Nature of the distributional boundary of Fucus serratus on the north shore of Spain

The distribution of Fucus serratus has a sharp boundary In northern S p a n F serratus dominates the m ~ d ~ n t e r t ~ d a l l e g ~ o n west of Novellana, Asturias but is absent further east In a short t r ans~ t~on zone F serratus 1s abundant within patches The causes underlying this pattern were investlgated by exper~rnental transplants of F serratus to locations In the transit~on zone and ou t s~de its normal range Plants moved outslde the normal range had slmllar growth and reproductive rates to those transplanted to the transition zone and ivith~n the zone of abundance F serratus recruited at s ~ t e s outside the normal boundary apparently from transplanted thalli Temperature affected the growth rate of embryos of F serratus in laboratory exper~rnents Though high summer temperatures may be responsible for the lack of F serratus in the inner part of the Bay of Blscay temperature alone cannot explain the observed l lm~t of distribution Other tactors such as l~mited dispersal ablllty and Interspecific compet~tion w ~ t h other macroalgae might also be important In settlng the boundary for F serratus in northern Spain