Louisville Urban Tree Canopy Assessment

At the recommendation of the Louisville Metro Tree Advisory Commission, a countywide urban tree canopy (UTC) study was conducted in Louisville, Kentucky. The study was designed to determine the historic and current amount and location of tree cover, quantify the benefits, set realistic goals to expand the tree canopy, and make recommendations for achieving these goals.

Louisville’s tree canopy was accurately mapped and then analyzed by a multitude of factors including land use, surface temperature, and demographics. Additionally, canopy was segmented by council districts, neighborhoods, suburban cities and sewersheds.

This report provides an overview of the UTC process, assessment results, and recommendations for tree planting and management strategies.

In the Canopy & Socioeconomics section of the assessment, this assessment describes canopy coverage at the census tract and council district levels considering socioeconomic and demographic data. This analysis helps identify trends and priority areas, providing direction for establishing planting goals. Findings include:

  • Canopy is higher (up to twice as high) in wealthier areas than in lower-income tracts.
  • Canopy decreases as population density increases.
  • Canopy is higher in areas dominated by high-value homes.

 

  • Canopy is higher in areas with higher percentages of older residents (ages 45 and older). These groups tended to live in the outer areas of Louisville, along with a smaller concentration along the inner loop closer to the downtown area.
  • Higher tree canopy is strongly correlated with home ownership. Canopy tends to be lower in areas dominated by rental properties, and higher in areas with majority owner-occupied houses.
  • Canopy is higher in areas with higher educated residents.
  • Canopy potential increases as the concentration of newer homes increase.  Canopy was found to decrease in only those structures built before 1950.  Older structures concentrated around the older city center of Louisville are, in general, more urban with less space for tree canopy.

The assessment notes that further analysis is required to assess actual population vulnerability to heat, especially at the neighborhood level. Nonetheless, reducing temperature differentials countywide may be achieved in a shorter time by accelerating tree planting in multi-family, commercial, and industrial areas, which make up 63% of all hot spots.


Based on the findings of the UTC study, the report offers recommendations for growing and protecting the tree canopy in Louisville. Thousands of young trees will need to be planted and thousands of mature trees will need to be cared for if trees are to be utilized as a way to reduce stormwater issues, improve air and water quality, and reduce the urban heat island effects in Louisville.

A prioritized planting plan was also created to maximize tree benefits in areas of greatest need. Plantable areas were evaluated based on environmental features (proximity to local waterways, soil type, floodplains, slope, and forest fragmentation), stormwater issues, and urban heat island concerns.

If current trends hold, Louisville canopy is projected to decrease to 31-35% in the next ten years, dropping to as low as 21% over the next forty years.

Louisville’s current canopy provides $330 million in benefits each year. This includes annually intercepting over 18 billion gallons of stormwater, removing 150,000 lbs. of carbon monoxide, 4.3 million lbs. of ozone, 500,000 lbs. of nitrogen dioxide, 600,000 lbs. of sulfur dioxide, and 1.2 million lbs. of soot, dust and other particulates.

 

 

Publication Date: March 1, 2015

Related Organizations:

  • Louisville Metro Tree Advisory Commission

Sectors:

Resource Category:

Resource Types:

  • Assessment

States Affected:

Impacts:

  • Air temperature

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