What Urban Trees Do

• Palm trees shade a busy street.Medioimages/Photodisc/Photodisc/Getty Images
  
  Trees in an urban area are not only of aesthetic value, a study done by Harvard University shows the presence of trees reduces mental fatigue and improves concentration. The symptoms of children with ADHD are less severe where trees are present. The research shows aggressive and and violent behavior is reduced and crime rates are lower in city areas where trees are plentiful. The recovery of hospital patients is hastened when they can see trees from their window. Trees improve the quality of life.
  
  

More Jobs for Trees in the City

• A small girl gives a large tree a hug.Jupiterimages/Polka Dot/Getty Images
  
  In a city when temperatures soar, trees moderate the climate. It is much cooler on a summer day in an area shaded by trees as opposed to an area that is not. Trees take in pollutants and give back fresh air for us to breathe. According to North Carolina State University, one large tree can provide a day's oxygen for up to four people. Trees save us money. Air conditioning costs are less in urban areas heavily planted with trees. They reduce glare and give us privacy.
  
  

Using Trees to Prevent Erosion and Improve Water Quality

• Evergreens thrive near a reservoir.Jupiterimages/Comstock/Getty Images
  
  A study done by Virginia Tech in conjunction with Cornell and the University of California at Davis shows that tree roots have the potential to penetrate compacted sub soils and increase filtration rates in reservoirs. Researchers for all three universities say the study shows green ash trees increased the average infiltration by 27-fold, thereby improving water quality. According to the U.S. Forest Service, trees also prevent soil erosion. The tree serves as a retention basin drawing in the water through its roots and stabilizing the soil. The trees with the most leaf surface can hold more water. Evergreen trees serve best to combat runoff from rain at all times of the year.
  
  

Reading History by Tree Rings

• Tree rings in an ancient timber.Photos.com/Photos.com/Getty Images
  
  One man's understanding of the language of trees helped solidify the claims of the Navajo people in a dispute with the U.S. Government. The Navajo Nation was seeking reparation for the loss of land where they had made their homes at a specific time. Marvin A. Stokes, then a professor at the University of Arizona, was instrumental in proving the Navajo claims. Stokes confirmed the dates claimed by the tribe to be true by studying the tree rings in the timbers of the Navajo structures.