Chapter 1 - Núria BONADA

Chapter 3
When first explorers arrived into the Cape region, central Chile, California and Australia,
noted a high resemblance between these regions with the Mediterranean Basin (di Castri,
1981). However, the biogeographical concept of mediterranean biome was established a
century later by Grisebach (1872), Drude (1890) and Schimper (1898), based on the
similarities between vegetation in mediterranean areas. First comparative studies in these
med-regions derived from botanical aspects (Spetch, 1979; Specht & Rayron, 1957; Specht,
1973; Cody & Mooney, 1978) revealing a high similarity in plant morphology and structure
(Mooney and Dunn, 1970), with a sclerophyllous and evergreen vegetation (Kummerow, 1973;
Mooney, 1977, 1982; Rundel, 1988). Duration of the summer drought and the cold in winter
seem the ecological factors more likely to provide this similarity (Aschmann, 1973a; Nahal,
1981; Orshan, 1983; Miller, 1983). Both phenomena imply a continuous and predictable
natural disturbance, where the evolution took place (Stanford & Ward, 1983), and developing
plant communities with common characteristics with different names: chaparral in California,
maquia or matorral in the Mediterranean Basin, matorral in Chile, fynbos in South Africa and
health or mallee in Australia (Naveh & Whittaker, 1979). Some studies indicate that this type
of vegetation and structure is not exclusive from the mediterranean region, with some
extensions through areas with high summer rainfall in the east of Australia (Specht, 1979),
Mexico (Muller, 1939) or east Africa (Rundel, 1988).
In spite of these similarities, some differences are present because of local factors as human
impact, soil nutrients (Specht, 1979; Mooney, 1982; Specht & Moll, 1983), humidity (Beard,
1983), natural history (di Castri, 1973b) or landscape orography (Cody, 1973; Mooney, 1977;
di Castri, 1981). However, as a general rule, mediterranean regions are richer in species that
the adjacent ones (e.g., temperate or dry) (Raven 1973; Deacon, 1983), with a high endemism
rate (Cowling, 1992) and very heterogeneous in space and time in terms of community
composition and structure (di Castri, 1973, 1981).
Comparisons of floral and faunal communities between mediterranean regions are not easy
because in some cases a high number of taxa with different ages of origin coexist (di Castri &
Mooney, 1973). Despite of those difficulties, affinities in faunal communities between the med-
regions have been described in numerous studies. Most of them focused on lizards (Sage,
1973; Fuentes, 1976), birds (Cody, 1973; Herrera, 1995) or terrestrial arthropods (di Castri &
Mooney, 1973; Majer & Greenslade, 1988; Stamou, 1998), but few are performed in aquatic
arthropods, although some suggestions have been made (Gasith & Resh, 1999).
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