image/svg+xml207 IX/2/2018 INTERDISCIPLINARIA ARCHAEOLOGICA NATURAL SCIENCES IN ARCHAEOLOGY homepage: http://www.iansa.eu Thematic Review The “Mediterranean Forest”: A Perspective for Vegetation History Reconstruction Marta Mariotti Lippi a , Anna Maria Mercuri b* , Bruno Foggi a a Department of Biology, University of Florence, Via La Pira 4, 50121 Florence, Italy b Laboratory of Palynology and Palaeobotany, Department of Life Sciences, University of Modena and Reggio Emilia, Viale Caduti in Guerra 127, 41121 Modena, Italy 1. Introduction “Mediterranean” and “Mediterranean Forest” are terms frequently used: either in a too generic manner or in a very specifc sense. Their meanings difer not only when used by amateurs but also when they are mentioned in scientifc papers, depending on the country, from the education and research felds of scholars. The “Mediterranean diet”, for instance, is not only an eating pattern of the countries surrounding the Mediterranean sea, but also a way of naming the “good food” prepared in several restaurants of the world. Thus, to reply to what meant by the word Mediterranean , we can reply with Braudel (1985 in Blondel et al ., 2010): “One thousand of things at a time”. Even referring to the Mediterranean Sea, the adjective “Mediterranean” encompasses several diferent concepts: it may indicate geographical location (Mediterranean Basin, also pointing to the countries bordering the sea), climate (Mediterranean climate) or botanical features (Mediterranean fora and Mediterranean vegetation). This paper focuses on the use of the term “Mediterranean” and its interpretation in environmental/palaeoenvironmental studies with a focus on the botanical/palynological approach. It is known that the current landscape of plants is a result of diferent factors, making vegetation history an important chapter of the environmental sciences. The fora and vegetation are basically the results of climatic changes that have occurred over millions of years. Further variations have been recently added in as a function of the human interference that has drawn and re-drawn the plant landscape through the development of diferent cultures during the Holocene (Mercuri and Sadori, 2014; Sadori et al. , 2013). This seems to have been particularly true for the Mediterranean Region, according to the opinion of Blondel et al. , (2010): “Nowhere else more than in the Mediterranean Region has nature moulded people so much and have people in turn so deeply infuenced landscapes”. The reason for this deep interdependence between cultures and environment is actually visible in the nature of the plant communities around the Mediterranean Basin, a geographic area which shows Volume IX ● Issue 2/2018 ● Pages 207 –218 *Corresponding author. E-mail: annamaria.mercuri@unimore.it ARTICLE INFO Article history: Received: 22 nd September 2018Accepted: 31 st December 2018 DOI: http://dx.doi.org/ 10.24916/iansa.2018.2.7 Key words: foristic studies palynologysclerophyllous Quercus speciesMeso-Mediterranean ABSTRACT Starting from the multifaceted meaning of “Mediterranean”, this thematic review wishes to reconnect the palaeobotanical with the phytogeographical approach in the reconstruction of the Mediterranean Forest of the past. The use of the term “Mediterranean” is somewhat ambiguous in its common use, and has not an unequivocal meaning in diferent research felds. In botany, geographical-foristic studies produce maps based on the distribution of the plant species; foristic-ecological studies, produce maps that deal with the distribution of the plant communities and their relationships with diferent habitats. This review reports on the diferent use of the term “Mediterranean” in geographical or foristic studies, and on the way climate and plant distributions are used to defne the Mediterranean area. The Mediterranean Forest through the palynological records is then shortly reported on. Pollen analysis may be employed to reconstruct the Mediterranean Forest of the past but a number of problems make this a difcult task: low pollen preservation, lack of diagnostic features at low taxonomical level, and low pollen production of species which form the Mediterranean Forests. Variable images of this vegetation are visible in diferent landscapes, but the Mediterranean Forest often remains a sort of “ghost forest” in pollen spectra from the Mediterranean Region.
image/svg+xmlIANSA 2018 ● IX/2 ● 207–218 Marta Mariotti Lippi, Anna Maria Mercuri, Bruno Foggi: The “Mediterranean Forest”: A Perspective for Vegetation History Reconstruction 208 a remarkable variety of topographical features, edaphic conditions, and plant communities. With regard to vegetation history, the palaeo- and archaeo-botanical studies deal with the fora and vegetation changes as evidenced in long-term chronological records. Analyses of pollen and plant macroremains from sediment strata and archaeological layers provide lists of plants that better attends to the fora rather than the vegetation, but references to plant communities are highly informative for reconstructing landscapes. Single-case studies are often limited in time and in space, whereas syntheses of several sites allow for wide-ranging reconstructions that overcome specifc local events (see, for example, Mercuri, 2014, for cultural landscapes reconstructed through pollen analyses). Local and regional studies can improve our knowledge on the cause-and-efect patterns which have determined broad palaeoenvironmental changes (sharp events or gradual transformations) under the various climate and anthropic infuences. Synthesis of the data in a coherent scheme is needed for reconstruction of the vegetation history of each region, but the many inhomogeneities in the terminology concerning various vegetation types, often being referred to in a generic or ambiguous way, is a major difculty in this task. In papers on palaeo- and archaeo-botany, the authors rarely explain to which plant community their results refer to, even if important exceptions exist ( e.g. Colombaroli et al. , 2009, focusing on the dynamics and history of fres; Piovesan et al. , 2018, studying an application for the restoration of forest ecosystems). Certainly we can say that reaching an unequivocal, conclusive defnition of the term “Mediterranean” is a hard task and is outside and not the aim of this paper. According to “Conservation International: Biodiversity Hotspots” 1 , the Mediterranean Basin is one of the hotspots of plant biodiversity (22,500 species with 52% of endemic species against more then 6000 species in other parts of Europe). Due to this wealth of biodiversity, defning the limits of the Mediterranean biogeographical area is a topic that is deeply under discussion among bio-geographers. Therefore, our main purpose is to make the reader aware of the level of this difculty and try to make less ambiguous the terminology referring to plant communities, and in particular the “Mediterranean Forest”. 2. The geographical use of “Mediterranean” referring to plant communities Recently, a catastrophic event made it quite clear that in layman’s terms “Mediterranean Forest” is used to indicate a forest of the Mediterranean Region in a very generic way. On March 2015, a terrifc storm scourged the coast of northern Tuscany. The fall of numerous trees changed the face of the Versilia coast. After this disaster, the local government ofcials decided to restore the “natural vegetation”. In their 1 Mediterranean Basin September, 2011: http://www.biodiversityhotspots.org/xp/hotspots/mediterranean/Pages/default.aspx. view, the natural, Mediterranean vegetation of the area consisted of woods dominated by umbrella pine often mixed with holly oak. The media were speaking about the “wild Mediterranean Forest”, meaning the woods that people are used to seeing in the territory. They believed those woods to be the natural vegetation of the area and in naming them used a geographical term (Mediterranean) derived from the proximity to the coast: But, are those woods the wild Mediterranean vegetation? Is merely growing near the Mediterranean Sea in itself sufcient to be some part of the “Mediterranean vegetation”? The reality is more a mosaic of several vegetation types that form parts of this so-called “wild forest”, including pine plantations dominated by Pinus pinea 2 and Pinus pinaster , that have been planted as several reforestation events since Roman times, and were then intensifed between the “600 and 800” ies (Giacomini, 1968; Mondino and Bernetti, 1998; Arrigoni, 1998), with an undergrowth of Quercus ilex , and a European vegetation consisting of deciduous trees such as Quercus robur , Alnus glutinosa , and Carpinus betulus . The geographical use of the term “Mediterranean Forest” is also present in scientifc papers belonging to research felds other than botany but concerning woodlands or bushlands of the countries facing the Mediterranean Sea ( e.g. Cosandey et al. , 2005, on experimental studies on forest hydrology). In such papers, the term “Mediterranean Forest” and “macchia” are often reported as synonyms. Indeed, they are both vegetation types dominated by evergreen and sclerophyllous species, but they largely difer in their dominating habitus/ growth forms: there is a prevalence of trees in the forest, and shrubs in the macchia (Arrigoni, 1996). The name “macchia” more properly refers to a very intricate, impenetrable plant community characterized by densely-branched, evergreen, sclerophyllous shrubs and climbing plants. 3. The use of the term “Mediterranean” in foristic studies Narrowing to botany, the specifc literature reveals great difculty in fnding an unambiguous defnition/use of the adjective “Mediterranean”. In general, two approaches can be used to describe the plant resources of a territory: the former is the geographical-foristic approach based on the local fora leading to the identifcation of phytochoria, i.e. areas with similar compositions of plant species (Takhtajan, 1986); the latter is the foristic-ecological approach based on the study of the distribution of plant communities and their relationships (Kent, 2012).Numerous maps of Italy based on the geographical-foristic approach were published during the last century (Fiori, 1923; Arrigoni, 1980, Romagnoli, 2003). They are syntheses useful for the regionalization of areas on a geographical ( i.e. large) scale. In this type of map (Figure 1), 2 Species names according to Euro+Med PlantBase (http://www.emplantbase.org/).
image/svg+xmlIANSA 2018 ● IX/2 ● 207–218 Marta Mariotti Lippi, Anna Maria Mercuri, Bruno Foggi: The “Mediterranean Forest”: A Perspective for Vegetation History Reconstruction 209 the largest part of the Italian peninsula is included in the Euro-Siberian Region while only a narrow strip along the coastline, in addition to the whole of Sicily and Sardinia, is attributed to the Mediterranean Region.The foristic-ecological approach focuses on the species that use the same local resources with diferent type of interactions, from independence to full interdependence (Kent, 2012). In Europe, phytosociological schools often employed this type of study (Gehu and Rivas-Martinez, 1981; Blasi, 2010; Biondi, 2011). It is particularly useful for studying plant communities on a local scale. The maps based on the foristic-ecological approach (Rivas-Martinez et al. , 2004, modifed for Italy by Blasi and Biondi, 2017) also limited the Mediterranean Region to the coast of the Italian peninsula, and included the hills and mountains of Calabria, Puglia, Sardinia and Sicily. The integration of both the geographical-foristic and foristic-ecological maps constitutes a valuable tool for the study of the past fora and vegetation history at the local scale (see, for example, Mariotti Lippi et al. , 2015, for the reconstruction of the vegetation surrounding Grotta Paglicci-Apulia). 4. Climate and plant distribution to defne the Mediterranean area The Mediterranean climate is a typical, temperate, bi-seasonal climate with the dry period – summer – coincident with the season of highest temperatures, and with mild, wet winters (Koppen, 1936). Climate has been used to defne the borders of the Mediterranean area. Gaussen (1954) used temperature as a single parameter; more specifcally, he considered the average temperature of the coldest month of the year – January or February – as one of the most