**1. Introduction**

Present-day Mediterranean vegetation is the result of the interaction of several factors and processes including past glaciation, location of refuge areas, biogeographic barriers and from the middle Holocene onwards, also anthropogenic influence [1–3].

During the Pleistocene, the advance and retreat of the ice sheets, due to climatic oscillations, had severe impacts on the distributions of many animal and plant species, which were able to survive only in suitable unglaciated habitat available during at least part of the ice ages [4].

These climate refugia have a major role in explaining modern patterns of biodiversity and species distribution [5].

As a general rule, the Iberian, Italian and Balkan peninsulas, which remained relatively ice-free and probably supported relict soils [6], have been identified as the main glacial tree refugia areas in Europe [7,8].

The location of refuge areas and the patterns of the northward spread of deciduous species during the Pleistocene–Holocene transition has been approached with many different methodologies, such as phylogeography, fossil records and Ecological Niche Models (ENMs) [5]. These synergistic approaches are being increasingly used in a combination, but to date, the studies carried out lack geographical precision in seeking to pinpoint the location of such refugia [5,9–13]. In this context, fossil records provide the best evidence for the presence of a species within a slice of both space and time. Among them, if on the one hand, palynology has long been the main technique used for paleobotanical studies [5], on the other hand, charcoal analysis has been less widely applied [10].

Charcoal analysis (anthracology) is especially suitable in the Mediterranean region where conservative environments for pollen, limited to acid and poorly aerated peat bogs and lakes, are scarce [10,14]. Although charcoals are not deposited in a continuous way, unlike pollen grains, they can provide a higher spatial resolution than pollen, because charcoals are not carried by the wind over long distances. Thus, charcoal data provide information at a local spatial scale since they testify for the local presence of the tree taxon from which they originate [10]. Unfortunately, the accuracy of paleoecological analysis, both for charcoal and pollen, is affected by inherent limitations due to the fact that taxonomic identification is not always reliable to the species level [15].

In the context of paleobiology, ENMs are being increasingly used to complement fossil and genetic evidence in biogeographical or paleontological reconstructions [16–19]. Such tools may provide an in-depth understanding of temporal changes in species distributions and their interactions with past environments. The increasing development and availability of paleoclimate data [20,21] have improved both temporal range and resolution of ENM applications, which may add effectively to fossil and genetic analysis to clarify past distribution patterns of plants, animals or biological communities [19,22,23].

The Mediterranean basin is an outstanding biodiversity hotspot with a prominent reservoir role for plant richness [7]. In this context, human cave settlements represent an exceptional paleoenvironmental archive for fine-scale biogeographic reconstruction [24].

In this study, we estimate the extent of the last glacial forest in a coastal cave of the Cilento area (SW Italy). Scarce pollen data, available for the last glacial cycle in southern Italy, revealed a peculiar difference in taxa composition, mostly related to geographical and topographic features (i.e., latitude and elevation) of the pollen catchment area. In this region of Italy, pollen data from a marine area provided information on the last 28,000 years of vegetation dynamics [25]. This data covering both mountain and coastal belts suggested that during the last glacial cycle open landscapes dominated by steppe elements coexisted with *Pinus* and forest of mesophilous taxa such *Abies* and deciduous broadleaved *Quercus* [25]. So far, the potential distribution of *Pinus* in Europe including the Italian territory during LGM has been scarcely explored [3,26]. The two above-mentioned modelling studies showed contrasting results on the presence of *P. sylvestris in* southern Italy. In fact, Cheddaddi et al. [3]. showed that *P. sylvestris* potentially occurred in central Italy while Svenning et al. [26] reported *P. sylvestris* for several areas in southern Italy. A small wild population of *Pinus nigra* currently occurs near our study site (Mts. Picentini, Vallone della Caccia) [27] while the wild population of *P. sylvestris* are restricted to northern Italy [28]. Here, we used a combination of charcoal analysis and spatial modelling to test the hypothesis that charcoals found in our study site might actually belong to *P. nigra*.

As species identification by charcoal analysis alone is problematic due to the absence of specific diagnostic key features, this hypothesis was explored using an ENM for all the species belonging to the *P. sylvestris* type found in the study site through charcoal analyses and developing models for the LGM, assessing past potential environmental suitability for the different species [15].
