Trees During Winter

Winter can be a tough time for trees, and many varieties must shed their leaves for the cold months between fall and spring. Evergreens, on the other hand, have leaves on their branches during every season. Evergreens do lose their leaves, but not all at once like many trees that become bare; they gradually replace their leaves year round.

A very tall pine tree.

A very tall pine tree.

Trees that lose their leaves during the months of winter are called deciduous. Deciduous trees drop their leaves through a process called abscission. When it is time to shed the leaves, the trees produce a chemical called ABA, or abscisic acid, at the spot where the stem meets the leaf. The tree removes nitrogen and carbon from the leaves before they are released and stores them in the roots and inner bark. The nitrogen and carbon are stored as proteins, which will assist in the growth of new leaves the following spring. Shedding leaves helps the deciduous trees save water and energy, which would otherwise go to maintaining the leaves.

Similar to animals, trees also go into a hibernation-like state called dormancy. All of the trees natural processes slow down, including energy consumption, metabolism, and growth. Stalling growth saves lots of energy for the tree. Since the trees are not producing any food during the winter, they don’t need their leaves.

Evergreens also naturally promote the growth of other evergreens. Evergreen leafs and needles have a high carbon-nitrogen ratio, which makes the surrounding soil highly acidic. Evergreens have adapted to surviving in soil that has low nutrient levels, and low nutrient soil favors the growth of evergreens over that of deciduous trees. Additionally, the shade and shelter that evergreens create give younger evergreens a better chance to survive adversity, such as cold weather or drought.

A hemlock tree.

A hemlock tree.

Another danger to trees comes from snow and ice weighing down branches. Trees can receive damaged from having their branches pulled down from long periods of time. Certain evergreens, such as firs and spruces, have more flexible wood than other deciduous trees. This allows those trees to bend further with less of a risk of breaking.

Amazon to help failing U.S.P.S.

Photo credit to: Kevork Djansezian/Getty Images

Photo credit: Kevork Djansezian/Getty Images

Amazon.com announced plans to begin delivering packages every day of the week with the help of the United States Postal Service.

Amazon will use the government service to deliver packages to people on Sundays at regular postage rates. In the past, the Postal Service charged an extra fee for delivering packages on Sunday.

“As online shopping continues to increase, the Postal Service is very happy to offer shippers like Amazon the option of having packages delivered on Sunday,” Postmaster General Patrick R. Donahoe said in a statement. The deliveries will begin immediately in Los Angeles and New York, and pick up in other U.S. cities next year.

Unlike any other government agency, the U.S.P.S. has to pay $5.5 billion per year to a health fund for future retirees, reports The New York Times. The Postal Service has defaulted on three of their annual payments, and can attribute a majority of their debt the health fund payments. One measures taken by the U.S.P.S. to recover from the debt was an attempt to end Saturday mail delivery, which failed.

The Postal Service is planning to use part-time workers to manage Sunday deliveries rather than hiring more workers, said U.S.P.S. spokesperson Sue Brennan. The U.S.P.S. has been losing business due to increased use of the internet for communication and bill-paying, which has led to half the amount of postage being used in the past decade, The Washington Post reports