In this FACTivity, you will examine the rings on a cross-section of a tree trunk. Can you determine how old the tree is and what growing conditions it experienced? Then draw your own tree cross-section to illustrate your life experiences so far. Materials: Thin cross-sections of tree trunks or branches (also known as “tree cookies”); these can also be purchased or you can view pictures online. Paper and a writing utensil to draw This is the Spanish-language version of the FACTivity. Topics: Active Forest Management, Fire, Pollution, Water, Climate, Dendrochronology, Growing Conditions, History.