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EARTH DAY AND NATIONAL ARBOR DAY

Earth Day Network

The first Earth Day on April 22, 1970, activated 20 million Americans from all walks of life and is widely credited with launching the modern environmental movement. The passage of the landmark Clean Air ActClean Water ActEndangered Species Act and many other groundbreaking environmental laws soon followed. Growing out of the first Earth Day, Earth Day Network (EDN) works with over 22,000 partners in 192 countries to broaden, diversify and mobilize the environmental movement. More than 1 billion people now participate in Earth Day activities each year, making it the largest civic observance in the world.

All of EDN’s activities, whether greening schools or promoting green economic policies at home and abroad, inform and energize populations so they will act to secure a healthy future for themselves and their children. With its partner organizations, EDN provides civic engagement opportunities at the local, state, national and global levels. At every turn, EDN works to broaden the definition of “environment” to include all issues that affect our health, our communities and our environment, such as greening deteriorated schools, creating green jobs and investment, and promoting activism to stop air and water pollution.

Over the last 50 years, EDN has executed successful environmental campaigns on issues ranging from climate change and drinking water to voter registration and saving the whale. EDN is a recognized leader in creating civically–oriented innovative programs with partners outside of the environmental movement to tackle new challenges. Their core programs today focus on projects such as:

Click here for further information or how to get involved at a local level.

National Arbor Day

Learn more about this National Holiday, which is celebrated on April 25th, through the Arbor Day Foundation website, at this link.

The anatomy of a tree

Anatomy of a Tree

A: OUTER BARK

The tree’s protection from the outside world. Continually renewed from within, it helps keep out moisture in the rain, and prevents the tree from losing moisture when the air is dry. It insulates against cold and heat and wards off insect enemies.

B: INNER BARK (“PHLOEM”)

Pipeline through which food is passed to the rest of the tree. It lives for only a short time, then dies and turns to cork to become part of the protective outer bark.

C: CAMBIUM CELL LAYER

The growing part of the trunk. It annually produces new bark and new wood in response to hormones that pass down through the phloem with food from the leaves. These hormones, called “auxin”, stimulate growth in cells. Auxin is produced by leaf buds at the ends of branches as soon as they start growing in spring.

D: SAPWOOD

The tree’s pipeline for water moving up to the leaves. Sapwood is new wood. As newer rings of sapwood are laid down, inner cells lose their vitality and turn to heartwood.

E: HEARTWOOD

The central, supporting pillar of the tree. Although dead, it will not decay or lose strength while the outer layers are intact. A composite of hollow, needle-like cellulose fibers bound together by a chemical glue called lignin, it is in many ways as strong as steel. A piece 12” long and 1” by 2” in cross section set vertically can support a weight of twenty tons!

LEAVES make food for the treeLeaves

And this tells us much about their shapes. For example, the narrow needles of a Douglas fir can expose as much as three acres of chlorophyll surface to the sun. The lobes, leaflets and jagged edges of many broad leaves have their uses, too. They help evaporate the water used in food-building, reduce wind resistance— even provide “drip tips” to shed rain that, left standing, could decay the leaf.

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