Deciduous Trees
/Deciduous Trees are ones that loose their leaves in the fall and regrow them in the spring. Most of these trees are broad-leafed and produce flowers. There are some deciduous conifers, as I mentioned in the last post. There are also a few brad-leaf trees that are evergreen, such as the Madrona. However, trees are commonly divided into the Coniferous and Deciduous categories. It may be more correct to use the categories Gymnosperm, meaning cone-producing, and Angiosperm, meaning flower-producing. So, the last post was about Gymnosperm Trees and this one will be about Angiosperm Trees.
Losing leaves for the winter comes with a few benefits. Mainly it helps protect the trees from freezing and braking due to snow and freezing temperatures. Also while the broad leaves are really good at catching the sun’s energy in the summer, in the winter there is less sunlight. It would be more work and energy for the tree to try to keep the leaves alive. Instead, chemical signals in the tree cause the leaves to stop photosynthesizing, change color and detach from the branches. This process is called abscission. This word shares a root word with “scissors,” so think that the leaf is “cut” from the tree. The tree then goes dormant for the winter, only using the minimum about of energy it needs to stay alive.
The beautiful color changes that happen are due to chemicals breaking down in the leaf. The first to go is Chlorophyll, the pigment responsible for the green color in the leaf. Chlorophyll also is the pigment that absorbs the most light energy for photosynthesis, using the light energy to make sugar. When we see the orange, yellow and brown colors in leaves, this comes from a pigment called Carotenoids. Carrots, Daffodil flowers and banana peels all have this pigment as well. The reds and purples are caused by Anthocyanins. This pigment is also responsible for the color in blueberries, cherries, and plums.
Around camp the main broad-leafed deciduous trees we see are the Big Leaf Maples and the Red Alder. Remember, although the Madrona is broad-leafed it is not deciduous. Learn more here: http://www.soundviewcamp.com/nature-blog/2020/3/17/pacific-madrona
Big Leaf Maple
Big Leaf Maples (Acer macrophyllum) are big, beautiful trees that have leaves that can reach up to a foot across. Their scientific name literally means: “Maple Big Leaf.” Their trunks often look knobby and can moss often grows very thickly on the trunk and branches. The thick moss is great habitat for invertebrates and sometimes other plants are able to grow out of it, such as licorice ferns. The bright green flowers that bloom in the spring, come before the leaves start to grow. Then these flowers turn into helicopter-like seeds that spin when the wind catches then, helping spread their seeds farther. Big Leaf Maples are important shelter and food for many animals in the forest.
Red Alder
Red Alders (Alnus rubra), often grow in wetlands. It is known as a “pioneer” species because it can grow quickly in areas of the forest that have been disturbed by fire, cutting, or erosion. This can often help the soil of these areas because they have nitrogen-fixing bacteria in their roots. These bacteria not only help the alders grow but can help help other plants as they grown in too. Even through their seeds resemble cones, they are not conifers because they also produce flowers. Red alders have a relatively short lifespan for a tree, only living up to 100 years old. The “red” in this alder’s name comes from the fact that the inner bark of this tree, which can be used to make red dye.
