Celine Colbert is Pennsylvania’s Tree Canopy Coordinator, dedicated to enhancing urban forestry and promoting sustainable tree management across the state. As a Board Certified Master Arborist with a background in forestry, Celine collaborates with local governments, organizations, and communities to implement effective tree planting and maintenance programs offering technical assistance, grant matchmaking, and tools such as the DCNR (Department of Conservation and Natural Resources) TreeKeeper.

Dave Muffly has been planting trees (especially oaks) in the Bay Area and other California locations for more than 30 years. Dave began his tree career when he received his undergraduate degree in mechanical engineering, at Stanford University. Moving from engineering to ecology, Dave managed native oak plantings at Stanford with the non-profit Magic, in a project that has yielded more than 4,000 established oaks in 40 years. Dave then branched into fruit trees, and urban tree plantings, with a special focus on street trees.

Dave subsequently became a Board Certified Master Arborist and designed/oversaw the 101 Freeway Soundwall planting as part of the East Palo Alto Tree Initiative led by the non-profit Canopy. This radical and experimental 1000-tree drought adaptation planting succeeded far beyond expectations and laid the foundation for the changes reverberating through the California tree nursery industry today. The East Palo Alto Tree Initiative became the proof of concept for the even more radically diverse plantings at Apple Park in Cupertino, where Dave spent seven years as Apple's Senior Arborist. Today Dave works as a senior arborist and horticultural futurist.