A sixteen-year record of regional and temporal variation in the fruiting of beech (Fagus sylvatica L.)

Annual production of mast by the beech is highly variable, yet thereare few long-term records of the extent of masting which might help to explain the masting phenomenon. In this 16-year study, beech mast has been sampled from 100 trees by 7-min samples collected from the ground and from low-growing branches at sites ranging from the south to the north of England, and varying from closed canopy beechwood to shelter belts, avenues and isolated trees in parks. Variation in production of viable seed is much greater from year to year than from north to south. Good masting occurred in 1980, 1982, 1984, 1990 and 1995:in these years at least one year of very bad masting normally followed. Otherwise, prediction of masting is unreliable. No full mast was found in 1981. Overall there was very little full mast in five other years, but even in these years, some sites or some trees produced an appreciable amount. All trees produced empty pericarps as well as full mast, especially on lower or shaded branches. Isolated trees produced more empty pericarps than trees in groups; this is likely to result from a lack of cross pollination. It is concluded that ground sampling for a fixed period affords a rapid and effective method of assessing masting despite the factors intervening between mast shedding andcollection. [ABSTRACT FROM AUTHOR]