Friday, July 23, 2010

Amazing Trees! The West


Back in October, 2009, I introduced the basics about studying trees. The next few entries will highlight some of our countries most amazing trees.


1. Bristlecone Pine
There are three types of Bristlecone pines, named after the spiny bristles on the trees cones. They live in the mountains of the southwestern United States, including Arizona, California, Colorado, Nevada, New Mexico, and Utah. Pinus longaeva, the Great Basin Bristlecone Pine, is thought to be the longest living single organism in the world, up to 5,000 years old! Methuselah, the oldest known bristlecone pine, is over 4,800 years old. Its location in the Ancient Bristlecone Pine Forest in California is kept secret to protect it from vandalism. The wood of the Bristlecone Pine tree is so durable, that one dead bristlecone that still stands, was alive over 10, 000 years ago!
2. Giant Sequoia and Coastal Redwood
Sequoia and Redwoods are evergreen trees that are thought to be the largest trees on earth. They are native to northern California.
At any given time, a large tree may be expected to have approximately 11,000 cones.
General Sherman is the name of a Giant Sequoia (Sequoiadendron giganteum) with a height of 275 feet (83.8 metres), and thought to be the largest tree, by volume of wood, in the US. The tree is located in the Giant Forest of Sequoia National Park in California. The tree is believed to be between 2,300 and 2,700 years old.
The current tallest tree is a Coastal Redwood (Sequoia sempervirens) named Hyperion, measuring at 115.61 m (379.3 feet). The tree was discovered in Redwood National Park during Summer 2006 by Chris Atkins and Michael Taylor and has been measured as the world's tallest living organism.
Children are fascinated by trees, and these trees are most fascinating! There are many resources about these amazing trees (See National and State Park links above):
2. A Day in the Ancient Bristlecone Pine Forest, Mark A. Schlenz. 2008. Companion Press.
3. Giant Sequoia Trees (Early Bird Nature Books), Ginger Wadsworth and Frank Staub. 1995. Lerner Publications.

Thursday, July 8, 2010

Sea Stars


Commonly called 'starfish', sea stars are not fish, but rather invertebrates belonging to a group of animals called echinoderms, which means "spiny skin." They are related to brittle stars, sea urchins, sea cucumbers, and sand dollars. Sea stars come in many colors and sizes, living in all the world's oceans, over 2000 species in all. If you live near a place where sea stars live near the shore, it's relatively easy to set up a salt water tank in your classroom to watch them for a few days.


Sea Star facts:
  • Sea stars have no brains and no blood. Their nervous system is spread through their arms and their “blood” is actually filtered sea water.

  • The five-arm varieties are the most common, hence their name, but species with 10, 20, and even 40 arms exist.

  • Sea stars use suction in the tube feet for movement and feeding. They wrap their bodies around quahogs and other bivalves, using the suction from their tube feet to pull shells apart.

  • When the prey is opened, the sea star pushes its stomach out of its body and into the bivalve, secreting enzymes that digest the prey's soft body tissues. The liquefied bivalve is then absorbed into the stomach.

  • When a sea star loses an arm, it can grow back.

Sea Star Resources:

  1. http://animals.nationalgeographic.com/animals/invertebrates/starfish.html National Geographic site about starfish, with photographs, facts, and video-clips.

  2. http://www.youtube.com/watch?v=uL2Qh4yIzzc You Tube video of a sea star moving on a glass aquarium wall.

  3. http://library.thinkquest.org/J001418/star.html Excellent Sea Star fact site.

  4. Starfish (Let's-Read-and-Find... Science) by Edith Thacher Hurd and Robin Brickman, Collins; Revised edition (May 3, 2000) .