A mast year for acorns.
Year after year our mighty oaks produce skinny snivelling acorns. Those that survive the jays and squirrels make a puny attempt to grow before being beaten back into the leaf litter. Every few years something different happens and the oaks simultaneously drop masses of big shiny seeds each fat with hope and determined to sprout and join the survival game. When this happens, we call it a mast year. The phenomenon is observed in other trees, notably the beech.
It is thought that mast year have evolved to give a survival benefit to the tree seeds. It takes huge amounts of energy to produce these seeds and they provide easy food for predators: squirrels will overwinter on them. If trees produced seeds equally each year, predator population would become consistently high and energy going into seed production wasted as squirrel food. If most years produce only limited seeds then predator numbers remain low and they will be taken by surprise by a mast year which produces an abundance and enables the surplus to grow.
Anecdotal information from wide ranging areas suggests this is a mast year for acorns and Nature’s Calendar a citizen science project run by the Woodland Trust is producing evidence that the phenomenon is occurring across the UK.
Whilst there is an agreed account of why this happens, there is little more than speculation to account for the coordinated acorn production across very wide regions. It is possible that ideal spring conditions maximise fertilisation of the oak flowers and protection of developing acorns. It is also possible that oaks speak to each other through air-borne chemical communicants or more likely through the mycelial connection of the wood-wide web. Strange though the notion of tree communication is, there is a great deal of evidence to demonstrate it in other contexts and it can explain how mast years occur in regions which transcend local weather patterns.
This year we need do little more than enjoy the rich acorn bounty. The keen might start the slow process of removing tannins to turn the acorns into something edible like flour or coffee. For the rest we might be best just to stuff our pockets and dribble them into the hedges as we walk through the countryside. The jays and squirrels do not need our help but it won’t harm either and the acorns that fall into the lining of our clothes will surely bring us good fortune.
Further info-
https://www.woodlandtrust.org.uk/blog/2020/10/what-is-a-mast-year/
https://www.bbc.co.uk/blogs/natureuk/entries/71dbb7a7-d7e1-4bf8-b56a-671e258fdf97