Thursday, November 12, 2015

Drought, Beetles, and Fire, Oh My!

Have you noticed any trees with browning foliage in your area? When looking up towards Sierra Outdoor School from the town of Sonora, the hillsides are dotted with brown. Sometimes this color is from deciduous leaves preparing to drop from trees like California buckeye and black oak, however this year there is significantly more brown on the hillsides. As you drive up to the school you see that the brown color is from ponderosa pine trees that have died over this summer. How did this happen? What can be done about it? Is this a fire risk?

After four successive years of drought, these trees have suffered and have been unable to respond normally to environmental stresses. One thing that can stress the trees are bark beetles. These insects lay eggs underneath the bark and the larvae feed on the wood. A healthy tree responds to a bark beetle attack by filling the hole with a thick, sticky, fluid called pitch. When the trees are under water stress, as they have been due to this drought, they cannot produce enough pitch to fill the holes and keep the bark beetles out. Once a few beetles get under the bark and into the wood, they send out a chemical that lets other beetles know there's food to be had. They also lay eggs in the phloem, the layer between the bark and sapwood. The area where groups of eggs are laid is called a gallery. This gallery tunneling damages the phloem which carries sap throughout the tree, further inhibiting their ability to fend off bark beetles and stopping the flow of energy to growing parts of the tree. These beetles can also bring in a fungus that, in addition to damage from gallery construction and feeding, also contributes to tree mortality.

 Once the tree has died and the needles are all brown, it becomes a fire hazard because it is more flammable than green, living trees. However, once the dead foliage has dropped to the ground, the standing dead tree (or snag) does not pose an increased fire risk. In fact, snags provides great habitat for a variety of birds, mammals, insects, reptiles, and amphibians. Once the snag has fallen, though, it can become fuel for future fires.

There are things we can do to protect our forests and private property. Once you’ve identified the trees and the beetles they may be susceptible to, there are some steps you can take:
1) Thin tree stands:  reduces competition for resources, keeps the healthiest trees, keeps a variety of ages of trees, hinders the chemical communication between beetles, and allows you to keep more drought tolerant species.
2) Clean up blown down trees or green slash so you don’t attract beetles to this food source.
3) Be careful not to weaken trees through injury by digging near them or removing bark.
4) Remove any trees that have beetles in them and any green material >3” in diameter or chip, bury, or burn it promptly. (Depending on the beetle species, this tactic may or may not be effective)
5) Have a professional properly apply pesticides to unaffected, susceptible, or high value trees in extended drought periods. This may help the tree(s) in the long run, but it not a guarantee.
6) Water trees during extended droughts by saturating the soil down two feet near the outer edges of branches. Careful not to over water!

Much of this information comes from a USDA pamphlet, “Bark Beetles in California Conifers”.  For assistance in managing forests on private land, contact Cal Fire. For info on insect and forest management on public lands, contact the USDA Forest Service. Here is some additional information on bark beetles.

Stay tuned for the next post to see what Sierra Outdoor School has done with our ponderosa pine die-off and how we’ve managed this forest to limit the risk of forest fires. And learn how these actions affected the Oak Fire that broke out on September 8, and came within a mile of our school.

Monday, November 2, 2015

Environment-Focused Children's Literature

“And, under the trees, I saw Brown Bar-ba-loots frisking about in their Bar-ba-loot suits as they played in the shade and ate Truffula Fruits.”

While Bar-ba-loots and Truffula Fruits only exist on the pages of The Lorax, they help illustrate some very real ecological and economic principles. Children’s storybooks provide a fun and visually tantalizing way to take abstract concepts and bring them to life through storytelling. Books can also be a great way for students to teach themselves independently. Here are some storybooks we use here at Sierra Outdoor School:

The Wolves Are Back by Jean Craighead George

This book tells the real-life story of the persecution and near-extinction of wolves in Yellowstone National Park and the subsequent ecological imbalance that occurs as a result of their absence. The story describes the wolf reintroduction program, the rise in wolf population numbers and the ecological balance that returns. The story is useful in explaining the role of apex predators, the concept of interdependence and the importance of biodiversity. The author Jean Craighead George is best known for writing the “My Side of the Mountain” trilogy.

Just a Dream by Chris Van Allsburg

The story is centered around a boy named Walter who is disconnected from the environment and careless about his decisions (he is both a litterbug and a non-recycler!). He has a dream in which he sees some of the world’s wonders like Mt. Everest and The Grand Canyon degraded by pollution and development. You’ll have to read the book to find out how his life changes when he wakes up. This story helps young readers make connections between careless choices, environmental impact, conscious choices, and a better world. 

The Giving Tree by Shel Silverstein

This story describes an apple tree and the many different resources she provides for a boy over the course of his life. The neat thing about this story is that it’s simplistic telling provides much room for interpretation and can be used to teach a wide range of concepts from the joy of giving to unconditional love. We use the story here at SOS to teach about forestry resources and mindful consumption of them.

The Lorax by Dr. Seuss

In typical Dr. Seuss fashion, he uses an imaginative cast of characters to describe a real-life issue. In this case the issue is the impact that industry and consumerism has on the environment. A man named the Onceler opens up a factory that manufactures thneeds, a panacea-like product that “everyone wants and everyone needs.” The product is made from Truffula trees which provide habitat for a variety of animals. The manufacturing of thneeds not only depletes the Truffula forest but also produces pollution like “smogulous smoke.” This story helps readers make connections between the consumption of products and the resources that it takes to produce them.