During the hottest hours of summer, ground temperature under the canopy of a mature tree is several degrees lower than in an exposed area. This is not a perceived effect: it is a measurable physical fact, driven by shading and canopy evapotranspiration. For anyone designing or supplying plants for urban green projects — public, corporate or commercial — this has a direct implication: species choice is not an aesthetic detail, it is a performance variable.
Three Concrete Ecosystem Services
A mature tree in an urban setting delivers three verifiable functions, increasingly required in specifications with sustainability requirements:
1. Cooling
Canopy shading and leaf evapotranspiration lower air and surface temperature in the surrounding area, with a measurable impact on so-called urban heat islands — the areas where asphalt and concrete accumulate heat during summer months.
2. Stormwater management
Root systems, particularly in mature specimens, aid water infiltration into the soil and slow surface runoff during heavy rainfall events, reducing the load on drainage networks.
3. Habitat and biodiversity
The canopy, bark and any trunk cavities host insects, birds and other wildlife, contributing to urban biodiversity — an indicator increasingly present in ESG reporting for public bodies and companies.
What This Means in Practice for Species Selection
Translating these ecosystem services into a purchasing decision requires precise technical criteria, not simply “a large tree”:
- Canopy width and density: a broad, spreading canopy produces more ground-level shading than a fastigiate or columnar crown — the form should be chosen based on available space and the required cooling effect
- Root system: needs to be assessed in relation to underground services and surrounding pavements, balancing water infiltration capacity with compatibility with existing infrastructure
- Growth rate to maturity: slower-growing species take longer to reach the canopy size that generates these benefits — a factor to consider in a project’s long-term planning
- Drought and urban stress tolerance: poor soils, water stress and pollution require species with documented tolerance, to ensure the tree actually reaches the maturity that delivers these benefits
The Supplier’s Role in Species Selection
For a buyer — a landscaping firm, public body, or retail chain delivering turnkey projects — choosing the right species for the specific context (exposure, available space, soil type, project objective) requires technical discussion with the grower, not just a catalogue lookup.
Vivai Reali grows 90-95% of its catalogue in-house on 30 hectares in Pistoia, with a Stock List updated in real time on infoplant. For identifying the tree species best suited to an urban green project with specific cooling, water management or biodiversity objectives, the sales team is available for a direct assessment.
