Annikki Mäkelä earned her MSc in Engineering (1980) and Licentiate Tech. (1982) in Systems Theory at the Helsinki University of Technology (HUT), and PhD in Forestry (1988) at the University of Helsinki (UH). After her graduation she held several research positions at HUT’s Systems Theory Lab and UH’s Department of Silviculture (later Forest Ecology, then Forest Sciences), many of them funded by the Academy of Finland. She was appointed Professor of Silviculture/Applied Forest Ecology at UH in 2005. Dr. Mäkelä has primary research interests in the area of growth, production, carbon balance and population dynamics of boreal forests and practical applications of quantitative models to forest management. She leads the Forest Modelling Group at the UH Department of Forest Sciences where she also teaches undergraduate and graduate courses on modelling tree and stand growth. She has been involved in several national, European and global research projects and networks developing and using forest models, with a strong focus on scaling issues and regional applications of process-based models to management questons under climate change. Harry T. Valentine earned a B.S. in forestry at Rutgers University in 1970, and then emerged from Yale University with an M.F., Ph.D., and budding interests in sampling, modelling, and forest ecology. He spent his entire professional career as a scientist with the Northern Research Station, USDA Forest Service, starting in 1974 and ending with his retirement in 2016. The first decade of Dr. Valentine's career was spent working on forest insect and disease problems. After 1984, most of his research was concerned with either: a) devising new methods for sampling attributes of trees or forests, or b) achieving a balance between process and applicability in process-based models of trees and stands. Dr. Valentine is co-author, with T.G. Gregoire, of a book entitled: Sampling Strategies for Natural Resources and the Environment.