Trees

Objectives:
  • Create a basic understanding of tree taxonomy, biology, and function within an environment.
  • Build an awareness of the benefits of trees within the urban landscape
  • Conduct field tree identification

Essential Questions:
  • What do trees give us?
  • What functions/systems are apart of a healthy tree?
  • How do trees fit into the urban environment?
  • How can we care for trees?
  • What do trees do for our ecology?

Materials:

Anticipatory Set:
Show the following clip about the importance of a tree:  http://woodycreekpictures.com/films/tree-story/


Benefits of Trees Brainstorm: 
Using students contributions create a brainstorm or map of the “Benefits of Trees”. Have students copy the brainstorm into their notes. (The following list is taken from TreePeople’s Citizen Arborist course materials, and is offered here simply as a starting point to spur on the dialogue between instructor and student.)

  • Benefits of Trees:
    • Clean the air:
      • reducing the risk of asthma and increasing the desire to play outside.
      • Frequent exercise helps maintain a healthy weight and prevent diabetes. Trees and shrubs
      • help to mitigate this harm by removing particulate matter, ozone, nitrogen dioxide, carbon monoxide, carbon dioxide, and sulfur dioxide. In fact, urban trees and shrubs in Los Angeles alone are estimated to remove 4,500 tons of air pollution per year.
    • Capture and clean water:
      • Trees reduce runoff by breaking rainfall, allowing the water to flow down the trunk and into the earth below the tree. This prevents stormwater from carrying pollutants to the ocean.
      • When mulched, trees act like a sponge that filters this water naturally and uses it to recharge groundwater supplies.
    • Save energy:
      • Three trees placed strategically around a single-family home can cut summer air conditioning needs by up to 50 percent. By reducing the energy demand for cooling our houses, we reduce carbon dioxide and other pollution emissions from power plants.
    • Combat the greenhouse effect:
      • Trees absorb CO2, removing and storing the carbon while releasing the oxygen back into the air. In one year, an acre of mature trees absorbs the amount of CO2 produced when you drive your car 26,000 miles.
    • Create safe and healthy living:
      • A healthy environment is created through healthy mature trees. In a survey of inner-city neighborhoods, researchers observed an inverse correlation between the amount of vegetation and the number of violent and property crimes—the more trees, the lower the crime rate. Further, respondents reported lower levels of fear and aggressive behavior.
Vocabulary:
  • mulch: A material (such as decaying leaves, bark, or compost) spread around or over a plant to enrich the soil, keep weeds down, and retain water.
  • Greenhouse Effect: Man made gases in our atmosphere trap heat and increase temperatures here on earth.
  • deciduous: A tree or shrub which loses its leaves each year.
  • evergreen: A tree or shrub which keep its leaves all year long.
  • canopy: The cover formed by the leafy upper branches of the trees in a forest

Tree Anatomy:
  • Reviewing the attached handout, briefly discuss all the parts of the tree and their various functions.
  • Have students tape this handout into their journal.

LeafSnap Field Research:
  • Hopefully a handful of students in the classroom have cellular devices. If not, a classroom ipad or teacher mobile device may be used.
  • Download the application “Leafsnap” (http://leafsnap.com/)
    • Leafsnap is an application developed in colaboration by Columbia University, the University of Maryland, and the Smithsonian Institution. Using computer programing originally designed for facial recognition, Leafsnap allows for automatic species identification. By taking a photo of a leaf, leafsnap cross references it with its database of high resolution leaf, flower, bark, and fruit photos, to assist the user in identifying the given tree or plant.
    • Take a trip out to the school yard, and have students in groups select three to four leaves. Have students look for leaves that have distinct shapes and characteristics.
    • Bring the leaves back to class, and using the app have students attempt to identify which plant or tree the leaves belong to. Looking careful at the leaves edge (are they smooth or serrated), the veins of the tree, is it broad leafed or narrow, and so on.
    • If it is difficult to determine a definite answer, have students write down their top three guesses.
    • Students should write down:
      • Common Name
      • Latin Name
      • Brief description of the tree
      • Habitat
      • Growth Habit
      • Bloom Time