Why Replacing a Mature Tree Is Not as Simple as Planting a New One

There are moments when city life reminds us that comfort is not always something we notice until it is gone. A shaded sidewalk. A cooler waiting area. A street that feels less harsh at noon. A row of trees that makes the walk home feel softer, even when the traffic is loud and the air is heavy.

That is why the tree-cutting issue along Quirino Avenue in Manila felt personal to many people. According to the Philippine Daily Inquirer report provided, the Department of Environment and Natural Resources said the cutting of trees for the Southern Access Link Expressway project had been temporarily paused for further study. Environmental groups welcomed the pause, but also questioned why the review came only after more than 200 trees had reportedly already been cut.

Photo: Elmer Valenzuela

At first, the usual answer sounds simple: cut one tree, plant another. Or plant five. Or plant ten.

But trees do not work like furniture. You cannot remove an old one, place a young one somewhere else, and expect the city to feel the same by next week.

A mature tree is not just one tree. It is shade, cooling, roots, soil, habitat, memory, and time. It has spent years growing wide enough to cover a sidewalk, strong enough to hold rainwater, and rooted enough to become part of the street’s small ecosystem. A sapling may become valuable one day, but it cannot immediately do what a mature tree does now.

Research on urban trees and heat shows why age matters. One study on street trees found that very young trees provide little heat relief during extreme heat, while trees around 30 to 60 years old perform much better in cooling pedestrian areas. In simpler terms, a young tree is a promise. A mature tree is already doing the work.

Photo Credits: ABS CBN

This matters even more in cities like Manila, where heat is already part of daily life. Trees cool streets in two main ways. First, they give shade, which protects people and pavement from direct sunlight. Second, they release water vapor through their leaves, which helps cool the surrounding air. A recent report on global urban heat found that trees help reduce city heating, but also noted that not all cities benefit equally, especially hotter and poorer areas with less green cover.

That means tree loss is also a quality-of-life issue. It affects commuters, vendors, students, workers, elders, children, and anyone who has to move through the city without the comfort of air-conditioning. A street without shade is not just uglier. It can be hotter, harder to walk through, and less humane.

There is also the issue of rain. Mature trees help catch rainwater before it hits the ground all at once. Their roots help soil absorb water better. Their canopies slow down runoff. In flood-prone cities, this matters. When trees are removed and more concrete is added, rain has fewer places to go.

Then there is the part we do not see: the underground world. Tree roots connect with fungi, bacteria, and other soil life. Research on tree species and soil communities shows that different trees help shape different underground ecosystems. When an old tree is removed, the loss is not only what disappears above ground. Something living below the pavement changes too.

This is why “tree planting” is not enough when it is used as a quick excuse. Tree planting is good. Cities need it. But planting must be paired with protection, planning, maintenance, and transparency. Otherwise, it becomes a photo opportunity instead of a real climate solution.

Other cities show that better planning is possible.

Melbourne, for example, has worked toward a long-term urban forest vision, including a goal of increasing canopy cover and turning more gray spaces into green ones. Reports have discussed the city’s effort to create new parks, improve open spaces, and plan around urban heat instead of simply reacting to it.

Singapore offers another lesson. Its Heritage Trees Scheme recognizes that some trees are important not only because they are alive, but because they are part of a place’s identity. These are mature trees selected for their size, age, history, and significance. The point is simple: some trees should be protected before development decisions are made, not mourned after they are gone.

New York City also approached urban greening as a long-term public project. Its MillionTreesNYC program planted one million trees across the city through a partnership between government and civic groups. But the important part was not just the big number. It was the larger system: planting, mapping, neighborhood targeting, and community participation.

These examples do not mean that Manila should copy another city exactly. Every city has different roads, budgets, climate risks, and public needs. But they show a better way to think. A city should not count trees only after they are cut. It should know what trees it has, where they are, how old they are, what species they are, and what role they play before any major project begins.

For Manila, the question should not be “How many saplings can replace the trees?” The better question is, “How much shade, cooling, flood protection, biodiversity, and public comfort were lost, and how will those be restored over time?”

Because a mature tree is not replaced by a number. It is replaced only by years of care, enough soil, the right species, regular watering, survival checks, and a serious promise that the next generation will not inherit hotter, harsher streets.

Progress does not have to mean a city with fewer trees. Roads, transport, housing, and infrastructure matter. But so do the things that make a city livable once people step outside.

A tree is not just something beside the road. Sometimes, it is what makes the road bearable.