On a humid November morning in Siboro, a village tucked inside the rugged limestone corridors of the Kebumen Geopark, Central Java, Mar’atun Chasanah moved briskly between seedling trays at a modest tree nursery.

For the past seven years, the manager of the Bumi Hijau Lestari Foundation’s Kebumen unit has been responsible for coordinating thousands of tree plantings each year across one of Java’s driest, most geologically complex landscapes.

Her work is quiet and largely unseen, but it has changed the texture of the land. “Every year, at least 100,000 trees are planted in Kebumen. Last year, we had 300,000 trees planted. These are barren and critical lands, so farmers are very eager to plant,” Mar’atun spoke to Indonesia Business Post on Sunday, November 23, 2025.

Founded with the mission of ecological restoration and community-based conservation, the Bumi Hijau Lestari Foundation (YBHL) works in several provinces, but its efforts in Kebumen sit at the intersection of conservation, agriculturaland rural livelihoods. The area is part of the UNESCO endorsed geopark network, a landscape dominated by karst hills, thin soil and a population heavily reliant on smallholder farming.

Here, YBHL’s tree-planting program is not just about adding green to the map, it is about reshaping long-term survival strategies.

Since YBHL began working in the area in 2008, thousands of farmers have participated. The collaboration model is simple: Farmers volunteer their own land, YBHL supplies seedlings and technical support, and field facilitators monitor growth.

There is no coercion. “We never force farmers. If they’re not interested, they need not join. Our base is willingness,” Mar’atun said.

That approach appears to work. From Karanggayam to Sadang, enthusiasm has grown steadily. Each year, around 500 farmers in Kebumen alone participate, cultivating plots that range from small home gardens to multi-hectare slopes.

Women farmers are included too, Mar’atun emphasized. “As long as they want to plant, they join, women or men.”

The species planted reflect the needs of the local landscape: teak, sengon (albizia), jabon (burnflower), gmelina and gamal (Gliricidia) for timber or fodder, and fruit species like mango, durian, and avocado for longer-term income. In the geopark’s highland areas, where livestock is common, fodder trees are critical.

A farmer’s calculation

For farmers like Imam Saefuddin, who lives in Siboro, timing is everything. Imam is a new participant, barely a month into the program. Sitting on his motorbike while waiting for a fertilizer vendor, he cited that local agricultural rhythms follow the Javanese mangsa calendar, an old system of seasonal calculation that dictates when to prepare land and when to plant.

“The best time is now, in the planting season. If planting islate even by two months, trees will not grow the same height. Wood needs the right start,” Imam said.

The foundation told farmers that seedlings would arrive in January. That, Imam noted, is slightly off the ideal cycle. Still, he hopes to plant balsa or albizia on his quarter-hectare plot.

“I already have many trees, but when support is coming, certainly I’ll join,” he said.

Coordinating the exchange between the foundation and dozens of farmers is the job of facilitators, like Nur Setyo Wasis, who has worked as a Field Facilitator (FF) for five years.

His jurisdiction ‒ Siboro and a cluster of nearby villages ‒requires him to manage everything from farmer registration to monitoring plant survival, distributing seedlings, and reporting progress up the chain to his team leader.

“Every year the target is different. This year, 5,210 seedlings for my area. Across three FFs, that will be around 15,000,” Nur said.

Challenges, he admitted, mostly revolve around timing. Seedlings must be strong enough before distribution, yet farmers want planting to coincide with the rains.

“If seedlings arrive too late, mortality increases,” Nur said. In some years, more than half the seedlings survive; in others, unpredictable shifts in rainfall patterns hit harder.

Still, farmer participation continues to climb. “At first they were afraid we’d ask something back from them,” Nur recalled.

“After seeing that everything is free and beneficial, interest increased a lot. This year we even had to limit the number of participants,” Nur added.

Across provinces, rooted in communities

While Kebumen is among YBHL’s most active sites, the foundation also works in Bali, West Java and Cilacap, where it focuses on mangrove restoration. Kalimantan was once under consideration, but plans shifted, with expansion redirected to West Java’s Sumedang region.

Wherever it operates, the foundation follows a principle: hire local people, work with local farmers.

“Our headquarters may be in Semarang, but staff are always from the area they serve. People who understand the landscape and the community,” Mar’atun said.

In Kebumen, that intimacy with the land is essential. The geopark is a place where soil is thin, rain patterns are erratic, and agricultural margins are narrow. Yet it is also a place where farmers still rely heavily on collective knowledge and deeply rooted ecological intuition.

Reforesting a future

Driving through Siboro today, the landscape is a patchwork of young teak and fruit saplings, scattered between corn stubble and limestone outcrops. They do not transform the land overnight, but the community is betting on what those trees will become 10 or 15 years from now.

For Imam, planting trees is less about environmental idealism and more about legacy.

“If the seedlings come late, yes, they grow slower, but trees are long life. We plant what we can now,” Mar’atun stressed.

For Mar’atun and her team, that is reason enough to keep going. “Restoration is not a one-time project, it’s a partnership with the people who live here,” she said.

In the karst country of the Kebumen Geopark, such partnerships may be the most enduring thing of all.