Geographic distribution of 24 Mediterranean and European forest tree species

The 24 distribution maps are a contribution to the regional project "Maximize the production of goods and services of Mediterranean forest ecosystems in the context of global changes" funded by the French Global Environmental Facility (FGEF) and coordinated by FAO-Silva Mediterranea and Plan Bleu. The maps are part of the activities of component 1 "Production of data and development of tools to support decision and management of vulnerable Mediterranean forest ecosystems affected by climate change and the ability of these forest ecosystems to adapt to global change". A total of 24 key forest tree species have been selected by the project partners for their importance for the biodiversity of the Mediterranean basin and for delivering ecosystem services to the Mediterranean forestry community. Data on the geographic distribution of the 24 species were compiled from different sources and make a distinction between locations of known distribution, presumed area of native distribution, and countries (or region within countries) of native distribution.

Details on how the maps were produced are given in a published report: N. Wazen, B. Fady (2016) Geographic distribution of 24 major tree species in the Mediterranean and their genetic resources, FAO and Plan Bleu, ISBN 978-92-5-109469-3, http://www.fao.org/3/a-i6338e.pdf

The 24 tree species are:

• Acer hyrcanum subsp. tauricolum (Boiss. & Balansa) Yalt
• Arbutus unedo L
• Cedrus atlantica (Endl.) Manetti ex Carriere
• Cedrus libani A. Rich
• Chamaerops humilis L.
• Ilex aquifolium L.
• Juniperus drupacea Labill.
• Juniperus excelsa M. Bieb.
• Juniperus oxycedrus L.
• Juniperus phoenicea L.
• Laurus nobilis L.
• Pinus brutia Ten.
• Pinus halepensis Mill.
• Pinus nigra J.F. Arnold
• Pinus pinea L.
• Pistacia lentiscus L.
• Platanus orientalis L.
• Quercus canariensis Willd.
• Quercus cerris L.
• Quercus coccifera L.
• Quercus ilex L.
• Quercus suber L.
• Taxus baccata L.
• Tetraclinis articulata (Vahl) Mast.

Updates of the maps are published on the FAO GeoNetwork at http://www.fao.org/geonetwork/srv/en/metadata.show?id=56996

Changes in the successive versions

Version 5

• A shapefile was added showing a single distribution area for each species. This distribution area was obtained by merging the different distributions areas available from the different sources. Known distribution localities were converted into a distribution area using alpha-shapes and this area was merged with the others.

Version 4

• Quercus suber, map in Bohbot et al. (2005): the polygon corresponding to the Venetian Lagoon was removed.

Version 3

• Pinus nigra, map of Bolos & Vigo (1984): polygons indicating presence in the eastern part of Corsica and the Balearic Islands were removed. Polygons indicating presence in the coastal zone of Croatia and some Greek islands were added.
• Quercus cerris, map of the Atlas Florae Europeae: points of occurrence corresponding to coastal tiles with a center that falls in the sea were displaced to the closest land locations.
• Arbutus unedo, map 39 in Quézel & Santa (1962): three small polygons corresponding to the southernmost part of the distribution were added. 
• Pinus halepensis, map 2 in Quézel & Santa (1962): the polygon corresponding to the zone K2 of the map was added.
• Pinus halepensis, map 3 in Quézel & Santa (1962): the polygons corresponding to the former georeferencing were removed. A small polygon in the southern and westernmost part of the distribution was added.

Version 2

• The “Source_Dat” field was harmonized using the “author_date_title” format for published references.
• All polygons were snapped together vertices within a small distance threshold to fix small coordinate misalignment in adjacent polygons. In addition, polygons were clipped with sea and administrative boundaries. 
• Pinus halepensis, map 3 in Quézel & Santa (1962): a new georeferencing using the Algerian chotts as additional georeferencing points was made. However, by mistake, the polygons from the old referencing were kept in the shapefile. This mistake was corrected in the subsequent version.