Origin of specimens

The oribatid mite collection of Prof. J.-C. Lions (general registration number: 28,844) was gathered in the framework of a Ph. D. thesis (Lions, 1972) defended at the University of Provence in Marseilles, France.

Mites were collected mainly from 1967 to 1970 in a calcareous massif of Jurassic and Cretaceous ages located in Lower Provence about 25 km east of Marseille, namely the massif of Sainte-Baume. The massif is characterized by a rocky crest 12 kilometers long with an East-West orientation. In fact, the crest corresponds to upper, eroded layers of a large syncline which has folded down to the North (cf. Corroy, 1939, for details). Mites inhabiting the central part of the massif, namely the Domanial Forest, have been much more intensively studied than in other places.

This Domanial Forest consists of two main types of vegetation (Molinier, 1951, 1952), namely an oak forest relating to the Quercion series and a beech forest of the Fagion series. Both oak and beech forests grow on inverted, upper and inner layers of the syncline.
Yet a sunny variant of oak forest with service trees and limes is found on high scarps whereas beech forest and its shady variant with very dense yews extend close to the scarps and over screes covering the south zone of the syncline. In addition, beech grove as well as another variant of oak forest characterized by a dense herbaceous stratum with Brachypodium pinnatum occur on marl outcrops of Campanian age which form the hinge of the syncline.

Mediterranean climatic conditions, in which winters are warm and rainy, and summers are dry and hot, are dominant in this part of Provence. Yet yearly precipitation reaches about 1,000 mm in the Domanial Forest and its vicinity whereas it is only 400 to 600 mm on the coast. As a result, Emberger (1955) pluviometric quotient values for both the beech and oak forests are a bit above the superior limit of Humid Mediterranean Stage in Emberger’s climate classification.

References

• Corroy G., 1939. Le massif de la Sainte-Baume. Étude géologique. Bulletin du Service de la Carte Géologique de France, Paris, 41: 1-124.
• Emberger L., 1955. Une classification biogéographique des climats. Recueil des Travaux du Laboratoire de Botanique, Géologie et Zoologie de la Faculté des Sciences de l’Université de Montpellier, série Botanique, 7: 3-43.
• Lions J.-C., 1972. Écologie des Oribates (Acariens) de la Sainte-Baume (Var). Thèse de doctorat en Sciences Naturelles, Université de Provence, A.O. 7248, Centre de Documentation du CNRS (1972-05-29), 2 vol., 549 pp.
• Molinier R., 1951. La chênaie pubescente de la forêt domaniale de la Sainte-Baume (Var). Bulletin du Muséum d’Histoire naturelle de Marseille, 11: 33-55.
• Molinier R., 1952. La hêtraie de la forêt domaniale de la Sainte-Baume (Var). Bulletin du Muséum d’Histoire naturelle de Marseille, 12: 63-85.