Urban Canopy Casualty

Urban Canopy Casualty

Louisville, KY recently conducted a study of its urban canopy and the results, which were just made public, are distressing to say the least. The city has been losing approximately 54,000 trees per year for the past several years, that amounts to the mortality of about 150 trees per day! Katy Schneider, co-chair of the Louisville Metro Tree Advisory Commission was involved in the research and states; “We have not managed this resource, up until now. As a result, we are losing canopy at … an alarming rate.”

The study was initially commissioned to study the economic and environmental benefits of trees, including improved air quality, heat island mitigation, decreasing storm water runoff, which in turn should help control and reduce erosion and sewage overflows. Over the nine years that were studied, 2004-2012, the rate of loss was approximately 7%. Although some neighborhoods felt the loss more deeply than others.

While (somewhat) natural causes are responsible. including intense storms, pests and disease, the city is also losing trees to construction and development. Additionally, the full effect of the Emerald Ash Borer has not been fully realized within the city limits, those losses are only beginning to become apparent and so have not been accounted for in this study.

In summary, Louisville’s urban canopy study revealed:

  • A loss of 54,000 trees per year, which would cost $25 million to replace,
  • An estimated $330 million in economic losses due to tree mortality, including $63 million from stormwater mitigation alone
  • And currently the urban canopy covers 37% of the city with optimal coverage coming in around 45%.