Jack Phillips, executive director of the Portland Parks Conservancy at Deering Oaks Park in July 2026. “We’re facing pretty strong headwinds,” said Jack Phillips, executive director of Portland Parks Conservancy, who estimates that the city is planting only two trees for every three it loses. To fight back against these challenges, the conservancy has partnered with the city and a consulting firm to develop an urban forest master plan. City arborist Mark Reiland inspects an ash tree near the intersection of Spring and High streets in Portland in 2024. Ash trees there have been treated against an infestation by emerald ash borers, insects that are responsible for the deaths of many ash trees throughout the city.