Urban wood is a resource we can’t allow to treat as waste. US Forestry provides some insight about the reasons behind the availability of urban wood.

The staggering number of tree removals in cities and towns across the
country becomes necessary for a host of reasons. Storm blowdowns,
natural mortality, severe insect and disease damage, construction activities,
and many other circumstances can change an urban tree from an asset
into a liability. Municipalities are faced not only with the volume of tree
removals but with the associated financial costs as well.

STEPHEN M. BRATKOVICH (United States Department of Agriculture
Forest Service
Northeastern Area
State and Private Forestry)