4-H/Youth Development - Tree survival in the winter
Source: Laurie Taylor Thomas, extension forester
We have all seen the typical winter scene in Kentucky with snow, barren trees, and open fields, but you may not realize that trees have coping mechanisms to help them survive the winter.
Deciduous trees drop their leaves in the fall and go dormant to help withstand frigid temperatures and accumulating snowfall. Fall’s shorter days signal to trees that winter is approaching and they need to slow down and stop their production of chlorophyll in the leaves and conserve those sugars back into the stem. They also drop leaves to conserve water into the trunk as the leaves result in a lot of lost water.
Leaf drop is just one sign of a tree going dormant to survive the winter. To fully go dormant, the tree must also slow or stop growth and reduce the amount of water going to their branches and roots. With less water, the sap left in the branches’ tissues becomes more like a concentrated sugar solution and keeps the tree from freezing.
Tree bark also helps deciduous trees survive winter. It provides a tight barrier which helps the tree retain water and keeps the tree safe from abrasions and physical damage.
Unlike deciduous trees, conifer trees keep their needles during the winter because their needles have less surface area and a waxy covering helps reduce water loss and keeps the tree from drying out. These trees can continue to carry out photosynthesis at or just above freezing.
The narrow crown of conifers helps reduce the amount of snow that can accumulate on the trees. While a heavy snowfall can cause problems for some conifers, many are pretty flexible and can bend to reduce branch breakage.
For more information about 4-H forestry opportunities, contact the Woodford County Extension office.