Plants and vegetation of NW Ethiopia
Ib Friis, Natural History Museum of Denmark
Sebsebe Demissew, Addis Ababa University
Odile Weber, National Museum of Natural History, Luxembourg
Paulo van Breugel, HAS University of Applied Sciences, Netherlands
Apart from the works by Pichi Sermolli, only a few recent scholarly publications have dealt with the vegetation of the Lake Tana basin. Results of field work in church forests from the Lake Tana basin1 were analysed by Alemayehu Wassie et al. (2005), a paper by Alemnew Alelign et al. (2007) describes the forest on the Zegie Peninsula at the south-western corner of the lake, and a paper with observations from the Lake Tana Basin combined with observations from further afield resulted in the definition of ‘Intermediate evergreen Afromontane forest (IAF),’ a vegetation type intermediate between the ‘Dry’ and ‘Moist Afromontane Forest’ and including forests on the shores and islands in Lake Tana (Abiyot Berhanu et al. 2018). Less attention has been given to the open vegetation types, the woodlands, but they are included in a general analysis of the natural vegetation in the Lake Tana basin, or what remains of it (Chuangye Song et al. 2018), and are dealt with in a general work on the western woodlands of Ethiopia (Friis et al. 2022). Two papers by the botanist Oskar Sebald from Stuttgart in Germany, and written in German, report on a few localities at the southern shores of Lake Tana and the Semien (Sebald 1968, 1972), and the works by Sileshi Nemomissa & Puff (2001) and Puff & Sileshi Nemomissa (2001, 2005) have dealt with the flora of the Semien. A recent study has attempted to analyse the Afroalpine vegetation of the Semien (Getahun Tassew Melese et al. 2018). The publications are discussed in more detail in chapter 7, “Later studies…”.
Surprisingly, none of these works, with the exception of Sebald (1968, 1972) and Friis et al. (2022), draws on the large plant material and field observations from the Lake Tana Basin collected by Pichi Sermolli in 1937, and the only work resulting from the Lake Tana expedition mentioned in the standard work Taxonomic Literature (Stafleu & Cowan 1983: 252–253) is the reprint of a preliminary account of the botanical results of the Lake Tana expedition (Pichi Sermolli 1938a), while the largest work on the botanical studies from 1937, Pichi Sermolli (1951), is not cited. Virtually unknown among botanists are Pichi Sermolli’s large collections of photographs of the vegetation on the western escarpment of the Ethiopian highlands, the Lake Tana Basin and the Semien. Together with photographs taken by other members of the Lake Tana expedition they are deposited at the Società Geografico Italiana in Rome and are now made available on the home page of the society.
Born on the 24th of February, 1912, Pichi Sermolli celebrated his 25th birthday at the small town of Quonzela [Consuela, Consela] on the south-western shore of Lake Tana, collecting plants at the lake shore. Due to the fact that Pichi Sermolli’s research on the Lake Tana expedition is so relatively unknown, it is appropriate to make known both the history of the botanical collections, the collections of photographs and the publications dealing with the field work, as well as to attempt a modern analysis of the botanical collections and what they may tell us about the vegetation. It is also unfortunate that Pichi Sermolli’s valuable scientific results have not been used more in the development of science, particularly in Ethiopia, because the Italian language in which they are published is not more widely read. These results should be more widely known, and the present authors hope that this publication will help to remedy that problem. We provide commented translations of the papers that present the field observations and we analyse the updated lists of the herbarium collections. In contrast, Pichi Sermolli’s many later publications in English, mainly his work on ferns, are widely read. By reconstructing the sequence of Pichi Sermolli’s 1937 collections and databasing the species, we have localised his collecting localities as precisely as possible. By reconstructing and updating the identification of the collections made at each site, it has been possible to draw conclusions about the vegetation of the localities and compare these with both of the recent reconstructions of the natural habitats of Ethiopia, Friis et al. (2010) and Friis et al. (2022), opening up hitherto unused information. We have also connected our interpretations of the modern vegetation with Pichi Sermolli’s many photographs of landscapes, which are preserved as negatives and kept in photographic archive “Fondo Missione Dainelli al Lago Tana, lotto 501” at the Società Geografica Italiana in Rome.3 The analysis in this paper is a much extended successor to work made for a paper by Friis (2015), where initial observations were made on the importance of Pichi Sermolli’s 1937 collections. That paper was written to celebrate, on the 3rd of October, 2014, the centenary of the Tropical Herbarium in Florence (Centro Studi Erbario Tropicale), the institution which holds the most complete set of Pichi Sermolli’s collections from the Lake Tana expedition. The Tropical Herbarium in Florence was originally initiated in 1904 by Pietro Romualdo Pirotta as the Erbario Coloniale at the “La Sapienza” University in Rome, intended to house material coming from the Italian colonies of Eritrea and Somalia. But when, in 1913, a National Herbarium in Florence was planned, Pirotta, convinced of the usefulness of this initiative, accepted to move the Erbario Coloniale to Florence in 1914, in the same building as and next to the National Herbarium. The Erbario Coloniale was later renamed as Erbario Tropicale (FT), and incorporated as a centre for research, the Centro Studi Erbario Tropicale (CSET), at the University of Florence.