BONN, Germany (Landscape News) — It is hard to imagine that the lush forest of Haller Park, an ecological wonder in East Africa, was an arid wasteland just a few decades ago.
Spurred by modern urban society’s insatiable demand for cement, the binding element in both concrete and mortar, in the early 1950s Swiss company Cementia Holding built a factory on the outskirts of Mombasa, Kenya’s second-largest city.
At two nearby quarries on the north coast, men and heavy machinery mined for limestone. They bulldozed the topsoil to expose hard rock, which was cut into multi-ton blocks—and then transported to the crushing and processing plant.
Over the years, cement production at the local quarries grew from 1.2 million tons annually to 25 million tons. But the once-fertile area soon became a barren landscape with brackish ground water.
In 1970, Bamburi Cement Ltd., founded in 1951 as a partnership between Cementia Holding and Blue Circle in British Kenya, decided to convert the disused limestone quarries into a vibrant and diverse ecosystem of forest, grasslands and ponds. The company, now a subsidiary of international giant LafargeHolcim, and the leading cement manufacturing and marketing company in the East Africa region, assigned Swiss agronomist Rene Haller to the task.
The stunning reclamation project began with a hardy tree and a hungry insect.
As the long-time manager of Bamburi Cement’s garden department, Haller set out to find pioneer plants that could thrive in the abandoned quarries baking under a fierce tropical sun. Of the first 26 plants he experimented with, only three survived: The damas, coconut palm, and the casuarina.
The casuarina has adapted to grow under severe conditions. Its branchlets resemble pine needles and have a strong outer surface that protects the tree against water loss. The casuarina could tolerate brackish water, which seemed perfect for the environment. However, due to the tree’s high tannin content, its needles are too tough and bitter to be broken down by bacteria into humus.
Having observed a red-legged millipede feeding on dry casuarina needles, Haller introduced hundreds of millipedes into the old quarry. Their droppings while feeding on the casuarina needles, made it easier for bacteria to break down, resulting in a rich layer of humus for other plant species to grow in.
After five years, the casuarina began self-seeding and colonizing the surrounding area. After 10 years, the trees reached a height of 30 meters. After 20 years, some of the trees had a trunk circumference of 2.4 meters and the humus layer was 10 cm deep. Many of the trees began to collapse after two decades, but not before accomplishing their task and creating a friendly environment for new plants.
Fauna was later introduced into the area. Insects and other animals proved important for a new ecosystem through pollination and seed dispersion. The experiment worked for the first 2 square kilometers. Replanting of native species of trees began in 1989 and was fast-tracked in the nineties.
“By the year 2000, many indigenous plant species had been established,” says Albert Musando, the ecosystems and tourism manager of Lafarge EcoSystems, a subsidiary of Bamburi Cement. “Thirty species of mammals and 180 species of birds resided in the reclaimed quarry. The majority of the animals brought here were either orphans or rescued animals.”
Today, Haller Park is a popular tourist attraction as well as an important site for education. The park consists of a game sanctuary, reptile park, small demonstration fish farm area, palm garden, crocodile pens and a giraffe viewing platform, offering a variety of attractions to educate and entertain the more than 160,000 paying visitors to the site every year.
Water played an important role in the economic and ecological development of the project. The aquaculture system at Haller Park is commercially viable. The unit consists of the fish farm, crocodile area, and the biological water treatment area (Nile cabbage ponds and rice paddy fields). The Nile cabbage is a special plant that removes excess nutrients and impurities from the body of water.
Nearby, another old quarry has been transformed into the Bamburi Forest Trails, first opened to the public in 1997. The trails cover a wide area of Bamburi Quarries, some already rehabilitated while other sections are still barren or in early stages of reforestation.
They initially started as a “one million tree project” in 1986 along the stretch between the Bamburi cement plant and the Shanzu suburb of Mombasa. Mining in this area was only four meters deep.
There are four nature routes in the Forest Trails for cycling, jogging, walking and fitness. A 3.6 km leisure walk enables visitors to experience alternating landscapes from empty quarries to lush forest, lakes, streams, palm groves and plantations of indigenous trees. The integrated wetland system provides an enabling environment for the increase of surrounding biodiversity.
Sunis and Duiker antelopes, Eland and Oryx are some of the animals you come across in the forest.
In committing millions of dollars and decades of man hours to land reclamation, Bamburi Cement was ahead of its time.
Sabine Baer-Visram, biodiversity consultant at Lafarge EcoSystems, says that in the 1970s, “there was no environmental legislation in place, and awareness of environmental issues was still in early stages.” Now, following the passing of the Environmental Management and Coordination Act of 1999, it is a legal requirement for mining companies in Kenya to rehabilitate spent quarries and restore them to a usable state.
Lafarge EcoSystems, says Chief Operating Officer Mary Mueni, has also developed environmental education programs designed to improve learner experience, and the company entered into a partnership in 2016 with Pwani University north of Mombasa to support environmental research for its students. Other collaborative partnerships include the Kenya Wildlife Service and the Kenya Forest Service for research on quarry rehabilitation, biodiversity management and environmental education.
Last year, Bamburi Cement suspended plans to switch to solar power because of the high cost of the project. Director of Corporate Affairs and Sustainability Susan Maingi says that instead, the company opted to utilize waste tires with support from recycling firm Geocycle, a project that has been incorporated into the cement firm’s sustainability agenda to safeguard the environment.
“Basically, we still need electricity to turn the machines but it has reduced some costs when it comes to other alternative forms of energy that are required to produce heat,” says Maingi. To do this, Bamburi turned to worn out tires and agricultural wastes like coffee and rice husks. So far, the company has managed to recycle at least 400,000 tonnes of tires to produce energy at its factories.
Mining for limestone is a destructive enterprise. But Bamburi Cement has shown that vision, sheer will and innovative natural solutions can reclaim landscapes lost to human development.
Find out about upcoming Global Landscape Forum 2018 Nairobi summit: Landscape Restoration in Africa: Prospects and Opportunities