The Nairobi City County has completed a groundbreaking digital inventory of every street and public park tree within its jurisdiction, creating a powerful tool to guide the capital’s future urban forest management. The massive undertaking, conducted in partnership with environmental organizations and community volunteers, involved mapping over 250,000 trees, recording their species, diameter, health condition, and GPS location. This living database, accessible to planners and the public, moves the management of the city’s green canopy from guesswork to data-driven strategy, allowing for targeted planting, proactive maintenance, and a clear assessment of the ecosystem services provided by this vital natural infrastructure.
The data from the inventory has revealed critical insights and vulnerabilities in Nairobi’s urban forest. It shows a concerning lack of species diversity, with a heavy reliance on a few non-native species like the grevillea, making the canopy highly susceptible to being wiped out by a single pest or disease. The inventory also identifies heat islands and neighborhoods with low tree cover, often correlating with low-income areas, highlighting issues of environmental injustice. With this information, the county can now strategically plant climate-resilient, drought-tolerant native species in these priority areas to provide shade, improve air quality, and reduce urban temperatures. The database also serves as a vital tool for protecting mature trees from unnecessary removal during development projects, as their documented value can now be quantitatively assessed.
The long-term vision is to integrate this tree inventory into the very fabric of Nairobi’s urban planning. The data will be used to set ambitious, measurable canopy cover goals, track carbon sequestration, and quantify the economic value of stormwater management and energy savings provided by the trees. The success of Nairobi’s project is already inspiring other major Kenyan towns like Mombasa and Kisumu to initiate their own inventories. By knowing what trees it has and where they are needed most, Nairobi is not just planting trees—it is engineering a smarter, healthier, and more resilient urban ecosystem for the challenges of the 21st century, ensuring its green legacy thrives for generations to come.