Tree Facts

Carbon sequestration, air quality, and climate change

  • A tree can absorb as much as 48 pounds of carbon dioxide per year, and can sequester one ton of carbon dioxide by the time it reaches 40 years old. [1]
  • One large tree can provide a supply of oxygen for two people. [2]

Energy

  • According to the USDA Forest Service, “Trees properly placed around buildings can reduce air conditioning needs by 30 percent and save 20-50 percent in energy used for heating.” [3]
  • The net cooling effect of a young, healthy tree is equivalent to ten room-size air conditioners operating 20 hours a day. [4]

Water

  • In one day, one large tree can lift up to 100 gallons of water out of the ground and discharge it into the air. [5]
  • For every five percent of tree cover added to a community, stormwater runoff is reduced by approximately two percent. [6]

Recreation and Wildlife

  • Healthy trees provide wildlife habitat and contribute to the social and economic well-being of landowners and community residents. [7]

EPA Urban Heat Island Effects

  • Reduced energy use: Trees and vegetation that directly shade buildings decrease demand for air conditioning.
  • Improved air quality and lower greenhouse gas emissions: By reducing energy demand, trees and vegetation decrease the production of associated air pollution and greenhouse gas emissions. They also remove air pollutants and store and sequester carbon dioxide.
  • Enhanced storm water management and water quality: Vegetation reduces runoff and improves water quality by absorbing and filtering rainwater.
  • Reduced pavement maintenance: Tree shade can slow deterioration of street pavement, decreasing the amount of maintenance needed.
  • Improved quality of life: Trees and vegetation provide aesthetic value, habitat for many species, and can reduce noise

Life Span 

A reasonable estimate of the lifetime of trees is 100-150 years. Based on information from the USDA Forest Service [9], the lifetime of trees varies by region and species, but generally ranges from 50 years to 300 years of age. An average lifetime of trees planted in forests for long-term restoration purposes might be 100-150 years. Here are a few examples by region
  • In the Southeast, conifers may live 100-150 years, while hardwoods may live 150-200 years.
  • In the northeast and lake states, some conifers (e.g. white pine and red pine) may live 100-150 years, while Jack pine lives 80-100 years; mixed hardwoods (e.g. maples and oaks) might live beyond 150 years, while aspen and birch might only live 50-70 years.
  • In the Pacific Northwest, conifers may live 200-300 years and longer.

Facts and Figures on Forests

Forests cover land all over Earth in varying degrees. Some of the most forest-rich countries include Brazil, Canada, the United States, China, and Australia. It’s estimated that forests cover about 30 percent of Earth’s total land area, and of this acreage, more than one-third of the forests are considered primary forests. Primary forests have no clear evidence of human activity or significant disturbance. Scientists estimate that Earth’s forests store 283 gigatons of carbon, accounting for 50% more carbon than the amount found in our atmosphere.

  • U.S. Forests Facts and Historical Trends (PDF): The percentage of forest land in the United States has been mostly stable for more than 100 years.
  • Facts About Wood (PDF): About two-thirds of the forest area that covers the United States is sufficiently productive to grow trees used for commercial purposes.
  • Our World in Data: Forests: Human settlement has historically involved deforestation over time. However, some countries are successfully reversing this trend.
  • The State of the World’s Forests: As the population grows, the need for food will increase along with it. Although deforestation may seem necessary to convert land to agricultural use, this change can lead to other negative impacts on the environment.

How to Plant a Tree

The best time to plant a tree is during the dormant season in temperate zones and during the rainy season in tropical and subtropical regions. Preparing the planting site correctly, placing the tree into the ground carefully, and caring for the tree diligently after planting are all important factors that will help a newly planted tree grow and thrive. In the Pacific Northwest we have the best success planting in the Fall but as long as you can commit to watering the tree throughout the summer for at least two years you can successfully plant trees and plants anytime of the year. 

Step 1

The first step in planting a tree is to dig a hole that is at least two to three times wider than the root ball, which allows the roots to spread. Make the hole deep enough so that when you place the tree in the hole, the root collar sits just above or level with the top of the hole.

Step 2

Loosen the root ball gently before you place it into the prepared hole, and situate the tree in the hole so it’s straight. Consider using a pole to support it while it grows.

Step 3

Fill the hole with soil and pat it firmly to finish planting. Add arborist mulch or other types of bark chips around the tree to help keep water in the soil and provide nutrients. 

Step 4

Water the newly planted tree, but don’t fertilize it. Keep the tree adequately watered for the first few months, and remove any weeds that grow around the tree. During any dry seasons you will need to water it for at least two seasons to make sure the roots grow and have access to water on its own. Tree irrigation bags are great to use for this purpose and greatly lowers the amount of watering trips that need to be taken. 

 

 


[2] McAliney, Mike. Arguments for Land Conservation: Documentation and Information Sources for Land Resources Protection, Trust for Public Land, Sacramento, CA, December, 1993

[3] http://www.savatree.com/whytrees.html

[4] http://www.dnr.state.oh.us/Home/urban/features/trimming/tabid/5464/Default.aspx

[5] http://www.ncsu.edu/project/treesofstrength/treefact.htm

[6] Benefits of Urban Trees. Compiled by Keep Indianapolis Beautiful, Inc

[7] http://www.unl.edu/nac/workingtrees/wtw.pdf

[8] http://www.epa.gov/heatisland/mitigation/trees.htm

[9] Discussions with Monty Maldonado, U.S. Forest Service, Forests Management, tree planting program, October 5, 2011