By Rupi Mangat

For most people a forest is simply a bunch of trees.

In reality, there are different types of forests, ranging from indigenous forests, complex ecosystems providing essential services like biodiversity, clean water and air- to plantation forests, planted for a purpose and harvested young for timber and drying tea. Every four acres of tea requires one acre of eucalyptus to provide fuel wood to dry the tea leaves.

Nothing could be as dramatically different as these two forest types.

Seventeen years ago, the Brackenhurst Conference Centre and Botanic Gardens in Tigoni on the highlands of Limuru (25 kilometers northwest of Nairobi) amidst green-clad tea plantations stood non-native tree plantations of eucalyptus, wattle and cypress trees. Today, much of the 100 acres is covered by an unbroken canopy of trees native to Kenya.

Kenya’s Forests

In a scholarly paper presented in 2004, The Forest Types of Kenya, Piritta Peltorinne revealed that out of the country’s 582,646 square kilometres, 11, 230 square kilometres is open waters, and only 2,008 square kilometres (3.4 per cent) of the total land area is covered by forests. Out of this 3.4 per cent, 1,700 square kilometres is indigenous forests while the rest is plantation, mangrove or privately owned.

Now the Kenya Forest Service (KFS) has a new definition of forest which brings it up to more than seven per cent of the country. This however includes scattered bushland where canopy cover is only 15 per cent. The Director of Plants for Life at the Brackenhurst Botanic Garden, Mark Nicholson, defines a forest as 80 per cent canopy cover.

Restoring a Forest

“The landscape restoration project is a new concept,” states Nicholson. Concerned about aggressive “invasive” plants and exotic trees that were impoverishing soils, restricting the growth of native plants, and drying up the only stream in the valley, he approached his neighbours at Brackenhurst in 2000.

The management listened to his concerns and then asked him to do something about it. And that became his challenge, a 30-year restoration project.


Walking through the 17-year-old forest of the Brackenhurst Botanic Garden, it fits a forest definition of a continuous canopy of trees at least 10m (33 ft) tall. It’s alive with forest birds and other creatures within a collection of 500 species of native plants and indigenous trees including many hardwoods like Prunus africana, Podocarpus, Afrocarpus and Warburgia ugandensis. All of these trees were common a hundred years ago, but are now listed as vulnerable on the IUCN Red list of globally threatened species.

“A forest is more than trees: it also means the ferns, orchids, lichens, fungi and all the animals and birds.

“There was no undergrowth or biodiversity in the eucalyptus plantations,” recalls Nicholson. “Now we have Colobus and Sykes monkeys, bushpigs, civets, genets, bush babies, hedgehogs, chameleons, harmless snakes, and insects.

“Indigenous forests are vital for biodiversity and trophic levels,” says the forest whisperer.

“It’s amazing to see how fast these trees have grown,” comments Fleur Ng’weno of the East African Natural History Society (Nature Kenya) and Kenya’s most respected naturalist. “Conventional wisdom had it that indigenous trees grow too slowly, so fast growing non-indigenous trees were planted. But the Brackenhurst Botanic Garden proves that there are many indigenous trees that are also fast-growing.”

Said Mark Nicholson: “Seventeen years ago, I wrote a report to say that in 15 years the trees would be high enough to bring back our flagship species, the Colobus monkey and I was spot on because we now have a resident family.”

According to him, the whole country needs forest restoration because even though Kenya has the most diverse native forests in East Africa, they are highly fragmented. The pressure on forests is huge with infrastructure cutting through them, clearance for settlement and agriculture, while at the same time rural communities depend on them for basics like firewood, herbal medicines, water and more.

The Bonn Challenge

The Bonn Challenge is a global effort to bring 150 million hectares of the world’s deforested and degraded land into restoration by 2020, and 350 million hectares by 2030.

Launched in 2011 by world leaders in the city of Bonn in Germany, each country sets a target to restore its indigenous forests, known as landscape restoration, by 2020, taking a landscape approach to restoration to improve agriculture, mitigate the effects of climate change, alleviate poverty and improve the availability of water and energy.

Kenya’s target is to restore five million hectares (50,000 square kilometres) but “It is one thing to set a target and quite another to reach it”, says Nicholson. “Here we are restoring a model forest, showing how it can be done and that it takes decades and not three years.”

If this is done, it could be a model for Kenya’s many fragmented forests like the Taita Hills and thereby save endemic species like the Taita apalis and the Taita thrush from becoming extinct in the near future.


If you would like guided walks in Brackenhurst Botanic Garden send a request to Dr Mark Nicholson on:

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