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Palo Alto residents have long taken pride in their trees. In its native state, much of the area was heavily forested with oaks, along with some maples, buckeyes, and redwoods. As Palo Alto was developed, citizens began to plan for street trees to create an urban forest. In the early days after the City was incorporated, members of the Women's Club carried milk cans full of water in their horse-drawn buggies to trees they had planted alongside the dirt roads. In 1902, school children helped to save many native oaks from being removed as hazards to motor cars.
Today, Palo Alto is easily spotted from airplanes and satellites because of the thick canopy of trees. The value of this urban forest is estimated at over $81 million.
Much of Palo Alto's forest was deliberately planted, and today it is aging, even declining. To perpetuate this forest for future generations, Palo Alto must undertake an on-going investment in tree planting, maintenance, and education.
What is the Urban Forest?
There are several different definitions, but what they generally agree on is that the urban forest is made up of the trees and vegetation in and around a town or city environment.Why does Palo Alto Need an Urban Forest?
There are lots of reasons!1. Beauty
- Trees create a tapestry of color and interesting form that changes throughout the year
- The color green is calming and helps your eyes recover quickly from strain
- Studies show that urban vegetation slows heartbeats, lowers blood pressure, and relaxes brain wave patterns
- Trees screen unattracive views and soften the harsh outline of masonry, metal, asphalt, steel and glass
2. Shade and Coolness
- Shade slows heat build-up from hard surfaces like driveways, patios, and sidewalks and can reduce the temperature in urban areas by as much as nine degrees
- A tree is a natural air conditioner; the evaporation from a single tree can produce the cooling effect of ten room-size air conditioners operating 20 hours a day
-People walk and jog more on shady streets, improving the sense of community as they stop and greet their neighbors
3. Economic Benefits
- Homes landscaped with trees sell more quickly and are worth 5 to 15% more
- Where the entire street is tree-lined, homes may be worth 25% more
- Trees enhance economic stability by attracting businesses; people linger and shop longer when trees are present
- Where a canopy of trees exists, apartments and offices rent more quickly and have a higher occupancy rate; workers report more productivity and less absenteeism
- Well-landscaped areas experience less crime against people or property
4. Save Energy
- Trees properly placed around buildings can reduce air-conditioning needs by 30% and energy used for heating by 20 to 50%
- By slowing wind speed, evergreen trees reduce winter heat loss from your home by 10 to 50%
5. Reduce Pollution and Noise
- One large tree can produce a day's supply of oxygen for four people
- An acre of trees absorbs as much carbon dioxide as a car produces in 26,000 miles
- Trees remove sulfur dioxide and nitrogen oxide, two major components of acid rain and ozone pollution, from the air
- Tree settle out dust, pollen, and smoke from the air. Dust levels can be 75% lower on the sheltered side of a tree than on the windward side
- Trees absorb and block sound, reducing noise pollution by as much as 40% (prolonged exposure to noise can cause hypertension, higher cholesterol levels, irritability, and aggressive behavior)
- Trees reduce surface water runoff from storms by 10 to 20%, decreasing the accumulation of sediments and chemicals in streams and reducing the severity of floods
Why does the Urban Forest Need Us?
1. Landscaping - Native oaks need us to landscape around them with minimal watering, using drought-tolerant plants, river rock or tan bark, to avoid root rot.2. Smart Placement - Trees need us to choose them wisely so that their branches don't interfere with power lines (eventually, the necessary pruning disrupts their natural growth patterns) or that their roots don't interfere with sidewalks.
3. A Good Start - For the first five years, newly planted trees need deep watering during hot summers. Weeds that compete for water must be kept out of the planting basin.
4. Long-Range Planning - The urban forest needs us to monitor its health. We must remove trees that are dying from old age, disease, or drought, and we must plant new trees to maintain the forest canopy.