THE LOSS of mature trees along Quirino Avenue could aggravate flooding and urban heat in Manila and trigger a “domino effect” on air quality, biodiversity and public health, a UST biologist warned.
Amid recent flooding in Metro Manila caused by the southwest monsoon, or habagat, Asst. Prof. Melanie Arbias of the Department of Biological Sciences stressed the role of mature tree canopies in absorbing rainfall and regulating temperatures in highly urbanized areas.
Tree-cutting operations began in May after the Department of Environment and Natural Resources (DENR) issued a special permit covering 617 mature trees between Quirino Avenue and Roxas Boulevard.
The clearing was undertaken to make way for the elevated four-lane Quirino segment of the 40.6-kilometer Southern Access Link Expressway.
Arbias said the removal of mature trees could worsen flooding in the area and intensify heat during hotter months, while affecting air quality and local biodiversity.
“What’s critical in terms of the presence of mature trees in Quirino is that, ilan na lang ‘yung mga mature trees sa City of Manila,” Arbias told the Varsitarian.
(What is critical about the presence of mature trees along Quirino Avenue is that there are only a few mature trees left in the City of Manila.)
“Since kakaunti na lang talaga din sila, lalong-lalo na ‘yung malalaking puno talaga, so kailangan talaga natin silang i-maintain. Actually, dapat nga paramihin pa ‘yung green spaces,” she added.
(Since there are already so few of them, especially the large trees, we really need to maintain them. In fact, we should expand green spaces further.)
Earth-UST President Sophia Padua likewise stressed the importance of having the appropriate trees in urban environments, particularly for air quality and public health.
“Trees are like a natural filter for our air quality, and the type of tree matters because it cannot just be any kind of tree. If it is not suitable for its environment and the infrastructure around it, it can also pose a threat to public health,” Padua said.
Ecological domino effect
Arbias warned that the effects of losing mature trees could extend beyond flooding and heat because human, animal and environmental health are interconnected.
She called for a “One Health” approach to development rather than pursuing projects without fully considering their effects on ecosystems.
“The health of humans, the health of animals, the health of the environment, they are interconnected and interrelated with one another,” Arbias said.
She said the loss of mature trees could degrade soil quality and fertility and reduce water retention and the availability of nutrients needed to sustain plant life.
The effects could extend to animals that depend on trees and other vegetation for food and habitat, she added.
“Marami tayong interesting na mga fauna that depend on trees or plants,” Arbias said. “So, posibleng mag-migrate sila o kung hindi makaka-adapt, mamamatay at bababa talaga iyong population.”
(We have many interesting fauna that depend on trees or plants. So, it is possible that they will migrate, or if they cannot adapt, they will die and their populations will decline.)
Arbias said disruption of local biodiversity and the displacement of wildlife could also push animals into human settlements, potentially increasing the risk of zoonotic diseases, or diseases transmitted between animals and humans.
As a mitigation measure, project proponent San Miguel Corp. has committed to planting 50,000 seedlings to replace trees felled and earth-balled along Quirino Avenue.
But Arbias, a member of the Philippine Native Plants Conservation Society Inc., said seedlings could not immediately replace the ecological functions performed by mature trees.
“Kahit na 100,000 pa ‘yung ipalit mong seedling diyan, kailan pa sila lalaki?” she said.
(Even if they plant 100,000 seedlings there, how long will it take for them to grow?)
Arbias said protecting existing mature trees was particularly important for conserving native species.
“Unfortunately, walang makakapalit sa ecological roles ng trees and plants,” she said.
(Unfortunately, nothing can replace the ecological roles of trees and plants.)
Padua likewise stressed the value of mature trees in heavily built-up areas.
“Trees are really vital to our community as they provide oxygen, they provide quality air. They’re a natural barrier to flooding, and they also bring life to the urban city,” she said.
‘Tip of the iceberg’
For Arbias, the tree removal along Quirino Avenue reflects the broader tension between urban development and the preservation of natural ecosystems.
She described the tree-cutting and earth-balling along the avenue as only the “tip of the iceberg” and called for science-based sustainability measures to accompany economic development.
“Maraming reclamation projects na nangyayari sa mga natural ecosystems pa. ‘Yung urban green spaces, kailangan natin sila kasi nga kakaunti na lang sila, so dapat talagang i-protect,” Arbias said.
(There are many reclamation projects taking place in natural ecosystems. We need these urban green spaces, especially because so few of them remain, so they really need to be protected.)
She also cited development pressures on wildlife habitats, including the proposed relocation of the Las Piñas-Parañaque Wetland Park.
“Gusto pa natin ‘yung mga ibon ang mag-adjust para sa atin,” Arbias said.
(We even expect the birds to adjust for us.)
Padua said nature should be treated as an integral part of cities rather than something that could simply be removed to accommodate development.
“I don’t think an urban area can properly function without nature in it because we are simply living in nature,” she said. “I don’t think you can take nature out of its home. You can only live in it.”
Citizen science
Arbias urged communities to take part in citizen science and conservation activities to deepen public understanding of biodiversity.
“Pwede pa rin tayong tumulong sa conservation at ma-appreciate ang ganda at kahalagahan ng biodiversity by being actively involved or mag-initiate ng tree walk activities, nature walk activities, and bird watching activities,” she said.
(We can still help in conservation and appreciate the beauty and importance of biodiversity by becoming actively involved or initiating tree walks, nature walks and bird-watching activities.)
“‘Yung maliliit na effort natin to conserve what we still have in terms of biodiversity, importante ‘yon,” Arbias added.
(Our small efforts to conserve what we still have in terms of biodiversity are important.)
Padua said Thomasians could contribute through environmental awareness, education and individual practices.
UST has its own “green” initiative discouraging students from using single-use plastics.
“The youth can contribute to this by practicing green habits on their own, and if they don’t know how, [they can] learn how to practice green. The resources are always available online,” Padua said.
San Miguel had felled and earth-balled 225 trees along Quirino Avenue before suspending the operations amid public backlash.
The DENR has not issued an extension or a new permit since the previous permit expired on June 24. Bernadette E. Alpas
