POLLINATION ECOLOGY OF LABIATAE IN A PHRYGANIC (EAST MEDITERRANEAN) ECOSYSTEM

This study was conducted in a phryganic (East Mediterranean) ecosystem at Daphni, near Athens, Greece. The Labiatae, represented by ten spec ies belonging to nine genera, dominate in this ecosystem type. They fl ower from February to July. Both flowering time and nectar quantity ar e related to the species ability to tolerate intense water stress. Lab iatae are visited by 201 insect species. Of these, 43 are exclusively supported by the family and 37 are monotropous. Solitary bees (mainly Anthophoridae, Megachilidae, Halictidae) constitute 47.3% of pollinato rs. The family is important in hosting specialized bees (15 species) i n phrygana, particularly late in the flowering season. Labiatae specie s form two equally represented groups in this system; namely, the late winter-early spring (early) flowering, visited by relatively few poll inator species, and the late spring-summer (late) flowering species, v isited by numerous pollinators. This temporal distinction is accompani ed by different pollination profiles that include duration of anthesis , reward to pollinators, floral attractiveness, and flower character d ifferentiation. All of these attributes are maximized in the early flo wering period. This strategy suggests a mechanism for resource partiti oning at a time when the pollinator resource is limited and competitio n for the services of pollinators is expected to be intense. Contrary to the current theory concerning cornucopian species, the copiously re warding flowers of Labiatae in phrygana are not those abundantly servi ced by pollinators.