Living in extreme environments: distribution of Lyciumhumile (Solanaceae), an endemic halophyte from the Altiplano-Puna region, South America.

María Virginia Palchetti,Vanezza Morales-Fierro,Gloria E Barboza,Juan José Cantero,Andrés Moreira-Muñoz

doi:10.3897/phytokeys.185.71377

Abstract

Very few Solanaceae species are able to grow in saline soils; one of them is Lyciumhumile. This species is endemic to the Altiplano-Puna region (Central Andes, South America) where there are multiple extreme environmental conditions such as hypersaline soils. Here we present an updated description and distribution of L.humile including its new record for Bolivia at the edges of “Salar de Uyuni”, the largest salt flat in the world; we discuss its ecological role in saline environments by analyzing soil salinity and cover-abundance values of the studied sites. According to IUCN criteria, we recommend a category of Least Concern for L.humile, but the growing development of lithium mining in saline environments of the Altiplano-Puna region may potentially threaten exclusive communities.

Highlights

Lycium L. is the only member of tribe Lycieae (Atropina clade, Solanaceae; Hunziker 1977; Levin et al 2011; Särkinen et al 2013) and comprises nearly 90 woody species commonly found in arid, sub-arid and even saline environments (Bernardello 2013)
Lycium humile is identified by the prostrate or even mat-forming growth habit and very succulent leaves, and during summer, by the numerous white flowers and blackish berries, which grow almost on the soil surface
We document that L. humile is widely distributed in the Altiplano-Puna region and grows almost exclusively in saline soils

Summary

Introduction

Lycium L. is the only member of tribe Lycieae (Atropina clade, Solanaceae; Hunziker 1977; Levin et al 2011; Särkinen et al 2013) and comprises nearly 90 woody species commonly found in arid, sub-arid and even saline environments (Bernardello 2013). The Altiplano-Puna region of the Central Andes is considered a cold desert, with high elevation (3700 m average elev.), extreme temperatures (which can reach –30 °C) and daily temperature fluctuations, low and irregular precipitation (even < 50 mm per year), high evaporation and UV radiation, and low nutrient availability (Alonso 2013; Malatesta et al 2016) This region is characterized by numerous salt flats and shallow saline lakes, called salars, with very high salt concentrations (Alonso and Rojas 2020). Halophytes, like L. humile, are the only plants able to grow in these environments because they have different mechanisms that enhance root water uptake by decreasing their water potential (Palchetti et al 2020)

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