NAMIBIAN NOTES 1: THE BUSH

In most of the world, "the bush" are words that suggest wilderness, adventure -? unspoiled, pristine nature. "The bush" is what we yearn for when the modern world becomes too much - a place our imagination clothes with fertile soils, tall trees, clear waters and a deep blue sky, sheltering a profusion of animals,miraculous in both their diversity and number.

But in Namibia, "the bush" is a curse.

That bush - an impenetrable thicket of encroaching thorny shrubs - covers many thousands of square kilometres of the country. Stop your car on any rise, gaze in any direction, and you will see the bush marching off, all-conquering, smothering everything.

Talk to the elders of any tribe - Herero, Himba, Germans, Ovambo, Afrikaner, Damara, Basters - and they will tell you the same thing: in their youth, those oceans of sharp thorns did not exist. The landscape they have invaded were endless seas of perennial grasses swaying in the wind, dotted with majestic trees, and grazed by a cornucopia of wildlife and livestock.

?What happened? What turned this gentle paradise into a prickly hell?

?The answer is distressingly simple: set stocking, or letting livestock wander at will.

?Namibia is divided into two areas of very different land use systems. The communal lands are where the vast majority of the population lives, almost all in the wetter north of the country. There, land cannot be bought or sold: it is allocated by traditional chiefs through leaseholds modelled on the English systems and mostly used by smallholders. But 1.6x more land is so-called title deed land: farms of vast scales, typically 3,000 to 10,000 hectares each, almost all owned by individual farmer families, and mostly growing beef and/or wildlife.

?When your farm is that large, your paddocks - called camps in Namibia - will be huge: hundreds of hectares each. And in each of those camps, you will let your livestock, together with all the passing wildlife - kudu and zebras, wildebeest and giraffes, and multitudes of gemsbok and springbok - wander at will. There are few lions to worry about, and lazy leopards - those that go for calves or sheep - rarely make old bones. So, for a minimum of effort, all that beautiful grass turns into beautiful meat - and beautiful cash.

?But slowly, the grassland changes. The animals go for the sweetest, tenderest, most palatable species - just as we focus on the things we prefer at a hotel buffet. These grasses, mostly perennial, gamely regrow after being grazed, sacrificing some of their root sugars in the process. But far from being able to grow back to their full height and restore their roots through photosynthesis, these fresh grasses are exposed to a mortal threat: that livestock, which is still around! It pounces on that sweet, sweet regrowth. Repeat a few times, and those most palatable of grasses die out.

But you might not notice this if you're not an observant grass farmer. It's just one species less in a sward rich with grass species.

The trouble is, the process repeats itself with the next most palatable species, then the next, and so on. After a decade or two, bare ground will have spread between the things the animals will not touch - those plants that are thorny, poisonous, too much trouble to bother with. And those decades' worth of animal urine and manure? Far from benefiting the disappearing grasses, that rich fertilizer is only benefiting the thorn.

?And what thorns! Camelthorn spikes can pierce tractor tires. A multitude of species will break through your boots. There's a reason why Namibian pickups, called bakkies, are often seen not with one, but with two spare wheels.

?With the disappearing grasses, it's not just the beef farmers that suffer, but all that rich wildlife, too. Most wild herbivores are browsers as well as grazers, but most will struggle to pick nutrition from between long thorns. And in many areas of bushland, it is one invasive species that dominates the whole landscape. Acacia mellifera may be great if you are a honey bee, but it's pretty lousy for everyone else.

?Desperate farmers have tried all sorts of things to master the bush. Some use aircraft to spray arboricides on their whole farm. Others try burning it away. Yet others use pairs of bulldozers pulling a heavy chain between them to flatten everything. And some invent machines that seem to come straight out of a Mad Max movie to roll the bush back - while leaving valuable trees in place.

The bad news, for farmers and wildlife alike, is, if that's all you do, it won't work. You'll get grass back for a few years, and then the process repeats itself. The palatable species disappear, the thorny species take over again.?

But there is a way out of that vicious circle: after thinning the bush, rotate your livestock across a larger number of smaller camps, thus giving the grass in those camps time to recover between grazing impacts – and beat back the bush. Farms like Buffelhoek near Otjiwarongo learnt this the hard way. Koos Briedenhann, who took over from his father Timo recently, told me they used arboricide in 1988. "We are still dealing with the repercussions 36 years later," Koos said. "It was a mistake we will never make again. Our biodiversity and palatable grasses were replaced by the invasive sickle bush" (Dichrostachys cinerea). Today, he's allocated each flerd (cattle and sheep) 8 camps - meaning the camp went from 100% grazing and 0% rest to 12% grazing and 88% rest. He is now planning to divide the camps again, into 32, meaning each camp will be grazed for only 3% of the year (sheep mostly browse the bush, cattle mostly graze the grass).

That is plenty of time for the grasses to recuperate from the grazing - and to benefit from the positive size of the animal impact, such as their fertile manure and the grass seeds being pressed into the ground by animal hooves. In that environment, the thorny bushes lose their evolutionary advantage.

The most surprising thing is how that translates into both more money - and more biodiversity. A camp can host as many as six times more animals, in the form of livestock and wildlife, than its set-stocked neighbour across the fence - and still boast way more grass, way fewer bushy shrubs, and no bare ground. A growing number of farmers now seeks to achieve a balance between trees, bush, grasses and forbs, rather than vast, monotonous stands ?of thick bush.

It’s an almost miraculously positive impact, down to one thing only: a change in the management of livestock.

But some worries remain. ?What about the carbon balance of the shift from bushland to grassland? What's probably happening is that carbon is migrating from above ground - bushes keep more of their biomass above ground than ?perennial grasses?do - to below ground, where it is pumped by perennial grasses. Finding out the truth here, obviously matters a great deal.

Others want to understand the comparative resilience of both systems. Climate models suggest that south-western Africa will become even drier than it is already, which begs the question as to whether bushland may not buffer the region against drought better than perennial grasslands would. Again, because of the better water recharge characteristics of perennial grasses, the difference is probably overblown, but it would need research.

But those are questions for another day. For now, what I'm left with is the wonder of seeing wildlife and cattle share camps that are swaying with grasses, bushes and trees - even now, at the tail end of the dry season of a harsh, multi-year drought.