On the Use of “Alpine” for High-Elevation Tropical Environments

The study of mountain ecosystems has a long tradition. This can be traced from the extensive geological surveys of Horace de Saussure in the 1800s in the European Alps (Billing 2019) to the seminal research that Humboldt performed on his trip through the Andes (Linder et al 2019; Moret et al 2019). However, the geographical distribution of the research has remained biased toward the global North and, more specifically, to the mountain ranges of Europe and North America (K€ orner 2003). This bias means that the understanding of mountains has been mostly based on temperate ranges in which the lives and ecology of organisms are tied to the marked rhythms that seasons impose on temperature, precipitation, and irradiance (but see Llamb ı and Rada 2019). The historical bias seems also to have percolated into the language that we use to describe mountain ecosystems. The adjective ‘‘alpine,’’ for example, has become a standard term to describe the high-elevation ecosystems that occupy the higher reaches of mountains, above the climatic tree line. Similarly, ‘‘tropical alpine,’’ is used to describe the ecosystems and vegetation that characterize the highelevation landscape of the Northern Andes and other tropical mountains (Hedberg and Hedberg 1979; Smith and Cleef 1988; Christmann and Oliveras 2020). However, this generalized use of ‘‘alpine’’ could result in 2 unintended outcomes. On the one hand, it might restrict the usefulness of the word ‘‘alpine’’ as a descriptor of the particular ecosystem traits and environmental characteristics of the temperate mountains that inspired the original use of the term. On the other hand, while used to describe the outstanding diversity of high-elevation ecosystems in the world, ‘‘alpine’’ might become simply synonymous with ‘‘high mountain,’’ thus failing to convey any meaningful idea of the diverse and unique environments that dominate the upper reaches of the mountains of the world. Therefore, does the term ‘‘alpine’’ accurately encompass the heterogeneous nature of all high-elevation ecosystems across the world, or does its reference to the temperate, seasonal landscape entail an ambiguous generalization? In this commentary, we examine the use of ‘‘alpine’’ as an overarching term to broadly describe high-elevation ecosystems and their species, using as an example the p aramo of the humid Northern Andes.