© 2000 Blackwell Science Ltd. http://www.blackwell-science.com/ddi 29 BIODIVERSITY RESEARCH Diversity and Distributions (2000) 6, 29–44 Blackwell Science, Ltd Past distribution and ecology of the cork oak (Quercus suber) in the Iberian Peninsula: a pollen-analytical approach J. S. CARRIÓN*, I. PARRA†, C. NAVARRO* and M. MUNUERA§ *Departamento de Biología Vegetal, Facultad de Biología, Universidad de Murcia, 30100 Campus de Espinardo, Murcia, Spain; †Institut des Sciences de l’Evolution and Montpellier 34060 PL. E. Batailon, France; and §Departamento de Producción Agraria, ETS de Ingeniería Agronómica, Universidad Politecnica de Cartagena, 30203 Cartagena, Murcia, Spain. E-mail: carrion@fcu.um.es Abstract. This study presents pollen-analytical data from continental and offshore Iberian Peninsula sites that include pollen curves of Quercus suber, to provide information on the past distribution and ecology of the cork oak (Q. suber). Results centre on a new pollen record of Navarrés (Valencia, eastern Spain), which shows that the cork oak survived regionally during the Upper Pleistocene and was important during a mid-Holocene replacement of a local pine forest by Quercus-dominated communities. This phenomenon appears linked to the recurrence of fire and reinforces the value of the cork oak for reforestation programmes in fire-prone areas. In addition to Navarrés, other Late Quaternary pollen sequences (Sobrestany, Casablanca- Almenara, Padul, SU 8103, SU8113, 8057B) suggest last glacial survival of the cork oak in southern and coastal areas of the Peninsula and North Africa. Important developments also occur from the Late Glacial to the middle Holocene, not only in the west but also in the eastern Peninsula. It is suggested that, in the absence of human influence, Q. suber would develop in non-monospecific forests, sharing the arboreal stratum both with other sclerophyllous and deciduous Quercus and Pinus species. Key words. cork oak, historical biogeography, Iberian Peninsula, palaeoecology, pollen. INTRODUCTION The large gaps in the palaeoecological dataset for Iberia mean that our understanding of the history of major trees in the Mediterranean Basin is incomplete. This limitation becomes critical in the case of the cork oak (Quercus suber), since we need information on both the past distribution and ecology to establish management and con- servation strategies. In the course of recent investigations in the Late Quaternary site of Navarrés, Valencia, east- ern Spain, a well-differentiated oak pollen curve, assigned to Q. suber, was seen in phase with a mid-Holocene replacement of pine forests by sclerophyllous Quercus-dominated assemblages (Carrión & van Geel, 1999). In view of these findings, we felt encouraged to review the major continental and marine sequences close to the Iberian Peninsula that include pollen curves of Q. suber (Fig. 1). A preliminary point is to know the degree of confidence with which one can identify Q. suber in the pollen record. This paper relies on the conviction that palynological discrimination of Q. suber is often possible, and based on this assumption, our goals are to know: 1. Whether pollen-analytical data provides evid- ence of changes in the past distribution of Q. suber and how they interplay with the present distribution of this species in the Iberian Peninsula. Although cork oak forests gener- ally occur in areas of maritime influence on siliceous substrates, humans must have played a significant role in controlling the distribu- tion and abundance of Q. suber since it has