A tree inventory is a inventory and health assessment of all the mature trees present on a property.  Typically, only trees that are 5 cm or larger at breast height are assessed.  The inventory is undertaken by a certified Arborist and is a more detailed method of assessing the tree community on a property as the specific location of each individual tree is recorded through land survey, digitized and included within the drawing set of a site plan application.  The information obtained during a tree inventory is utilized to direct the preservation of tree resources during site plan design.  This is an important consideration given the ecological value of mature trees, and the amount of time and resources required to replicate the same ecological value if a mature specimen is removed and a replacement planted from seed or sapling.