Trees are a fundamental source of life, especially in cities where they provide many environmental benefits, like temperature regulation, CO2 capture, turbulent air reduction, as well as improvements in psychological wellbeing, housing prices, etc.
As such, their protection is essential. A mature tree takes between 15 and 20 years to develop and with a heavy snowfall, it takes only two days for many to collapse.
The work of our colleagues at Valoriza Medioambiente has intensified in the last month, though they have managed the green zones of public parks and roadside trees in Madrid for years. They work as part of a temporary consortium (UTE) with other entities in Madrid’s Green Zone Assessment and Review Service (Servcio de Evaluación y Revisión de Zonas verdes, “SERVER”), which has reviewed at-risk trees for the past two and a half years.
“With 1,700,000 trees, Madrid is one of the cities with the most trees in the world. There are 530,000 mature trees that fall under the scope of our management,” explains Diego Martínez, SERVER service technician.
Tree conservation and monitoring
“Our role is divided into two areas: tree conservation and monitoring at-risk trees. There are about 40 inspectors who respond to incident calls from firefighters, police, and citizens. We have inspection forms that we upload to an application with 90 fields; this is where we compile the tree’s various characteristics.
For those at medium/high risk, we take action to safeguard the tree and eliminate that risk,” says Gaspar Soria, geographic IS technician at SERVER. “We try to avoid removal to the extent possible; risk mitigation is always approached from a conservationist perspective, as a preventative service. [...] If we notice a tree in imminent danger (tilting, etc.), we file an incident report and dispatch teams immediately to eliminate the risk,” Gaspar adds.
Technology for trees
The inspectors pinpoint the defect(s) of trees in poor condition and determine their level of risk based on these assessments. They use resistographs to measure the wood’s resistance, tomographs to identify possible infections from fungi and other external elements, and tree-radar to assess the condition of the roots.
The most predominant tree species in Madrid are the London Plane and the Siberian elm, followed by the stone pine and the Japanese pagoda.
In addition to these services, they also preform research based on collecting data and tracking patterns in tree failures, etc. This in-depth pattern analysis is taken into account when examining the data of each tree.
Snowfall in Madrid
The recent snowfall in Madrid has posed a challenge for the team. According to Diego Martínez, major storm events cause an average of 500 to 600 incidents. “This storm caused more than 5,000 incidents, and there are still some areas yet to explore. The stone pine is a coastal tree, unaccustomed to developing structurally under these inclement weather conditions. Their 3- to 4-meter canopies have had to support as much as two tons of snow, causing countless broken branches.”
The team receives calls 24/7. “That Sunday, when the snow arrived, we started working. We prioritized fallen trees at hospitals, schools, or blocking roadways, etc. Now we are checking for split limbs, mainly in parks,” Diego Martínez affirms.
Treatment of fallen branches
A very important part of this process is the treatment of fallen branches. As Gaspar Soria explains, the limbs are taken to the Migas Calientes composting center near Casa de Campo. “All the branches are crushed for subsequent treatment in making compost. The remains are re-used as fertilizer for parks and gardens.”
