As Winter begins, the oak now enters it’s most perilous season. To survive it has stripped itself of leaves, revealing another worldly beauty. The tree needs to stay alive using almost no energy, but in this dormant state the tree must face gale force winds to sub zero temperatures.
Whilst the tree looks lifeless in Winter, oaks provide a home to invertebrates ranging from spiders and wood lice, to bats and owls. The bark of the tree is an effective insulator in keeping the tree and it’s inhabitants warm. The bark is like a thick blanket, but with temperatures dropping below -10 degrees, in this condition the bark is not enough. Because water expands as it freezes and the oak could freeze solid in Winter causing catastrophic damage, it has an additional strategy. In the lead up to Winter it withdraws some of the fluid from it’s cells – it dehydrates itself. The liquid which is left contains high concentrations of sugars that act as a kind of anti-freeze.
In Winter the large spread of it’s branches helps to dissipate the gale force winds. As the oak grows it makes large amounts of new wood in the Spring followed by a smaller amount of denser wood later in the year. This rapid then slow growth gives the appearance of rings when the trunk is exposed across it’s girth – the number of rings determines the age of the tree. The Winter winds buffeting the tree produce a resistance from the timber allowing the oak to builds it’s strength year on year. It is this integral strength and durability which was harnessed to create the great Medieval buildings of the past. Salisbury cathedral for example has a spire created from timbers felled in England in 1222, which are still structurally sound today.