Landscape and firewood exploitation during the Holocene at La Garrotxa (Girona, NE Iberia)

Abstract

The aim of this work is to assess the landscape and management of firewood resources during the Holocene at La Garrotxa (Girona, NE Iberia), a middle mountain region (400-1600 m asl.) located within a volcanic area in the Pre-pyrenees. Anthracological and palynological data from archaeological sites and lacustrine and peat deposits from this area have been considered in order to carry out an approach to the landscape and the use of resources. Archaeobotanical data discussed here come from two main valleys, Vall d’en Bas and Vall del Llierca, where several archaeological sites were excavated covering the whole Holocene, from Mesolithic to Middle Ages. In addition to the diachronic objective, a comparison between the two valleys and among synchronic settlements in different historical periods has been done in order to evidence differences between areas both in environmental availability of raw material and in social management of natural resources. Palynological data allowed us to evaluate vegetation history in the area through the Holocene, which has been subject to climate fluctuations and to anthropic disturbance. In the Early Holocene, the landscape was characterised by the progressive expansion of forests started after the end of the Late Glacial, mainly dominated by conifers (pine and juniper) and deciduous trees (oak and hazel). The Holocene Climatic Optimum lead the culmination of forests expansion, with the dominance of dense oak forests, the landscape that first farming societies found in their arrival to this area. During Middle Holocene, the expansion of evergreen sclerophyllous trees and the regression of broadleaf deciduous trees are recorded, regarding to both climatic and anthropic causes. In the Late Holocene, the process of vegetal succession from broadleaf deciduous forests (oak) to Mediterranean evergreen forests (pine and evergreen oak) is consolidated. Charcoal data from 29 archaeological levels show the main resources used as firewood. Quercus sp. deciduous and Buxus sempervirens were the most important taxa during all the periods and areas. However some other taxa had certain importance in some periods and sites. The variability observed between sites is discussed regarding the availability of resources and landscape transformations recorded in the palynological data. This could explain the appearance of Quercus sp. evergreen and other Mediterranean taxa in the anthracological record at the MiddleLate Holocene. But also the archaeological features of the sites and the socio-historical processes are considered in order to understand the use of firewood. The characteristics of the occupations, functionality and duration, could determine how was organized the management of resources.