Facts About Atlantic White Cedar, Chamaecyparis thyoides (L.) B S.P

Related Species: Atlantic white cedar is a member of the cypress family to which the junipers, including red cedar, and Northern white cedar or arborvitae belong. This group is distinguished from other cone-bearing evergreens by overlapping scale-like or awl-shaped foliage and small unusual cones.

Abundance and Distribution: Mid Coast Maine is the northern limit of Atlantic white cedar’s range. There are two large stands located in that region. The remaining large stands are located in York County. Most all of the cedar in Maine is found along the coastal plain, no more than 15 miles inland and between 200 and 250 feet of elevation above sea level. Five large populations of this species (100 acres or more) are found in Alfred, Berwick, Saco and Sanford. Smaller isolated stands are found in Elliot, Sanford and York. Sanford is home to two large and at least four small stands.

Ecology: Atlantic white cedar is intolerant of dense shade and is a long enduring, replaceable species restricted to wetland hummocks because of seedling requirements. These hummocks most likely originate from wind fallen trees that decay and leave behind a mound. Seedlings do not survive in water. Thus, they grow on these mounds that are above water most of the time. Cedar will replace itself or invade a new site only if the existing canopy is removed by fire, wind throw or logging. Fire probably has been the natural factor in the establishment and regeneration of cedar swamps because it eliminates competing woody vegetation and releases nutrients which stimulate rapid cedar growth. The control of forest fires has eliminated the role of fire. Without catastrophic events, red maple, along with other hardwoods, slowly fill in the gaps created by the blow down or death of cedars. This replacement may be favored by the lowering of the water table through the evaporation of huge quantities of water from the dense canopy of cedar trees. Thus, in time the swamp may become dominated by red maple trees, one of the most common wetland forest communities. In our area, road construction, storm water runoff, swamp drainage and beavers threaten the quantity and quality of water in cedar swamps. Of these, beavers are most often the greatest threat.

Uses: Most of the members of the cypress family are used as landscape specimens. This is certainly true of Atlantic white cedar which has 42 varieties that differ in color, growth habit and height. This species further south is a commercially important timber species. Although here in Maine it is not abundant enough to be that important, Indians used the straight grained, easily worked wood for canoes, tinder for starting fires and possibly to construct their homes. Settlers found cedar useful for posts, fencing, log cabins, siding, flooring, barrels, tubs, boats and water and organ pipes.

Cedar charcoal was used during the Revolution to make gunpowder. Many communities held cedar swamps ” in Common” for public use because of the value of the wood. This practice contributed to modern day rarity. Since this species was never as abundant as other trees prior to the arrival of the settlers, harvesting and development have reduced the number and size of cedar swamps over the last four hundred years.

The largest Atlantic white cedar tree discovered in Maine thus far is located within the Massabesic Experimental Forest. In 1999, it had a diameter at breast height of 21.6 inches, a crown diameter of 19 feet and a height of 63 feet. A tree of this size is probably well over 200 years old.