Late Quaternary dynamics of pinewoods in the Iberian Mountains

Abstract

The role of pinewoods as native forests in the Iberian Mountains, and their long-term dynamics during the last interglacial, has been intensely debated among geobotanists. This debate has resulted in several different hypotheses regarding the interpretation of the present day landscape. Recent research on Late Quaternary palaeoecological records has enabled long-term patterns of forest dynamics in the main ranges of the Iberian Peninsula to be tested, and the parallel analysis of micro- (mainly pollen) and macroremains (woods, charcoals, fruits, seeds and leaves) has enhanced the resolution of these palaeobiological records. Additional historical information has allowed a complete overview of the past vegetal landscapes to be obtained. This work summarises the available data for Iberian mountain pines during the Lateglacial and the Holocene, focussing on the mountain regions in scenarios of absence or dominance. Based on this overview, life history traits and patterns of plant dynamics during the Holocene are discussed and compared with present landscapes. In the long term, Pinus does not always respond as a serial element in succession dynamics, not even in very favourable environments for hardwoods. Processes such as incumbency or resilience, and features such as frugality and their ability to disperse, affect the persistence of pines to the present day. This is exemplified for continental mountain areas, in which the absence of anthropogenic activities could have determined the wider coverage of pinewoods seen today.