Exploring the impact of Andean uplift and climate on life evolution and landscape modification: From Amazonia to Patagonia

The aim of this Special Issue is to improve understanding of the uplift of the Andes and its far-reaching impact on climate and biodiversity in South America from the late Mesozoic onwards. The Andes form the backbone of the South American continent and are the world's most biodiverse mountain system (Pérez-Escobar et al., in press). This biodiversity is directly related to the spatial heterogeneity and altitudinal gradients that formed during mountain building that initiated in the Cretaceous, but was not uniform across the Andes (Boschman, 2021). Geologically, the uplift of the Andes is directly linked to subduction at the western margin of the South American plate, and deformation phases are determined by changes in plate motion, direction, and subduction style (Ramos, 2009). All this implies that the Andes were not uplifted uniformly through time, and piecing this history together requires research along the almost 9000 km long stretch from the Caribbean to Patagonia. This uplift process generated new habitats and promoted biotic isolation and diversification (Pérez-Escobar et al., in press; Hoorn et al., 2018; Perrigo et al., 2020), but also formed a dramatic topographic barrier to atmospheric circulation and caused one of the most important orographic rain shadows on Earth (Poulsen et al., 2010). Hence, the developments of massive steppes in South America (Patagonia), and even extreme hyperaridity (Atacama), are also linked to the formation of the Andes (Rech et al., 2006). This special volume was inspired by the interdisciplinary meetings that were held in 2019, in celebration of the 250th birth anniversary of Alexander von Humboldt (Becker and Faccenna, 2019; Hoorn et al., 2019, in press; Linder et al., 2019). Alexander von Humboldt (1769–1859) is best known for his contributions in geology and botany and was one of the founding fathers of the field of biogeography (Linder et al., 2019). He pioneered an integrative scientific vision in combination with a great thirst for exploration and systematic data collection (Wulf, 2016). At the turn of the 19th century, Humboldt and his French colleague Aimee Bonpland ventured into the Andes and Amazon lowlands; following from this voyage, Humboldt formulated his famous model of plant distribution across the Andean slopes in the context of geology, climate, landscape, and elevational gradient (Humboldt and Bonpland, 1806). In this volume we took examples from Humboldt's interdisciplinary approach and solicited papers from different authors who with their research covered the Andes north to south, and from Amazonia to Patagonia. The resulting compilation consists of twenty papers that cover different aspects of the geological formation of the Andes, the effects of this on landscape and drainages, but also the biotic response this generated. We also looked at the Cenozoic history and the effects of climate change across the Andes, and from Amazonia to Patagonia. Furthermore, we devoted a section of the special issue to the history of Amazonia and the extensive Pebas wetland system that once covered large parts of western Amazonia. We conclude with a paper that models past climate and evaluates the effects of climate change on rainforest growth with implications for future scenarios of global warming. Below we present a summary of the content of the papers and how they each contribute to the field.