A sixteen-year record of regional and temporal variation in the fruiting of beech (Fagus sylvatica L.) in England (1980-;1995)

Annual production of mast by the beech is highly variable, yetthere are few long-term records of the extent of masting whichmight help to explain the masting phenomenon. In this 16-yearstudy, beech mast has been sampled from 100 trees by 7-min samplescollected from the ground and from low-growing branches at sitesranging from the south to the north of England, and varyingfrom closed canopy beechwood to shelter belts, avenues and isolatedtrees in parks. Variation in production of viable seed is much greater fromyear to year than from north to south. Good masting occurredin 1980, 1982, 1984, 1990 and 1995: in these years at leastone year of very bad masting normally followed. Otherwise, predictionof masting is unreliable. No full mast was found in 1981. Overallthere was very little full mast in five other years, but evenin these years, some sites or some trees produced an appreciableamount. All trees produced empty pericarps as well as full mast, especiallyon lower or shaded branches. Isolated trees produced more emptypericarps than trees in groups; this is likely to result froma lack of cross pollination. It is concluded that ground samplingfor a fixed period affords a rapid and effective method of assessingmasting despite the factors intervening between mast sheddingand collection.