The concept of microrefugia is widely accepted to explain the post‐glacial colonization of continents, which led to the present‐day biotic configuration of the Earth. However, so far, microrefugia are no more than a ‘theoretical necessity’ without an appropriate biogeographical and ecological characterization. Here, a tentative definition and a classification of microrefugia, based on the existing literature, are proposed for discussion. A deeper biogeographical analysis of the concept is suggested using novel ecological models and methods, in order to develop new hypotheses to be tested with palaeoecological and molecular phylogenetic tools.

The fully vegetated summits of the table mountains that form the Guayana Highlands (GH), in northern South America, hold amazing biodiversity and endemism levels, and unique vegetation types. In spite of their present‐day healthy appearance, their biota is seriously threatened of habitat loss by upward displacement, because of the projected warming for the end of this century. Available data are still insufficient for a definite assessment, but preliminary estimations based on representative endemic vascular plant species show that roughly one‐tenth to one‐third of them would loss their habitat with the 2–4°C temperature increase predicted for the region by AD 2100. Given the underlying endemism, the eventual loss of biodiversity will be of global nature. Other mountain ranges around the world with similar characteristics of the GH, namely topographical isolation, high endemism and absence of nival stage because of the lower altitude, would be under similar unexpected risk, and should be urgently considered for conservation purposes.

An improved understanding of present-day climate variability and change relies on high-quality data sets from the past 2 millennia. Global efforts to model regional climate modes are in the process of being validated against, and integrated with, records of past vegetation change. For South America, however, the full potential of vegetation records for evaluating and improving climate models has hitherto not been sufficiently acknowledged due to an absence of information on the spatial and temporal coverage of study sites. This paper therefore serves as a guide to high-quality pollen records that capture environmental variability during the last 2 millennia. We identify 60 vegetation (pollen) records from across South America which satisfy geochronological requirements set out for climate modelling, and we discuss their sensitivity to the spatial signature of climate modes throughout the continent. Diverse patterns of vegetation response to climate change are observed, with more similar patterns of change in the lowlands and varying intensity and direction of responses in the highlands. Pollen records display local-scale responses to climate modes; thus, it is necessary to understand how vegetation–climate interactions might diverge under variable settings. We provide a qualitative translation from pollen metrics to climate variables. Additionally, pollen is an excellent indicator of human impact through time. We discuss evidence for human land use in pollen records and provide an overview considered useful for archaeological hypothesis testing and important in distinguishing natural from anthropogenically driven vegetation change. We stress the need for the palynological community to be more familiar with climate variability patterns to correctly attribute the potential causes of observed vegetation dynamics. This manuscript forms part of the wider LOng-Term multi-proxy climate REconstructions and Dynamics in South America – 2k initiative that provides the ideal framework for the integration of the various palaeoclimatic subdisciplines and palaeo-science, thereby jump-starting and fostering multidisciplinary research into environmental change on centennial and millennial timescales.