What is Tree ?

Trees help us breathe — and not just by producing oxygen.
About half of all oxygen in the air comes from phytoplankton, but trees are a major source, too. Still, their relevance for humans' oxygen intake is a bit hazy. Various sources suggest a mature, leafy tree produces enough oxygen for two to 10 people per year, but others have countered with significantly lower estimates.

Yet even without the oxygen, trees clearly offer plenty of other benefits, from food, medicine and raw materials to shade, windbreaks and flood control. And, as MNN's Matt Hickman reported in 2016, city trees are "one of the most cost-effective methods of curbing urban air pollution levels and combating the urban heat island effect." That's a big deal, since more than 3 million people die worldwide each year from illnesses linked to air pollution. In the U.S. alone,

Trees cool the air as it passes through the leaves lowering the ambient air temperature

The shade of a tree can be up to 10 degrees cooler than in the direct sun

pollution removal by urban trees is estimated to save 850 lives per year and $6.8 billion in total health care costs.

Research by the US Department of Agriculture found that a young, healthy tree cools the air equivalent to 20 single room air-conditioners operating for 20 hours a day

There's also another notable way trees can indirectly save lives by breathing. They take in carbon dioxide, a natural part of the atmosphere that's now at dangerously high levels due to the burning of fossil fuels. Excess CO2 drives life-threatening climate change by trapping heat on Earth, but trees — especially old-growth forests — provide a valuable check on our CO2 emissions.

Strategic planting of 4 trees on your property can lower energy costs by up to 50%

There's also another notable way trees can indirectly save lives by breathing. They take in carbon dioxide, a natural part of the atmosphere that's now at dangerously high levels due to the burning of fossil fuels. Excess CO2 drives life-threatening climate change by trapping heat on Earth, but trees — especially old-growth forests — provide a valuable check on our CO2 emissions.

Trees around the property allow for windows to be opened for cooling rather than relying on air conditioning to lower the indoor temperature

Planting large deciduous trees on the western & northern sides of your property will keep your home cooler during the summer months & will let the sun warm your home in winter when they lose their leaves.

Adding one tree to an open pasture can increase its bird biodiversity from almost zero species to as high as 80.
Native trees create vital habitat for a variety of wildlife, from ubiquitous urban squirrels and songbirds to less obvious animals like bats, bees, owls, woodpeckers, flying squirrels and fireflies. Some of these guests offer direct perks for people — such as by pollinating our plants, or eating pests like mosquitoes and mice — while others bring subtler benefits just by adding to local biodiversity.

To help quantify this effect, researchers from Stanford University recently developed a way to estimate biodiversity based on tree cover. They recorded 67,737 observations of 908 plant and animal species over a 10-year period, then plotted those data against Google Earth images of tree cover. As they reported in a 2016 study, four of the six species groups — understory plants, non-flying mammals, bats and birds — saw a significant biodiversity boost in areas with more tree cover.

Trees lower heating bills by protecting the building from wind

Trees lower the temperature of footpaths & roads, which stops heat built up & deflection making cities more pleasant to live in.  This is called the Urban Heat Island Effect

They found that adding a single tree to a pasture, for example, could raise the number of bird species from near zero to 80. After this initial spike, adding trees continued to correlate with more species, but less quickly. As a stand of trees approached 100 percent coverage within a certain area, endangered and at-risk species like wildcats and deep-forest birds began to appear, the researchers report.

Street trees help buffer & deflect traffic noise thereby reducing noise pollution

Trees can lower stress, raise property values and fight crime.
It's human nature to like trees. Just looking at them can make us feel happier, less stressed and more creative. This may be partly due to biophilia, or our innate affinity for nature, but there are also other forces at work. When humans are exposed to chemicals released by trees known as phytoncides, for example, research has shown results such as reduced blood pressure, reduced anxiety, increased pain threshold and even increased expression of anti-cancer proteins.

Only a very small percentage of trees fall during severe storms

Many people develop an emotional attachment to individual or a group of trees & associate them with meaningful events within their lifetime

This is often shared with family members & other close people forming continuity between the generations

Trees can be ‘place-makers’ & whole areas can be defined & recognised by their trees

Trees can help people navigate their way around an area as they act as landmarks

Urban planners consider trees to be the most important factor in the design of urban landscapes

Trees provide visual interest within a landscape in terms of their species, height, leaf & bark colour & patterns, their shape & their sense of movement