Chapter 3 - Pantepui as a dynamic biogeographical concept

Abstract

The Pantepui biogeographical province has been defined on the basis of present-day orographic and biotic features. In this chapter we ask whether Pantepui as a biogeographical unit has remained invariable through the Quaternary in spite of the glacial–interglacial cyclicity typical of this geological period. For this purpose, we split the Pantepui concept into three main components, namely the orographic, the climatic, and the biotic. The existing paleoecological evidence suggests that these three Pantepui components have been recurrently assembled and disassembled during interglacial and glacial phases, respectively. This is called here the Pantepui oscillator. Glacial climates have been dominant and are considered the norm during the Quaternary, whereas interglacials are viewed as abrupt warmings maintained by external energy inputs derived from positive feedbacks exacerbating solar forcing. As a consequence, interglacial Pantepui assembly may be viewed as an abrupt and comparatively short-lived unstable biogeographical state that is disrupted during glaciations, leading to a more stable state characterized by the disassembly of the orographic, climatic, and biotic Pantepui components. It follows that, rather than a present-day static biogeographical unit, Pantepui is a dynamic concept where biotic variations are linked to climatic peculiarities of each interglacial period, as well as species’ idiosyncratic responses, including eventual speciation and extinction events. The oscillator concept is used to forecast the potential state of Pantepui as a biogeographical unit in the near future under the global warming predicted for the end of this century.