For Rajan Thombre, a resident living at the foothills of Vetal Tekdi in Kothrud, the hill has long been an extension of his neighbourhood. It is where residents gather every evening to walk, exercise and spend time outdoors.

That routine has begun to change. "The hill used to cool much earlier. Now the rocks hold the day's heat well into the evening. Before we sit, we pour water on the ground to make it bearable.", Thombre says.

Retired forest officer Mr. Ashok Khadse, who has lived near the hill for decades, has noticed similar changes. Summers stretch longer, trees remain stressed before the monsoon and wildlife appears less frequently than it once did. His wife, Ms. Savita , remembers a time when native trees such as neem and amla were common enough for residents to use them for medicinal purposes.

Their observations reflect what researchers are now documenting.

Pune has witnessed hotter summers, warmer nights and increasingly erratic rainfall over the past decade. A study led by Dr. Pankaj Koparde found that between 2013 and 2022, the city's carbon sequestration capacity declined by 34%, while its flood mitigation capacity fell by 13%. During the same period, built-up areas expanded by 12%, replacing scrublands and other natural landscapes that once absorbed heat, stored carbon and slowed stormwater.

The transformation is also visible in the city's landscape. A World Resources Institute (WRI) assessment found that between 2016–17 and 2019–20, Pune lost nearly 620 hectares of tree cover, while built-up land increased by 839 hectares. Grasslands shrank by almost 500 hectares, reducing the city's natural capacity to regulate temperature, absorb rainwater and support biodiversity.

As Pune warms, its remaining hills are expected to do far more than provide green cover. They cool neighbourhoods, recharge groundwater, store carbon, support biodiversity and reduce the impacts of extreme weather. Urban forests have become part of the city's natural climate infrastructure.

Tree plantation has become one of Pune's most visible responses to a warming climate. Every monsoon, the Pune Municipal Corporation (PMC), the Forest Department, citizen groups and corporate CSR initiatives plant thousands of saplings across hills, roadsides and public spaces. This year, the PMC announced a target of planting five lakh trees across the city to expand its green cover.

Yet the success of afforestation is proving harder to measure than the number of saplings planted.

Questions raised in the PMC's General Body and information obtained through Right to Information (RTI) applications reveal that while the civic body maintains records of plantations, it does not have consolidated survival data for many of them.

Between April 2024 and April 2026 alone, the PMC reported planting 17,533 trees under compensatory afforestation, but acknowledged that it could not provide a consolidated account of how many had survived. A separate RTI filed by civic activist Vivek Velankar also revealed severe vacancies in the Garden Department's supervisory staff, raising concerns about the city's capacity to monitor plantations after they are completed.

For Rajan Thombre, the gap is visible on the ground.

"People come during plantation drives," he says. "After that, no one comes back to see whether the trees survived."

"At present, we consider a plantation successful when at least 60% of the planted saplings survive. The Forest Department provides care for the first five years, including fencing, manure and human support, after which the trees are expected to establish and survive on their own. However, parameters such as native species regeneration, biodiversity, soil health and canopy diversity are not yet being considered before plantation." — Abhijit Waykos, Deputy Conservator of Forests (DCF), Pune Division

The distinction is significant. A plantation can meet a survival threshold without necessarily developing the diversity and regenerative capacity of a functioning forest.

"Plantation gives an easy dopamine because it offers an immediate sense of achievement. Ecological restoration doesn’t work that way. The real work begins after the plantation drive is over." — Environment Journalist & Researcher, Ecological Society

The city's plantation drives reflect a broader shift in the role of urban forests. Once viewed primarily as a way to restore degraded hills and increase green cover, they are now expected to cool neighbourhoods, support biodiversity, store carbon and help cities cope with rising temperatures and erratic rainfall.

Whether today's plantations can deliver those benefits, however, remains a question that extends beyond the number of saplings planted.

GoToday, walking through the hill tells a different story. From a distance, Vetal Tekdi appears densely forested. A closer walk reveals long stretches dominated by Gliricidia sepium, punctuated by scattered neem, gulmohar, eucalyptus and a handful of other species. The landscape reflects restoration choices made decades ago rather than natural forest succession.

By the late twentieth century, years of grazing, fuelwood extraction and soil erosion had left many of Pune's hills exposed and unstable. The immediate priority was to arrest further degradation and restore vegetation cover before ecological recovery could begin.

According to restoration practitioner Ameet Singh, the expectations from these hills have evolved with the changing climate. "Those plantations addressed the ecological priorities of their time. Today, as the climate changes, the expectations from those same landscapes have changed as well."

When these restoration programmes began, success was measured by how quickly vegetation could return to degraded hillsides. Under Maharashtra's Social Forestry Programme, Gliricidia sepium-a fast-growing, nitrogen-fixing tree native to Mexico and Central America-became one of the preferred species because it established rapidly on poor soils, reduced erosion and improved soil fertility.

Retired forest officer Ashok Khadse, who was associated with forestry work during that period, says the objective reflected the needs of that time. "The objective was to green barren hills as quickly as possible. Climate resilience was not part of the discussion."

The approach transformed many of Pune's barren hills into green landscapes. Decades later, however, those same landscapes are expected to perform a wider range of ecological functions-cooling neighbourhoods, supporting biodiversity, storing carbon, recharging groundwater and remaining resilient under a changing climate.

Whether they can meet those expectations is becoming one of the central questions in urban forest restoration.

"Earlier, there were more native trees like neem and amla. People from the neighbourhood even used them for medicinal purposes," says Savita Khadse, who has lived beside Vetal Tekdi for decades.

From the foothills, Vetal Tekdi appears as a continuous stretch of green. A closer walk reveals a different pattern. Large parts of the hill are dominated by Gliricidia sepium, while native trees appear only intermittently-an ageing neem, scattered gulmohar, eucalyptus and a handful of other species. The hill has gained canopy, but much of its ecological diversity has thinned. The changes extend beneath the canopy.

A caretaker responsible for maintaining plantations on Vetal Tekdi, who requested anonymity because he was not authorised to speak to the media, says the hill's soil has deteriorated noticeably over the past decade. "The soil is not what it used to be," he says, explaining that newly planted saplings now struggle to establish where they once survived more easily. During summer, he adds, even the shade offers limited relief. "We often have to sit inside the watchman's room because it is cooler than resting under the trees."

For restoration ecologist Dr. Ketaki Ghate of Oikos Ecological Services, the observations reflect a broader ecological challenge.

"Gliricidia is an efficient species if the objective is to quickly create canopy cover or accumulate carbon, But climate resilience goes beyond tree cover. It is about rebuilding ecosystems." She says

Ghate explains that Pune's hills naturally support a mosaic of tropical dry deciduous forests and tropical shrub-savanna vegetation, where native trees, shrubs and grasses perform complementary ecological functions. Native grasses protect exposed rock from direct solar radiation, retain soil moisture and create conditions for natural regeneration, while diverse tree species provide habitat for birds, insects and other wildlife.

Research carried out by Gour University suggests that where Gliricidia becomes dominant, those processes may slow. Its leaf litter contains allelopathic compounds that inhibit the germination and early growth of neighbouring plants, while dense stands reduce opportunities for native seedlings to establish.

Although the species accelerates biomass accumulation and carbon sequestration, ecologists caution that forests dominated by a single fast-growing species lose native vegetation faster than anything

Every summer, ecologist Dr. Raghunath Dhole visits Pune's hills to collect seeds from native trees before the monsoon. Some seeds are picked from the ground beneath mature trees, while others are recovered from bird droppings after dispersal. The seeds are cleaned, catalogued and preserved for future restoration.

The work depends on timing. Trees flower, fruits mature and seeds fall within a short seasonal window. For years, Dhole says, those patterns remained fairly predictable.

"Ten years ago, we knew when flowering would begin and when seeds would mature. Today, it is becoming increasingly difficult to predict," he says.

The shift became apparent while monitoring Palas (Butea monosperma), a characteristic tree of Pune's dry deciduous forests. In previous years, Dhole's team routinely collected thousands of Palas seeds. This summer, they found only a fraction of that number.

Repeated observations pointed to an unusual pattern. Birds were consuming developing seeds along with the remaining fruits before they reached maturity.

For Dhole, the change reflects more than a failed seed collection season.

Native birds depend on a succession of flowering and fruiting trees throughout the year. As climate variability alters flowering cycles and native diversity declines, those seasonal food resources become less reliable. Changes in bird foraging behaviour, in turn, influence seed dispersal-one of the primary mechanisms through which forests regenerate.

"Climate change doesn't only affect the forests we see today," Dhole says. "It affects the forests that are yet to grow."

The shift has already begun on Pune’s hills. Under its 2020–2030 Working Plan, the Pune Forest Department has identified 2,556 hectares of forest areas—including hills, wetlands and urban forest areas—for phased removal of Gliricidia sepium and its replacement with native species. The department has set an annual removal target of 250 hectares.

"Under the 2020–2030 working plan, we have identified 2,556 hectares for phased Gliricidia removal, with an annual target of 250 hectares. One of the major challenges in implementing the programme is the availability of labour." — Abhijit Waykos, Deputy Conservator of Forests (DCF), Pune Division

Replanting is taking different forms across Pune. At Taljai, the Forest Department is undertaking Miyawaki plantation, while other plantation drives have introduced native species such as Sarval, Chinch and Karvand, supplied by the department.

Yet replacing one species with another does not automatically restore an ecosystem. Parameters such as native species regeneration, biodiversity, soil health and canopy diversity are still not being considered before plantation, according to the Forest Department.

The transition, however, raises questions that extend beyond replacing one species with another. Can native forests recover after decades of ecological change? How should invasive stands be removed without exposing fragile hill slopes? And can restoration succeed if native species, which often require years of care and ecological support before establishing, are treated like conventional plantation drives?

For restoration practitioner Ameet Singh, the answer lies in investing beyond plantations.

"Plantation is the most visible part of restoration, so it naturally attracts attention and resources. But building resilient forests requires investment before and after trees go into the ground."

He argues that ecological restoration should be supported through sustained funding for botanical gardens, forestry and agroforestry institutions, horticulture colleges, native plant nurseries and organisations working on ecological restoration.

Long-term ecological surveys, species suitability assessments, seed conservation, native germplasm development and post-plantation monitoring, he says, are just as important as the plantation itself if cities hope to rebuild forests that can withstand a changing climate.

But restoring degraded hills is only one part of building climate resilience. Ecologists at Oikos Ecological Services argue that protecting the ecosystems that remain is equally important. Pune’s rapidly expanding construction footprint is putting increasing pressure on hill slopes, open spaces and existing tree cover, making protection and restoration two sides of the same ecological challenge.

They call for greater coordination between the Forest Department and other PMC departments so that development projects take the ecological value of these landscapes into account. They also stress the need to identify and develop ecologically sensitive zones across Pune to protect existing trees and hill ecosystems from fragmentation and further disturbance.

For restoration ecologist Dr. Ketaki Ghate, replacing exotic trees is only part of the solution.

"As cities look to forests for climate resilience, restoration has to move beyond planting trees," Ghate says. "The objective is to recover ecological processes that allow forests to regulate temperature, support biodiversity and regenerate on their own."

(This article is authored by Madhura Shelke, mentee of the Climate Change Media Hub at the Asian College of Journalism, Chennai. The programme is supported by Interlink Academy, Germany.)