'Helihackers' swoop in to protect Table Mountain's fynbos and fresh water

They came: by helicopter, armed with chainsaws. They saw: invasive alien trees on Table Mountain. And like Caesar’s army, the hackers conquered: cutting down more than 2,000 pines in two operations.

Eighteen volunteer “helihackers” removed more than 1,300 pines and other invasive trees from the mountain’s upper slopes, and 800 invasives from its lower slopes, over just five days in October.

Helihackers are skilled mountaineers and tree surgeons who — strapped together in threes beneath a helicopter and flown to inaccessible mountain slopes — risk their lives to eliminate invasive alien trees.

Veteran helihacker and mountaineer Douw Steyn said: “We felled trees in a wide area between Newlands Ravine and Kirstenbosch. Table Mountain is the only area where we have worked which has a lot of people using it. We had to close hiking trails for the safety of the public when we were working.

“This, combined with fickle weather, especially the southeaster which forced us to select suitable days at short notice, complicated the planning and logistics. But we didn’t have to worry about the logistics of camping up in the mountains because these were single-day operations close to home.”

The only female veteran helihacker, Dr Kate Larmuth, said it was more difficult to work on the slopes above Newlands than they had expected because the ground was steep, loose, wet and slippery.

“We saw large pine carcasses still there from the late 80s and early 90s, when the famed ‘A-Team’ were trained to clear the pines on the cliffs. If they hadn't done so, our task would have been even monumental. Some of the larger trees we felled off the cliff edges were ringbarked around the same time but survived,” she said.  

When the wind was too strong for the helicopter to fly on the first weekend, the hackers relied on their fitness and climbing skills to get to dangerous slopes on the eastern side of the mountain.

The team worked with multiple partners on Table Mountain to remove the invasives, including The Sugarbird Trust, which works with SANParks approval.

Invasive aliens threaten indigenous vegetation, like the Cape’s unique floral kingdom, and fuel damaging wildfires.

“The alien plants also use a lot of water,” said Dr Glen Moncrieff from the South African Environmental Monitoring Network. “If the pine trees were allowed to spread, they would colonise the area at a rapid rate and greatly reduce the amount of runoff. By 2050, 30%-40% of the water could be lost from our catchments.”

The helihackers are a tireless crew who spent the past weekend, November 8-9, on another operation in Greyton, in partnership with the organisation Wild Restoration Greyton.

More than 12,000ha have been cleared in 21 operations in areas including Greyton, Tsitsikamma, Milner Peak, Hex River and the Limietberg mountains since the helihacks started in 2017, said founder and arborist Aleck McKirdy.

Dr Guy Preston, a conservationist and retired deputy director-general of environmental affairs, said: “This work is extraordinarily important. It is difficult, dangerous and expensive for the (official) 'high-altitude teams' to clear the invasive plants on our cliff-faces.

“The helihack team reach the trees that are most critical to clear, that otherwise rain down seeds, perpetuating the problem of invasives. It’s not just the big trees that are cleared but every invasive tree, from seedlings to the giants.

“Their work is invaluable.”

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