Tree-Selection
Tree Selection in the Urban Forest
Trees that live a long time in the city is a massive accomplishment.
Selecting the planted tree
- To supply planting programs
- New construction or re-designs, improvements, enhancements
- Street tree replacement
- Afforestation or reforestation
Three elements that come into play
- The existing environment
- The landscape elements
- Design Intent
Sustainable Site Plan
- Assess Site Conditions
- Modify & Improve Site Conditions
- Plan Site to make best use of site characteristics
- Plan site to meet landscape objectives (Design intent)
The Site Assessment
- Soil Condition
- Site Contamination
- Underground Utilities
- Water Sources
- Transportation
- Current Use
- Stakeholder Preferences
- Maintenance Staff & Resources
- Existing Vegetation
- Sun/Shade Patterns
- Stormwater Flows
- Legal Restrictions
- Land Rights
- Wildlife Use
- Special Habitats or Plants
- Heritage Plants or Artifacts
- Vistas
Factors in Tree Selection
- Immediate Location
- Interactions within the site over time
- Interactions Beyond the site
- Urban Forest objectives
- Logistics
Immediate Location
We can take a linear approach;
- What are the site conditions?
- pH
- soil compaction
- drainage
- etc.
- Will our trees thrive in the exact location?
- Traditional "right plant, right place"
Interactions within the site over time
- Is there / will there be conflict / competition between species?
- Do understory vegetation (i.e., shrubs) have enough sun if the canopy matures?
Interactions Beyond The Site
- Supporting the larger ecosystem
- Become aware of what in the local area are some ecosystem needs
- Food and shelter for wildlife, pollinators, etc.
- Special environments
- Migratory stop-over for birds, butterflies
- Become aware of what in the local area are some ecosystem needs
- Not harming the larger ecosystem
- Do not plant invasive species
- Research exotic species thoroughly before using
- Behavior of species in their native environment, in other environments
- Invasive species screening protocols
- What is your biome?
- Will plantings naturalize? Will they cause harm?
Plant lists and "smart" systems
- Are useful tools to help you make sense of a complex situation
- Are useful for generating candidate lists of species
- Are not a substitute for knowing your species
- Are not a substitute for a robust design process
- Are not a substitute for a thorough site assessment
Summary
- There are a myriad issues to consider, consider them!
- You must know your species characteristics and ecological history -- dig deep before using a species
- Some sites/locations/climates are extremely limiting
- You are responsible for not causing ecological harm and need to research invasive potential
- A truly successful species selection decision is a major accomplishment and will benefit generations to come