1972, Klaus Winter submitted his first paper on crassulacean acid metabolism (CAM) whilst still an undergraduate student in Darmstadt. During the subsequent half-century, he passed his Staatsexamensarbeit, obtained his Dr. rer. nat. summa cum laude and Dr. rer. nat. habil., won a Heinz Maier-Leibnitz Prize and a Heisenberg Fellowship, and has occupied positions in Germany, Australia, the USA and Panama. Now a doyen in CAM circles, and a Senior Staff Scientist at the Smithsonian Tropical Research Institute (STRI), he has published over 300 articles, of which about 44 % are about CAM.

Scope: I document Winter's career, attempting to place his CAM-related scientific output and evolution in the context of factors that have influenced him as he and his science progressed from the 1970s to the 2020s.

Keywords: Mesembryanthemum crystallinum; Biography; Klaus Winter; Smithsonian Tropical Research Institute (STRI); crassulacean acid metabolism (CAM); facultative CAM; inducible CAM.

Fig. 1.

Klaus Winter perched among Mesembryanthemum plants growing on a coastal cliff near Caesarea in Israel, 1977. Photo: K. Winter.

Fig. 2.

Enjoying Nobby’s Nuts and the sunshine in the Fellows’ Garden of University House, ANU, 1978. From left to right: Olle Björkman, Otto Lange, Erika Winter, Rosemary Dunn, Joe Holtum, Jennifer Holmgren, Steve Powles, Klaus Winter and Grahame Farquhar. Photo: S. C. Wong.

Fig. 3.

Klaus Winter and epiphytes in an eastern Australian rainforest, 1978 or 1979. Photo: C. B. Osmond and C. Büchen-Osmond.

Fig. 4.

The Madison years, at the home of Gerry and Sandy Edwards, 1980. From left to right: Joyce Foster, Joe Holtum, Klaus Winter and Hitoshi Nakamoto. Photo: G. E. Edwards.

Fig. 5.

Klaus Winter in the Papua New Guinea Highlands in the vicinity of Mt Wilhelm during the 1984 Oakham School Expedition to Papua New Guinea. Photo: K. Winter.

Fig. 6.

Winter’s open-air laboratory, ‘Winterland’, the STRI Gamboa Research Station with climate-controlled domes, CO₂-controlled enclosed chambers, open-top chambers, tree-sized pots and the Clusia collection. Photo: M. Garcia.

Fig. 7.

The engine-room of the STRI Winter laboratory: Dr Aurelio Virgo in the cloud forest at Cerro Jefa, Panama (A), Milton Garcia the technical whiz (B) and Jorge Aranda processing a leaf of Tectona grandis (teak) (C). Photos: K. Winter (A and B) and M. Guerra (C).

Fig. 8.

For his first 20 years at STRI, Klaus produced hundreds of metres of chart paper to record plant gas-exchange results, all of which was patiently transcribed to digital values by hand. Photo: K. Winter.

Fig. 9.

Attendees of CAM: 2001, held amongst the rainforest of Cape Tribulation in northern Queensland, Australia. From left to right: Front row: Lonnie Guralnik, Rowan Sage and Jennifer Henry. Second tier: Stefan Arndt, Uwe Rascher, Maik Zabrowski, Hideaki Usuda, Jack and Nicholas Christopher, Mark Schöttler, Mandy and Ruby Christopher, James Hartwell, Andrew Smith, Anne Borland, Wolfgang Wanek, Jeremy Barnes, Klaus Winter, Tahar Taybi, Howard Griffiths and Jiri Santrucek. Back tier: Dieter von Willert, Fernanda Reinert, Joe Holtum, Kate Maxwell, Ulrich Lüttge, Hugh Nimmo, Bill Cockburn, Olga Cockburn and Akihira Nose. Photo: J. Henry.

Fig. 10.

Rehydrating during the 34th New Phytologist Symposium on Systems Biology and Ecology of CAM Plants, Lake Tahoe, 2014. From left to right: Erika Edwards, Joe Holtum, Andrew Smith, Howard Griffiths and Klaus Winter. Photo: R. F. Sage.

Fig. 11.

Klaus Winter, Joe Holtum and Noris Arrocha enjoying the fruits of photosynthesis and contemplating the next 50 years on a rooftop balcony during a balmy tropical evening at San Felipe, Panama City, in 2018. Photo: J. A. M. Holtum.