title: Strong upslope shifts in Chimborazo's vegetation over two centuries since Humboldt.
abstract: Global climate change is driving species poleward and upward in high-latitude regions, but the extent to which the biodiverse tropics are similarly affected is poorly known due to a scarcity of historical records. In 1802, Alexander von Humboldt ascended the Chimborazo volcano in Ecuador. He recorded the distribution of plant species and vegetation zones along its slopes and in surrounding parts of the Andes. We revisited Chimborazo in 2012, precisely 210 y after Humboldt's expedition. We documented upward shifts in the distribution of vegetation zones as well as increases in maximum elevation limits of individual plant taxa of >500 m on average. These range shifts are consistent with increased temperatures and glacier retreat on Chimborazo since Humboldt's study. Our findings provide evidence that global warming is strongly reshaping tropical plant distributions, consistent with Humboldt's proposal that climate is the primary control on the altitudinal distribution of vegetation.
authors.affiliation: Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, DK-8000 Aarhus C, Denmark; Department of Integrative Biology, University of California, Berkeley, CA 94720; morueta-holme@berkeley.edu.
authors.forename: Naia
authors.identifier: http://orcid.org/0000-0002-0776-4092
authors.initials: N
authors.lastname: Morueta-Holme
authors.affiliation: Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, DK-8000 Aarhus C, Denmark;
authors.forename: Kristine
authors.initials: K
authors.lastname: Engemann
authors.affiliation: Escuela de Ciencias Biológicas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador;
authors.forename: Pablo
authors.initials: P
authors.lastname: Sandoval-Acuña
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721; Department of Biology and Honors Chemistry, Tucson High Magnet School, Tucson, AZ 85705;
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Jonas
authors.affiliation: Department of Biology, Stanford University, Stanford, CA 94305.
authors.forename: R Max
authors.initials: RM
authors.lastname: Segnitz
authors.affiliation: Section for Ecoinformatics and Biodiversity, Department of Bioscience, Aarhus University, DK-8000 Aarhus C, Denmark;
authors.forename: Jens-Christian
authors.initials: JC
authors.lastname: Svenning
mesh_terms: D057231:Climate Change; D017753:Ecosystem; D004484:Ecuador; D010944:Plants / Q000145:classification / Q000378:metabolism
keywords: Andes; climate change; land use change; range shifts; tropical biodiversity