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Bumper autumn for forest fruits expected as nature puts on a rare show

4 September 2013

Visitors to woods and forests are in for a spectacular show of forest fruits this autumn, with the season looking like a bumper year for the fruits and seeds of many trees and shrubs, according to the Director of the Forestry Commission’s National Arboretum at Westonbirt.

Hawthorn berriesEarly signs are that ash, English oak, field maple, beech, hawthorn, hornbeam and small-leaved-lime trees will produce large crops, laden with seeds, fruits and nuts, all because of one of nature’s mysterious events known as ‘masting’.
Bumper seed years are known as ‘mast years’; a natural phenomenon where some tree species produce very large crops of seeds in some years, compared to almost none in others. 

It’s not known exactly why mast years occur, however they have been linked to various causes over the years, including weather and climatic conditions.

Simon Toomer, Director of the Forestry Commission’s National Arboretum at Westonbirt commented:

“Part of the fascination of experiencing a mast year is that we don’t completely understand the complex blend of factors that give rise to them and allow plants to coordinate the production of so much fruit and seed.

“Weather and climate can certainly affect fruit and seed production in plants, however we also see certain trees go through cycles of mast years. Beech for example produces a mast year every five to 10 years.”

With such an abundance of food available, seed-eating animals and birds, such as grey squirrels and jays, are expected to take advantage of the bounty to hoard supplies for later in the winter.

Seed-eating animal populations drop during non-mast years. As a result, in a mast year there are far more seeds than the population of predators can eat. This in turn means that more seeds will survive to next spring and germinate.

With so much food available, wildlife that feed on forest fruits are more likely to survive the winter in comparison to non-mast years and breed the following  spring, indicating that the populations of seed-eating wildlife are likely to peak next summer. 

Matthew Parratt, a scientist at Forest Research, the research agency of the Forestry Commission, said:

“This year our forests, woodlands and back gardens will put on quite a show with a number of our trees producing abundant levels of fruit and nuts.

“During non-mast years fruits, seeds and nuts are still produced, but not in these quantities, so it really will be a strong year for our harvest and wildlife.

“This occurrence is a great opportunity to experience nature at its best and with so much food you’re likely to spot more wildlife around the trees, so it’s a prime time to get out with the family and explore our woodland.”

The Forestry Commission has produced a spotter’s guide to trees and their fruits this autumn to help their woodland visitors identify fruits and seeds. Events, fungi forays and guided walks are just some of the autumn events visitors can also join in with this season.

For the fruit spotter’s guide and information about events and exploring Forestry Commission managed woods and forests this autumn, visit


Image credit. Hawthorn berries. Credit Forestry Commission/ Isobel Cameron.

For more information please contact Gina Mills, Communications Manager: or 01666 881231

Last updated: 8th August 2016

England's Woods and Forests are cared for by Forest Enterprise England, an agency of the Forestry Commission.