An Autumn Walk to Cranberry Lake
A Delight For The Eyes
© 2008 S. Pera
The season is definitely changing as we move our chilled hands inside the pockets of our jackets while enjoying a walk to Cranberry Lake*. On this cool crisp autumn morning, one of the first things we notice on our walk is the leaves of the Bigleaf maple trees have turned from green to radiant golden-yellow.
The name ‘bigleaf” is very descriptive of this deciduous tree native to Pacific Northwest. The leaves can grow up to 15 inches wide. No wonder they made such wonderful leaf forts when we were kids. The tree has thick dense limbs that can grow up to 110 feet tall and spread out 60 feet and may live up to 200 years. The bark is grayish-brown and somewhat grooved in the older trees. Moss, lichen and ferns often cover on the branches with an unkempt green mantle.
In the spring the branches of the maple don leaves that are dark green on top and a paler hue underneath. Small greenish-yellow flowers hang in clusters from the ends of twigs. During this time of year, these flowers are an important food source for honeybees, butterflies and hummingbirds. The fruit, two winged seeds called samara, also start to develop in the spring. Squirrels, chipmunks, and a variety of birds eat these seeds. Our local Black-tailed deer, who survive the winter months eating moss, lichen and dead shrubs, relish new growth twigs, young leaves and even saplings of the maple tree.
During the warm sunny days of summer, the leaves are factories where most of the food and energy necessary for the growth of the tree are produced. Chlorophyll, which gives the leaf its green color, takes energy from sunlight and transforms carbon dioxide and water into carbohydrates, such as sugars and starch. This process is called photosynthesis, it means, “putting together with light”. The tree rests in the winter and lives off energy stored during the summer months.
In the fall, the drop in temperatures and a decrease in the intensity of sunlight trigger the leaves to stop producing energy. Chlorophyll breaks down and the green pigment disappears, this allows the hidden yellow pigment to be revealed in a blaze of golden intensity. Our Bigleaf maple leaves have two pigments: green chlorophyll and yellow orange caroltenoids. Other trees and shrubs develop a third pigment, anthocyanins that show as vibrant red and purple hues.
As we move up the path the leaves that litter the ground crunch under our feet and the paired winged samara helicopter down on our hats, we marvel at the interrelationships in the forest habitat. The leaves we are enjoying today will not be wasted. They will decompose and replenish the soil with nutrients and make up part of the humus layer of the forest floor. These fallen leaves will also become food for soil organisms vital to the ecosystem of the forest.
*Cranberry Lake is located in Cama Beach State Park on Camano Island, Washington.
Written by Sheila Pera
Beach Watcher Class 2003
Published November 2008