A path of acorns

I took a slightly different route on today's dog walk and stumbled onto a path around the margin of a farm field that was completely covered in acorns.

Back here in July I commented on the abundance of fruit and nuts so early this year. But now I think we can definitely say that 2022 has been a mast year.

Every few years, some species of trees and shrubs produce a bumper crop of their fruits or nuts. The collective term for these fruits and nuts is 'mast', so we call this a mast year. Two of our most recognisable trees, oak and beech, fluctuate massively year on year in the amount of acorns and beech nuts they produce. Some years seem to have very little while in others, the nuts create a thick carpet beneath the trees. 

But why do trees produce bumper crops? One of the main theories for this behaviour is ‘predator satiation’. Animals like squirrels, jays, mice and badgers feed on the acorns and beech nuts. When the trees produce smaller crops for a few consecutive years they are, in effect, keeping the populations of these animals in check. But during a mast year, the trees produce more food than the animals can possibly eat. This abundance causes a boom in animal populations but, more importantly, it guarantees that some nuts and seeds will be left over to survive and grow into new trees. . 

Our last mast year was 2020 and they usually happen every 3 to 5 years. The crop following a mast year is always unusually low, as we saw in 2021. Low acorn years are worrying for wildlife, but they serve an important purpose. However, this year, the hot weather gave us a longer (but drier) growing season so we have another mast year just two years later. And with spring getting warmer and earlier every year the natural mast year cycle is being thrown off balance. 

How will this impact on wildlife in the long term? We'll have to wait and see.