An Acacia tree that stood proudly for over a century at the Malacañang Palace grounds in Manila has witnessed the transition of more than 14 Philippine Presidents – from Manuel L. Quezon to Benigno S. Aquino III. Located at the country’s seat of power, the tree has been a strong fixture, able to withstand wars, coup d’etat attempts, and the passage of time. Today, that tree is no more.
Typhoon Glenda, internationally-known as Rammasun, pummeled Luzon and parts of the Visayas last 16 July 2014. The typhoon packed wind speeds of up to 150 kilometers per hour and gusts of up to 165 kph.
Similar scenes of felled trees were seen along its trail of destruction. Trees with massive trunks littered the streets of Makati City, the Philippines’ financial center. In the province of Albay, Governor Joey Salceda is considering what to do with the Bicol University’s 107-year-old tree that was uprooted at the height of the typhoon.
In some cases, trees added to the damage wrought by the typhoon. Trees flattened cars and electric power lines, causing widespread power outages.
Top environmental solutions-provider World Wide Fund for Nature (WWF-Philippines) outlines key ways to manage our trees and make them more storm-resistant:
1. Find out what makes trees vulnerable to storms.
Trees planted in loose, rocky soil stand a high chance of being uprooted. Disease, damaged roots or trunks, plus pest problems can also weaken trees. Says WWF-Philippines Vice-president for Project Development Luz Baskiñas: “Trees not strongly anchored to the soil are vulnerable to leaning, uprooting and trunk damage. Those with numerous lateral branches and leaves are vulnerable to defoliation, with branches easily snapped off.”
Baskiñas says a combination of factors affects the ability of trees to resist tropical cyclones. Environmental factors include the slope, elevation, exposure, soil type, plus depth. Inherent genetic and morphological characteristics of trees like height, diameter, foliage size, crown structure, root length, plus depth all shape a tree’s vulnerability. Baskiñas suggests that a typhoon risk assessment for urban trees, plus species suitability studies, be undertaken.
2. Prioritize planting trees native to the Philippines.
Anthony Arbias, President of the Philippine Native Plant Conservation Society, Inc. (PNPCSI), observed that most of the toppled trees were the ‘exotic’ ones, such as Mahogany, Gmelina, Acacia, Fire Tree, and Teak wood.
“Because most of these exotic trees are planted on ‘foreign’ soil like ours, there is naturally a major mismatch with Philippine weather patterns, soil, wind, water, and other elements that would challenge their existence with vulnerability or destruction,” Arbias notes.
Examples of native trees are Narra, Molave, Lagundi, Dita Batino, Pandakaki, Balete, and Kalios. “The typhoon was a wake-up call on the vulnerabilities of exotic trees against natural elements. We should set our attention to a more patriotic and ecologically-sound approach on restoring vegetation by using native trees. After all, we have more than 3500 species of native trees to choose from, and they are all part of our natural heritage,” he adds.
3. Re-plant trees that are able to withstand ferocious winds.
Baskiñas recommends that trees with needle-like foliage, spherical canopy-structure, deep root systems, and strong wood should be replanted in areas that are typhoon-prone or high in elevation.
4. Prune trees to encourage good branch angles.
Careful pruning helps trees survive strong winds. Trim rotting branches to develop a sturdy framework around a strong trunk. Good branch angles are 10 o’clock and 2 o’clock. Let strong winds pass through freely, while still providing shade. “Pruning reduces the impact of strong winds and heavy rain on leaves and branches,” notes Baskiñas.
5. Choose trees with strong root systems.
Trees with shallow, fan-like roots are less-resistant to strong winds than those with deep root systems. Plant trees away from utilities and buildings to minimize risk.
Keen observers might have noted that many Acacia trees were felled by Typhoon Glenda. Baskiñas explains that the diameter of an Acacia’s canopy is very wide, which translates to more pressure on the main trunk. Too much pressure can topple trees.
6. Toppled trees can still survive.
Small trees may be righted or replanted if their root systems are relatively intact. Cover or moisten exposed roots, dig a pit around the toppled tree, then carefully push the tree back to its upright position. Ensure that all roots are covered in soil and prune the majority of branches to encourage regrowth. Baskiñas says some damage can be treated with tree surgery, while some trees can heal on their own.
7. Contact your electric company to ask for assistance in cutting off tree branches that interfere with power transmission lines.
Trees whose branches obstruct electric wires increase the risk of power outages and even fires during storms. The Manila Electric Company (MERALCO) deploys teams to trim tree branches.
Managing the Impacts of Storms
We face a climate-defined future. More extreme weather events and tropical cyclones like Yolanda and Glenda will come to batter the Philippines – toppling not just trees but development successes which have taken decades to achieve.
Like trees, we must learn how to bend with the wind and grow roots that enable us to withstand the tempest.
We also have to manage our environmental footprint. WWF and the Global Footprint Network’s 2012 report reveals that humanity’s footprint is 50% beyond sustainable levels. The Philippine footprint has overshot its limits by 117%.
A 2013 Laguna Lake Development Study also showed that though Metro Manila generates 0.05 global hectares per area (GHA) of resources, it consumes 1.7 GHA. Manila is thus 3400% beyond sustainable limits. Our ecological footprint, coupled with the mismanagement of our environment and poor urban planning, aggravates the impacts of climate change and increases our vulnerability.
Concludes WWF-Philippines Vice-chair and CEO Jose Ma. Lorenzo Tan: “Trees have adapted to life in forests and plains – not in cities. In a climate-defined future, managing what trees we plant in our cities can greatly reduce our vulnerability to typhoons. This will save human lives and keep vital lifelines – like power and communications – humming and running during the most ferocious storms.”