SUCCESS CASES
Study of the state and risk of León’s tree population
Agustín Jiménez | June 28, 2025
- Arboriculture
7 min.
The León City Council entrusted Tecnigral with the rigorous evaluation of the condition and risk of the municipal trees and, on that basis, to provide the city with a stable method of monitoring and continuous improvement. The objective was clear: to inspect with technical criteria, prioritize with proportionality and propose actions that make safety and conservation of the green heritage compatible.
Our approach
We design a work plan aligned with the specifications: methodology applicable to ordinary maintenance, first systematic evaluation and use of the most advanced instrumentation, culminating in management and maintenance guidelines to reduce and minimize risks as much as possible.
Quevedo Park. Anolisu. Own work, CC BY-SA 4.0
How we did it
We apply a three-phase strategy, designed to provide traceability and technical evidence for each decision:
- Phase I: Structured visual inspection (F1). We planned walking tours through roads and parks, with VTA/EVA visual inspection and preliminary risk categorization in a standardized card. Data collection was performed with Arbomap Inspections (mobile/Tablet), which ensured quality control, georeferencing and systematic photographs.
- Phase II: Detailed evaluation (F2 / ISA Report). For selected specimens, we prepare complete reports according to ISA Best Management Practices, incorporating more than 90 items per tree (targets, zone factors, health, loads, crown/trunk/root defects) and probability-consequence matrices for the overall assessment.
- Phase III: Instrumental witnessing. When necessary, we verified hypotheses with Sonic Tomograph (Picus) and Resistograph for wood, and Geo-radar (Tree Radar) for the root system, integrating graphs and interpretation in the reports. This objective layer allows refining diagnoses without overacting on the tree.
The entire field team consisted of arborists with experience in tree risk assessment who worked with homogeneous protocols, ensuring consistency in data collection and in the classification of proposals.
What we deliver
In addition to the individual reports and the photographic repository, we deliver a Risk Management Plan and pruning and maintenance guidelines, with proportionality criteria (reducing risk “to reasonable levels” without unnecessarily reducing the benefits of the trees), action priorities and review frequencies for monitoring.
MUSAC, León. Author: Zarateman. Creative Commons license
In addition to the reports and the photographic repository, we delivered a Risk Management Plan and pruning and maintenance guidelines.
Value for the city
The key to a sensitive issue is not to “do more”, but to do what is necessary, well and on time: comprehensive inspections, proven diagnostics and proportional actions that preserve valuable trees and protect people. With a scalable methodology, witnessing technology and traceable data in Arbomap, León now has a solid technical basis for deciding, prioritizing and communicating tree management with transparency and evidence.
Director of Arboriculture & Biodiversity North Central
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