They were never really there

Urban tree mortality varies by species, age, growing conditions, and care. A tree beside a polluted, compacted roadside is more vulnerable than one in the middle of a park. Yet a plane tree may flourish despite these stresses if it is well cared for in the years immediately after planting.

Trees planted in cities are often chosen for their tolerance of a changing climate, but they still require support to withstand drought, pests, and flooding. As a rule, urban trees grow faster and die younger than they would in their natural environments.

In my local park, two established trees — a stone pine and a ginkgo — fell during winter storms. Although otherwise healthy, their shallow roots could not withstand high winds.