What is Tree ?

However, for all that familiarity, it can be somewhat difficult to define what makes a tree different from a shrub or other woody perennials

In 1964, after his coring tool broke and getting permission from the U.S. Forest Service, a research scientist to get an accurate age measurement cut down a Bristlecone Pine, in Great Basin National Park, since named Prometheus! It turned out the tree was over 4,950 years old making it older than the Bristlecone Pine named Methuselah, which at the time was 4,803 years old. He had not only found the oldest living thing on the planet, but he had also killed it. A cross-section of the tree is on view at the Great Basin National Parks, visitor center in California.

Trees are considered ‘green infrastructure’ rather than the ‘grey infrastructure’ of development such as pipes, buildings & roads

Though no scientific definition exists to separate trees and shrubs, a useful definition for a tree is a woody plant having one erect perennial stem (trunk) at least three inches in diameter at a point 4-1/2 feet above the ground, a definitely formed crown of foliage, and a mature height of at least 13 feet

The tree specie with the thickest bark other than a Redwood, is the Coast Douglas Fir tree. On the older trees, the bark can be 8 – 12 inches thick.

excess carbon dioxide (CO2) is building up in our atmosphere, contributing to climate change. Trees absorb CO2, removing and storing the carbon while releasing oxygen back into the air. In one year, an acre of mature trees absorbs the same amount of CO2 produced when you drive your car 26,000 miles.

Most tree roots stay in the top 18 inches of soil, but they can also grow above ground or dive a few hundred feet deep.

The world’s tallest living standing hardwood tree, is a Mountain Ash named Centurion which is located in Tasmania, Australia. It is approximately 329 foot 8 3/4 inches tall.

The tree specie that produces the largest cones is the Sugar Pine, ranging in size from 12 to 24 inches in length and 4 to 5 inches in diameter.

Green Infrastructure is assessed in economic terms, meaning public trees are worth money & often in significant amounts which may surprise us

Trees absorb odors and pollutant gases (nitrogen oxides, ammonia, sulfur dioxide and ozone) and filter particulates out of the air by trapping them on their leaves and bark.

Trees are generally at least 13 feet tall, have a trunk of at least three inches in diameter, and a defined crown. Shrubs, on the other hand, are woody plants that usually grow close to the ground and do not grow beyond 13 feet in height. They

Holding up a tree is a tall order, but it's often achieved by surprisingly shallow roots. Most trees don't have a taproot, and most tree roots lie in the top 18 inches of soil, where growing conditions tend to be best. More than half of a tree's roots usually grow in the top 6 inches of soil, but that lack of depth is offset by lateral growth: The root system of a mature oak, for example, can be hundreds of miles in length.

This definition works fine, though some trees may have more than one stem and young trees obviously don't meet the size criteria. A shrub can then be defined as a woody plant with several perennial stems that may be erect or may lay close to the ground.

The tree with the widest {diameter} tree trunk in the world is an African Baobab. Its trunk diameter is almost 49 foot, it has a circumference of 155 foot and is 72 foot tall.

Lignin is the substance found in wood that helps determine how hard the wood will be. The more Lignin present, the harder the wood and vice versa, the less present, the softer the wood.

They have multiple stems, rather than a single trunk, and no defined crown. Of course, there are many species of true trees that can be trained not to grow beyond a certain height and are kept small for ornamental purposes. This is considered the art of bonsai.

In one year an acre of mature trees can provide enough oxygen for 18 people.

Urban Planning experts believe that planting of appropriate street trees is the most effective expenditure of funds to improve an area because street trees transform a street into something beautiful

Still, tree roots vary widely based on species, soil and climate. Bald cypress grows along rivers and swamps, and some of its roots form exposed "knees" that supply air to underwater roots like a snorkel. Similar breathing tubes, called pneumatophores, are also found in the stilt roots of some mangrove trees, along with other adaptations like the ability to filter up to 90 percent of salt out of seawater.

It will usually have a height less than 13 feet and stems no more than about three inches in diameter.

The tree with the world’s greatest recorded tree circumference {girth} is the Santa Maria del Tule, an Montezuma Cypress. As the trunk of the tree is not circular in shape but in reality has a distorted and irregular shape, you can’t multiply the diameter by 3.14159 {pi} and come up with its true approximate circumference {girth} which is in excess of 160 foot. It is approximately 141 foot tall and over 2000 years old.

The bark of the Cork Oak is used to produce cork wine stoppers and flooring. The species grows in Northwest Africa and Southwest Europe with Algeria, Morocco, Portugal and Spain, manufacturing the majority of the world’s supply.

Average temperatures in Los Angeles have risen 6°F in the last 50 years as tree coverage has declined and the number of heat-absorbing roads and buildings has increased.
Trees cool the city by up to 10°F, by shading our homes and streets, breaking up urban “heat islands” and releasing water

When assessing what makes a good street most people rate highly the presence of good looking & tall street trees