Fort Collins’ urban forest includes trees growing along streets, in public parks and natural areas, and in the yards of homes, schools, and businesses. Together, these trees are a dynamic, living system that provides invaluable environmental, economic, and societal benefits to enhance the quality of life in Fort Collins.

Summary of Findings

This image demonstrates the Strategic Planning Approach. First asking, "What do we have?", next asking "What do we want?", then "How do we get there?", and finally "How are we doing?"

• Tree canopy cover in Fort Collins is 12.6% and has grown steadily over the past decade. The extent of tree cover varies widely across the city and the growth management area, ranging from almost no trees to over 40% tree cover.
• The largest gains in tree cover took place within low-canopy areas near the borders of the city, while canopy losses tended to take place within the more densely developed and treed urban core.
• The inventory of 61,388 public trees and planting sites in Fort Collins revealed that the biodiversity of public trees is approaching a level that will help the urban forest remain resilient to pests and diseases. Future management considerations should include planting species that are resilient to emerging pests, diseases, and drought.
• The condition of public trees reflects significant investments in routine maintenance as the Forestry Division moves toward its goal of a five-year pruning cycle and away from reactive maintenance, which is comparably more costly.
• Fort Collins’ public trees skew young, reflecting an uptick in more recent tree plantings that are associated with city activities and increased development. Future maintenance needs are expected to increase over time as new trees are planted and existing trees grow into larger size classes, which will require additional resources for the Forestry Division to keep pace.

Additional Details

TREES SUPPORT FORT COLLINS’ STRATEGIC OBJECTIVES

The City of Fort Collins 2024 Strategic Plan outlines seven Key Outcome Areas by which the City measures progress toward its vision and goals. Trees relate to each of these seven Outcome Areas through the many benefits that they provide.

1. Neighborhood & Community Vitality. Trees improve wellbeing and health outcomes in people by cleaning and cooling the air and reducing stress.
2. Culture & Recreation. Trees add to the beauty and character of Fort Collins and encourage people to spend more time outdoors.
3. Economic Health. Trees in business districts encourage people to stay longer and participate in the local economy. Trees add value to properties and help residents save money on energy costs.
4. Environmental Health. Trees provide habitat for wildlife and absorb carbon and other greenhouse gasses that contribute to climate change.
5. Safe Community. Well-maintained trees build a sense of community and are associated with reductions in crime.
6. Transportation & Mobility. Trees slow traffic and make streets and sidewalks safer and more comfortable for active modes of transportation.
7. High Performing Government. The Forestry Division proactively maintains public trees and responds to hundreds of resident requests each year. It also influences private tree stewardship through arborist licensing, City code implementation, and tree protection and protection requirements for development.

FORT COLLINS’ TREE CANOPY COVER HAS GROWN TO 13.7%

Urban tree canopy was measured across Fort Collins—where it is, how it is changing, the benefits it provides to residents, and where potential tree planting opportunities exist. The analysis used high-resolution aerial imagery from 2011 and 2021 to measure tree canopy cover across the city as viewed from above. It looked at land within the current city limits as well as the growth management area, which delineates the possible future extent of city boundaries.

Average tree canopy cover in Fort Collins and the growth management area is 13.7%. Tree cover varies widely, ranging from almost no trees in some parts of the city to over 40% tree cover. In general, tree cover tends to be highest within the oldest parts of the city, where residents have been planting trees since the nineteenth century.

From 2011–2021, the city and the growth management area experienced an overall increase in tree canopy cover of 17.2%. The largest gains in tree cover took place within low-canopy areas near the borders of the city, while canopy losses tended to take place within the more densely developed urban core. While the tree canopy study can tell us where canopy gains and losses have occurred over time, it cannot answer specific questions about the causes of tree canopy change. However, it is known that the older age of trees within the urban core, urban environmental stressors, and development (both new and infill) are all possible drivers of canopy change over the study period.

RESIDENTIAL LAND CONTAINS THE MOST EXISTING TREE CANOPY—AND THE GREATEST POTENTIAL FOR MORE This bar graph shows tree canopy cover by land use type in Fort Collins from 2011 to 2021. Residential areas have the most tree cover and potential for future growth. Most land types, except for commercial and industrial areas, saw an increase in tree cover during this period.

In Fort Collins, residential land contains over half of the city’s tree canopy (Figure 3). Tree canopy has grown 15% on residential land since 2011. The largest tree canopy losses by total acreage have taken place on commercial land, which lost 30 acres (-10%) of tree cover since 2011.

The largest potential for additional tree canopy occurs within residential and mixed-use zoning types, which together contain 8,083 acres of possible additional tree canopy.

THE SPECIES COMPOSITION, SIZE, AND CONDITION OF CITY-MANAGED (PUBLIC) TREES

This images demonstrates the public trees and planting sites that are documented in a tree management software, TreeKeeper. 38,660 (two thirds) of Fort Collins' 57,991 public trees are street trees.

From 2018–2023, the Forestry Division and trained volunteers from the City’s Urban Forest Ambassador program updated the public tree inventory, documenting 57,991 trees, 2,668 vacant planting sites, and 729 stumps within street rights-of-way, parks, and City-owned property. Detailed information about public trees is used by the Forestry Division to guide management decisions.

PUBLIC TREES TREND CLOSE TO RECOMMENDED BIODIVERSITY GUIDELINES

Biodiversity helps to make the tree population resilient to pests and diseases. The importance of biodiversity can be seen in the effects of emerald ash borer, which threatens 13% of existing public trees that are in the genus Fraxinus.

There are at least 214 unique species of trees within the public tree inventory that represent 56 genera and 26 families. At a species level, the biodiversity of public trees is approaching the urban forestry industry guideline of no more than 10% of a single species present in the inventory.

Today, both green ash and honeylocust exceed recommended limits for species abundance. The abundance of all ash species is expected to decline over time due to emerald ash borer. The Forestry Division is reducing the planting of honeylocust on public property and is encouraging developers to shift away from planting honeylocust as part of required street tree plantings that are associated with development.

Genus- and family-level biodiversity is also important, as many tree pests and diseases have the ability to attack multiple related species. It is recommended that no one genus should comprise more than 20% of the tree inventory, and no one family should comprise more than 30%. The tree genera and families in the public inventory remain below these thresholds; however, the pest and disease susceptibility of the larger tree population remains unknown.

PUBLIC TREES ARE IN GOOD CONDITION

The condition of public trees reflects significant investments in routine maintenance as the Forestry Division moves toward its goal of a five-year pruning cycle and away from reactive maintenance, which is comparably more costly.

More than half of public trees (55%) are rated to be in Good or Fair-Plus condition, meaning that their trunks and crowns are generally healthy and strong (Figure 5). An additional one-third (34%) are rated to be in Fair condition, indicating that they are healthy and show no major defects.

PUBLIC TREES SKEW YOUNG

A mixed-age tree population balances the maintenance needs of public trees over time and protects against significant canopy loss. Sixty percent of public trees in Fort Collins are young, reflecting sustained tree planting efforts within the city, including tree planting that occurs through new development as the city has grown.

Care of young trees during establishment, as well as proactive maintenance of older age classes, will help increase the proportion of older trees to balance age classes over time. As the urban forest grows, the benefits that it provides will increase. In the next 20 years, at the present rate of planting, the population of public trees is projected to shift toward more medium sized trees.