Output details

Expected trends and surprises in the Lateglacial and Holocene vegetation history of the Iberian Peninsula and Balearic Islands

Over the last years the number of palaeobotanical records from Iberia and Balearic Islands with chronological contextualisation has increased, allowing synthetizing the single local data into a more general framework. This synthesis aimed to understand the vegetation change patterns during the Lateglacial and Holocene taking into account the environmental heterogeneity of the area, which belongs to two biogeographical/climatic regions: the wet and cool Eurosiberian (N and NW Iberia) and the warm, with dry summers and relatively cool, wet winters Mediterranean (rest of Iberia and Balearic Islands). A classification of the records depending on how they respond to the deglaciation process which led into the Holocene warming highlights two types of behaviour: climate-sensitive records (Expected), and less sensitive records to climate change (Unexpected).

“Expected records” show a vegetation response to the Early Holocene similar to the commonest trend found in European higher latitudes, with the development of Quercus-dominated forests at the expense of pine woodlands and steppes. They are located in the Eurosiberian region, although also in the Mediterranean. But more than a few records from the Mediterranean region fail to show persistent trends correlated to the ones found in the “Expected records”. “Unexpected records” present absence of change, particular dynamics or threshold responses, emphasizing the complexity of the many environments found in a biodiversity hotspot such as Iberia.

Additionally, since the Middle Holocene, human activities (grazing, agriculture, mining, coppicing, slash-and-burn…) have played a determinant role in shaping the landscapes as we currently know. As for the Early Holocene climate forcing, human-induced changes have had unpredictable consequences for the ecosystems, and although some trends can be well-established for several territories, the timing of forest declines and expansions are spatially uneven and cannot be solely explained by current differences in physical setting, but for a spatially heterogeneous human utilization of natural resources.