a thin layer of living, dividing cells just under the bark of trees. This layer gives rise to the tree’s secondary growth.
pltintern
Christine Song supports both Project Learning Tree (PLT) US and Canada's program delivery and reporting, program research, and communications. Christine holds a Master of Environmental Science from the University of Toronto and and a combined degree with a Bachelor of Science in ecology and zoology and a Bachelor of Science in anthropology from the University of Calgary.
