REPRODUCTIVE STRATEGIES IN 2 ARCTIC PEDICULARIS SPECIES (SCROPHULARIACEAE)

A study of a number of reproductive traits in two sympatric species of Pedicularis in northern Swedish Lapland, the subarctic-alpine P. lapp onica and the artic P. hirsuta, revealed that the life-history strateg ies of the two species differ profoundly. High fruit set and low seed abortion rate, as in P. hirsuta, is common in arctic plants in late-th awing habitats and represents a case of extreme adversity selection ra ther than an indication of a ruderal life-history strategy. Pediculari s lapponica, on the other hand, is a typical K-strategist (or stress-t olerator) requiring a longer period of growth for optimal reproduction . Occurring at both low and high altitudes in the area, P. lapponica t ends to increase in self-compatibility with altitude, which is interpr eted as an adaptation to lower pollinator visitation frequency in arct ic environments. The variation in length of the protruding part of the style in P. lapponica is shown to be correlated with exposure to ligh t. Predispersal seed predation is severe in P. lapponica at low altitu des, where the capsules are attacked by fly and moth larvae. At high a ltitudes, a minor proportion of the capsules of P. lapponica experienc e predation and only from flies, while P. hirsuta is completely unpred ated.