, Volume 34, Issue 1, pp 1–20

Le bioclimat mediterraneen: Caracteres generaux, modes de caracterisation

  • Philippe Daget


Arido-humidité Bioclimat Continentalité Méditerranéen Xéricité 


This first paper on the Mediterranean bioclimate is devoted to the definition of the mediterranean climate and to its territorial extension.

It is noted that all climatologists agree on the essential characteristic of this type of climate: the relative dryness of the summer. The author maintains the definition given by Emberger, implying an estival pluviometric minimum and a biologically dry summer.

The problem of the delimitation of the seasons and the presence of a late summer in coastal regions are discussed. A territory around the Mediterranean Sea is delimited in which the summer is the least wet season, separated by a narrow transition zone from another territory in which summer is the wettest season. The degree of dryness of the summer is maintained: Köppen's criterion for a month is dry if it receives less than 30 mm of precipitation. Gaussen's dryness criteria (P+2T), retained by Walter, and those of Emberger-Giacobbe (P/M=S), are equivalent if the maximum value of the latter is taken as 5. These criteria provide a delimitation of the extension of climates exhibiting a dry summer that is closely similar to that based on Köppen's criterion.

The simultaneous application of both types of criterion enables a characterization of the extension of the climates in which the summer is both the least wet and a biologically dry season. It appears that the Mediterranean Isoclimatic Area territory thus considered extends far wider than found by western elimatologists. However, the author stresses some agreement with eastern and Arab climatologists. This divergence may be explained by supplementary constraints added to the general definition of the Mediterranean climate: on the whole a moderate dryness and temperate conditions. It is noted how some biologically routine delimitations are erroneous, e.g. climate of the olive tree,Olea europaea, andQuercus ilex, and sclerophyllous evergreen formations. Some authors seem to reduce the mediterranean climate to a coastal azonality, whereas it has been shown that this is one of the great types of climate resulting from general atomospheric circulation.

The passage from a typical Mediterranean regime to a summer rain regime is more progressive than the study of seasonal regimes implies.

An examination of the types of Mediterranean climate in the A.I.M. follows.

Monthly precipitation regimes of part of the stations of the A.I.M. are compared and classified by application of a classification algorithm to the matrix of Kendall's rank correlation coefficients. Two large units are determined, the first comprising four groups and the second five.

Global continentality is dealt with by combination of pluvial continentalityC, expressed by Angot's ratio, which is the ratio of precipitation during the six longest months to the precipitation during the six shortest months, together with thermal continentalityK' expressed by a coefficient derived from that of Gorczinski. It is emphasized that a Mediterranean climate is marked by a pluvial continentality < 1, and a thermal continentality withK'/25 ≈C.

Thermal forms are defined in accordance with the principles of Trewartha. Aridity is considered successively from several viewpoints. The value of the pluviometric module is discussed without being adopted, as it is quite inadequate. The module of the driest month, combined with the number of dry months, gives good overall results. Characterization by “Klimadiagramm” is analysed, compared with Martonne's index, and reviewed. The method of Thornthwaite is also examined.

Finally, Giacobbe's study of arido-humidity is presented in detail; standards for interpretation are given as well as an example. An application of the analysis of the duration of the vegetative pause is given, as well as a measure of the intensity of aridity. Various applications of this method are discussed.


Arido-humidity Bio-climate Continentality Mediterranean Aridity 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. AcocksJ. 1961. Veld types of South Africa. Div. of Bot. & Plant Pathology, Dept. of Agric., Pretoria.Google Scholar
  2. AkmanY. & Ph.Daget. 1971. Quelques aspects synoptiques des climats de la Turpuie. Bull. Soc. Lang. Géogr. 5: 269–300.Google Scholar
  3. Angot, A. 1906. Etude sur le régime pluviométrique de la méditerranée. C.R. Congr. Soc. Sav.: 120–134.Google Scholar
  4. Aschmann, H. 1973. Distribution and peculiarity of mediterranean ecosystems. In: Di Castri & Mooney, pp. 11–19.Google Scholar
  5. AubrevilleA. 1949. Climats, forêts et désertification de l'Afrique tropicale. Soc. Ed. Géogr. Mar. et Col., Paris, 351 p.Google Scholar
  6. BagnoulsF. & H.Gaussen. 1953. Saison sèche et indice xérothermique. Bull. Soc. Hist. Nat. Toulouse 88: 193–239.Google Scholar
  7. BagnoulsF. & H.Gaussen. 1957. Les climats biologiques et leur classification. Ann. Géogr. 66, 355: 193–220.Google Scholar
  8. BaldyCh. 1965. Climatologie et bioclimatologie de la Tunisie Centrale. F.A.O., Rome, et Secrétariat d'Etat au plan, Tunis, 2 vol.Google Scholar
  9. BirotP. & P.Gabert. 1964a. La méditerranée et le Moyen-Orient. 1. Généralités, Péninsule ibérique, Italie. Orbis, P.U.F., Paris, 550 p.Google Scholar
  10. BirotP. & J.Dresh. 1964b. La méditerranée et le Moyen-Orient. II. La méditerranée orientale et le Moyen-Orient. Orbis, P.U.F., Paris, 540 pp.Google Scholar
  11. BerengerM. 1955. Essai d'étude météorologique du bassin méditerranéen. Mém. Météo. Nat., O.M.N., Paris, 41 p.Google Scholar
  12. BortoliL., M.Gounot & J. C.Jacquinet. 1969. Climatologie et bioclimatologie de la Tunisie septentrionale. Ann. Inst. Nat. Rech. Agron. de Tunisie 42, 1: 1–235 (annexes).Google Scholar
  13. CarterD. & J.Nather. 1966. Climatic classification for environmental biology. C. W. Thornthwate Ass. Lab. of Climatology. Elmer, N.J. Publ. in climatology 19, 4: 301.Google Scholar
  14. CriddleW. 1958. Methods of computing consumptive use of water. J. Irr. & Drainage 1507: 1–27.Google Scholar
  15. ConradV. & H.Pollak. 1962. Methods in climatology. Harvard Univ. Press, Cambridge, Mass., 456 p.Google Scholar
  16. DagetPh. 1968a. Quelques remarques sur le degré de continentalité des climats de la région holartique. C.N.R.S.-C.E.P.E., Montpellier, 12 p.Google Scholar
  17. Daget, Ph. 1968b. Etude du climat local en région de moyenne montagne. Thèse Fac. Sc. Montpellier, 186 p.Google Scholar
  18. Daget, Ph. 1971. Le quotient pluviothermique d'Emberger et l'évapotranspiration globale. Bull. Rech. Agron. Gembloux, H.S.: 87–94.Google Scholar
  19. DagetPh. 1972. La limite de l'Olivler en Turqule. Note no. 9/C, C.N.R.S.-C.E.P.E., Montpellier, 6 p.Google Scholar
  20. DagetPh. 1975a. Sur quelques coefficients utilisés dans les classifications climatiques. I. Mois secs et sécheresse estivale. Note no. 19/C, C.N.R.S.-C.E.P.E., Montpellier, 10 p.Google Scholar
  21. DagetPh. 1975b. Sur quelques coefficients utilisés dans les classifications climatiques. II. Sécheresse et nombre de jours de pluie par an. Note no. 33/C, C.N.R.S.-C.E.P.E., Montpellier, 6 p.Google Scholar
  22. DagetPh. 1975c. Sur quelques coefficients utilisés dans les classifications climatiques. IV. Climates secs dans le système de Köppen. Note no. 20/C, C.N.R.S.-C.E.P.E., Montpellier, 6 p.Google Scholar
  23. DagetPh. 1976. Bibliographie classée sur le climat méditerranéen. C.N.R.S.-C.E.P.E., Montpellier.Google Scholar
  24. Daget, Ph. 1977a. Le bioclimat méditerranéen. Analyse des formes climatiques par le système d'Emberger. Vegetatio 34: (sous presse).Google Scholar
  25. Daget, Ph. 1977b. Atlasd'aréologiepériméditerranéenne. I. Nat. Monsp., sous presse.Google Scholar
  26. DagetPh. & J. P.Michel-Villaz. 1974. Délimitation de la région méditerranéenne selon les régimes de précipitation. C.R. Symp. Israel-France. Bet-Dagan, Publ. Sp. No. 39: 3–13.Google Scholar
  27. DamagnezJ., Ch.Riou, O.deVillele & S.ElAmmani, 1963. Estimation et mesure de l'évapotranspiration potentielle en Tunisie. C.R. Ass. Gén. Ass. Int. Hydrol. Sc. de Berkeley, Gentbruge, Publ. No. 62: 98–113.Google Scholar
  28. Delanoy, H. & P. Pedelaborde. 1958. Recherches sur les types de temps et le mécanisme des pluies en Algérie. Ann. Géogr. 216–244.Google Scholar
  29. Di Castri, F. 1973. Climatological comparison between Chile and the western coast of North America. In: Di Castri & Mooney, pp. 31–36.Google Scholar
  30. DiCastriF. & H.Mooney. 1973. Mediterranean type ecosystems, origine and structure. Springer Verlag, Berlin, 405 p.Google Scholar
  31. DrudeO. 1897. Manuel de géographie botanique (trad. G. Poirault). Klincksieck, Paris.Google Scholar
  32. Dubief, J. 1959. Le climat du Sahara. Inst. Rech. Sahariennes. Algers, 2 vol.Google Scholar
  33. DurandE. & Ch.Flahault. 1886. Les limites de la région méditerranéenne en France. Bull. Soc. Bot. Fr. 33: XXIV-XXXIV.Google Scholar
  34. EmbergerL. 1941. Les limites de l'aire de la végétation méditerranéenne en France. Bull. Sc. Nat. Toulouse, 1943, 78, 3: 158–180.Google Scholar
  35. EmbergerL. 1968. Les plantes fossiles dans leurs rapports avec les végétaux vivants: Masson, Paris, 758 pp.Google Scholar
  36. EmbergerL. 1971. Travaux de botanique et d'écologie. Masson, Paris, 520 p.Google Scholar
  37. EmbergerL., H.Gaussen & W.DePhilippis. 1963. Carte bioclimatique de la zone méditerranéenne. U.N.E.S.C.O., Paris, 60 p. (annexes).Google Scholar
  38. Gaussen, H. 1954a. Théorie et elassification des climats et microclimats. VIIIe Congr. Int. Bot. Paris, pp. 125–130.Google Scholar
  39. GaussenH. 1954b. Les limites des pays méditerranéens. C.R. Congr. Int. Bot. Paris. sect. 27: 161–164.Google Scholar
  40. GaussenH. 1957. Note au sujet de l'article de M. A. Guillaume. Bull. Soc. Bot. Fr. 104: 16–17.Google Scholar
  41. Gaussen, H. 1963. Voir: Emberger et al., 1963.Google Scholar
  42. Grisebach, W. 1872. Die Vegetation der Erde nach ihre klimatischen Anordnung. Leipzig.Google Scholar
  43. Geiger, R. & W. Koppen, s.d. Klima der Erde / Climate of the Earth. J. Perthes. Darmstadt, 1 Tabl.Google Scholar
  44. GèzeB. 1959. Les sols. In: La Terre, Encyel. Pleïade, Gallimard, Paris.Google Scholar
  45. Giacobbe, A. Schema di una teoria ecologia per la classificazione delle vegetazione italiana. Nuovo Gior. Bot. It. NS 45, 2: 37-121.Google Scholar
  46. GiacobbeA. 1958. Richerche ecologiche sull'aridita nei paesi del Mediterrane occidentale. Webbia 14, 1: 81–159.Google Scholar
  47. GiacobbeA. 1959. Nouvelles recherches écologiques sur l'aridité dans les pays de la méditerranée occidentale. Nat. Monsp. 11: 7–28.Google Scholar
  48. Giacobbe, A. 1962. I caracteri mediterranei delle flora montana appenica. Itral. Forst. e. Mont. (sous presse).Google Scholar
  49. GiacobbeA. 1964. La mesure du bioclimat méditerranéen. Nat. Monsp. 16: 45–60.Google Scholar
  50. Guillaume. 1957a. La flore méditerranéenne en France. Bull. Soc. Bot. Fr. 104: 1–15; 1959, 106: 353–368.Google Scholar
  51. Guillaume. 1957b. Sur quelques problèmes de phytogéographie. Bull. Soc. Bot. Fr. 104: 539–551.Google Scholar
  52. GolvanY. & J.Rioux. 1961. Ecologie des mérions du Kurdistan iranien, relations avec l'épistémiologie de la peste rurale. Ann. Parasit. 36: 449–558.Google Scholar
  53. HisnardH. 1973. Pays et paysages méditerranéens. P.U.F., Paris, 238 p.Google Scholar
  54. KöppenW. 1918. Une nouveile elassification générale des climats. Rey. Gen. Sc. 30: 550–554.Google Scholar
  55. LauerW. 1951. Hygrische Klimate und Vegetations-zonen der Tropen mit Besonderer Berücksichtigun Ostafrikas. Erdkunde 5: 284–293.Google Scholar
  56. LeFloc'hE., G.Long, J.Poissonet & M.Godron. 1973. Végétation. In. Atlás régional Languedoc-Rousillon. Berger-Levrault. Paris. Extrait, 36 p.Google Scholar
  57. LenobleF. 1934. Sur la définition de la région méditerranénne, en géographie botanique et ses limites dans le SudÉst de la France. Bull. Soc. Bot. Fr. 81: 88–96.Google Scholar
  58. Lignon, M. 1971. Développement et croissance économique en région méditerranéenne. Bull. Rech. Agron. Gembloux H.S.: 653–678.Google Scholar
  59. Louay, A. Le climat et les arabes (en prep.).Google Scholar
  60. 1927. Traité de géographie physique. I. Notions générales, Hydrographie. A. Colin, Paris, 496 p.Google Scholar
  61. Meher-HomjiV. 1971. On the mediterranean climatic regime of West-Pakistan. Arch. Met. Geoph. Biol. B 19: 277–286.Google Scholar
  62. Méteorological Office. 1954. Tables of temperature, relative humidity and precipitation for the world. H.M.S.O., London, 5 vols.Google Scholar
  63. Meteorological Office. 1962. Weather in the Mediterranean. H.M.S.O., London, 2 vols.Google Scholar
  64. Officine Met. de Chile. 1965. Pluviometrica de chile, Fac. II. Santiago de Chile, 269 p.Google Scholar
  65. PeguyCh. P. 1970. Précis de elimatologie. Masson, Paris, 468 p.Google Scholar
  66. Perrin de Brichambault, G. & C. Wallen, 1964. Une étude d'agrométéorologie dans les zones arides et semi-arides du Proche-Orient., O.M.N. Note No. 141/TP/66, No. 56. Genève.Google Scholar
  67. & P.Rognon. 1970. Les zones tropicales arides et subtropicales. A. Colin, Paris, 487 p.Google Scholar
  68. RaunkiaerC. 1907. The life-form of plants and their bearing on geography. In: The life forms of plants and statistical plant geography. Clarendon Press, Oxford, 1934, pp. 2–104.Google Scholar
  69. RebourH. 1967. Climatologie et aridiculture. C.R.. Ac. Agric. Fr. 2: 117–126.Google Scholar
  70. RousvoalD. 1973. Etude du elimat thermique des Cévennes. Pare National des Cevennes, Florac & C.N.R.S.-C.E.P.E., Montpellier, 46 p.Google Scholar
  71. ThornthwaiteC. & J.Mather. 1957. Instructions and tables for computing potential evapotranspiration and water balance. C. W. Thornthwaite Ass. Lab. of Climatology, Elmer, N.J., Publ. in Climatology, 10, 3: 183–312.Google Scholar
  72. TrewarthaC. 1954. An introduction to climate. McGraw Hill, N. Y., 102 pp.Google Scholar
  73. TrollC. 1965. Seasonal climates of the earth. In: Landsberg et al., World maps of climatology. Springer Verlag, Berlin, pp. 15–28 (+ eartes).Google Scholar
  74. TureL. 1961. Evaluation des besoins en eau d'irrigation, évapotranspiration potentielle. Ann. Agron. 12, 1: 13–49.Google Scholar
  75. WalterH. 1957. Wie kann man den Klimatypes anschaulich darstellen? Die Umschau Wissenschaft u. Technik 24: 751–753.Google Scholar
  76. WalterH. 1968. Die Vegetation der Erde in ökophysiologischer Betrachtung. Fischer, Stuttgart, 1001 pp.Google Scholar
  77. WalterH. & H.Lieth. 1960. Klimadiagramm-Weltatlas. Fischer, Jena.Google Scholar
  78. W.M.O. 1960. Normales climatologiques (CLINO) relatives aux stations climat et climat-ship pour la période 1931–1960. W.M.O./O.M.N., Genève No. 117/TP/52, 400 pp.Google Scholar

Copyright information

© Dr. W. Junk B.V. Publishers 1977

Authors and Affiliations

  • Philippe Daget
    • 1
  1. 1.Department d'Ecologie GénéraleC.N.R.S.-C.E.P.E., L. EmbergerMontpellierFrance

Personalised recommendations