Above – Orchids – indigenous to Kenya at Brackenhurst in Limuru – Iphone
Copyright Mark Nicholson
Published Nation newspaper Saturday magazine 21 April 2018
“Africa and Madagascar were joined like this,” demonstrates Dr Mark Nicholson of Plants for Life and the person who has recreated the natural forest at Brackenhurst Botanic Garden in Limuru as a model to show that indigenous forests can be restored after removing plantations of exotic trees.
He has his fist in the open palm of his hand. The clenched fist is Madagascar and the palm Africa at the time when the supercontinent Gondwanaland existed. It began to tear apart some 175 million years ago at a time when dinosaurs still ruled the land.
The forest man is surrounded by a group of eager-beavers lapping up his every word in amazement.
We’re in the part of the forest where none of us have ever walked in. It’s the first section that was restored and the undergrowth is bursting with life, colour and intrigues.
We’re by a tall African relative of the pawpaw tree and the story of Gondwanaland is related to the story of the Pawpaw.
So here’s what happened:
“The pawpaw family (Caricaceae) originated in Madagascar,” explains Nicholson, “and drifted across Africa before getting into South America when all three land masses were connected.”
As he pulls his fist from his palm, he continues, “The family then radiated in South America into 47 different genera over tens of millions of years (including the real pawpaw, Carica papaya) leaving behind a bit of DNA in Africa which became two tree species, Cylicomorpha parviflora in East Africa and C. solmsii in Gabon.
At this point we’re looking at what was once just a pawpaw tree with new-found respect.
Nicholson continues. “Cylicomorpha is a huge tree that reaches (hold your breath) more than 40 meters (130 feet) and the only genus of the pawpaw family native to Africa.”
OMG … there are sudden bursts of wonder from the crowd.
Anyway, the tree is from a little known hill called Kiang’ombe in South Embu with a few others in the forest around Meru. It has never been grown in a collection in Kenya so Nicholson is waiting for it to fruit for the first time so he can raise some more. Like several tree species, the trees are either male or female, so to get seed one needs several specimens to ensure one has both genders.
It’s proving to be a really fascinating walk under the forest canopy carpeted with leaf litter, like opening an exciting book turning page after page because everything is so gripping.
It’s an unexpected bonus to have met Nicholson just as we were watching a young African Harrier Hawk on the roof of a building screaming for its mother and then watching the adult fly in. The youngster spread its wings and like a human child taking its first steps, flew with wavering wings into the air following the adult.
Every few steps we stop to admire the many different plants in the forest. A show-stopper is a richly-laden moss covered tree with five different kinds of indigenous orchids, some in flower.
So hold your breath again. There are more than 20 species of orchids in the forest lavishing in the healthy clean air as are the many patterned ferns, lichens and algae.
“This is all part of biodiversity,” continues our forest guide. “A eucalyptus, wattle or cypress ‘forest’ plantation has very little happening in it in terms of biodiversity.” They are all exotic trees for harvesting like any crop on a farm.
“Ours is a planted forest too but with very high biodiversity because the trophic levels establish themselves naturally.”
Someone asks what that means.
“A trophic level is an ecological term where one species depends on another, like a dudu which eats the leaf; a larger dudu eats the smaller dudu; a bird eats the big dudu; a hawk eats the small bird. A bushpig eats the fungus that depends on the fallen branch of a tree and so on.” All these are trophic levels.
Ah ha! We’re all feeling smarter with more new found knowledge.
Nicholson stops by a huge euphorbia that we all think is a cactus. But the truth of the matter is that cacti are not African plants except for one indigenous kind – Rhipsalis baccifera – and in a departure from the normal cactus, this one has no spines and grows like an epiphyte on the higher branches of trees as we see in the botanic garden – and nicknamed misletoe cactus.
Back to the euphorbia – nearby is another rare one from Ukambani called E. cussonioides.
The ground is covered with puffballs of flaming red forest flowers and of course it’s the indigenous forest lily Scadoxus multiflorus.
It’s an amazing walk. With more than 500 plants in the forest, there’s no way one can see everything in a day. Besides the plants there’s wildlife in it like the three kinds of owls- Wood, Barn and Spotted Eagle Owl, plus hedgehogs, Colobus monkeys, eagles and so much more.
The walk, the fresh air and the exciting bits of information will have us returning for more.
For more log on brackenhurstbotanicgarden.org