Gorse strategy 1: use it for good
IF YOU forced me to choose between fire and flood, I’d take fire – at least there’s a fighting chance.
We’ve faced both. In March 2020, an errant spark from a neighbour’s chainsaw ignited a pile of sawdust, then spread into the gorse on our block and those around us, driven by high winds.
But back in 2014, just after moving here, we learned the greatest risk we face is landslips in the steep gully above Purua Stream. You can still see the slips we experienced during 2015 and scarring along the slopes from previous heavy rain events.
One of those scars has three huge poplars growing in it. Most of the others are covered in gorse.
The best way to hold hillsides like ours in place is to let gorse do its job as a pioneer species, holding and building soil.
Under normal conditions, ecological succession takes decades, but we’re able to speed up the process with an approach I call ‘managed succession.’ Like many pioneer species, gorse is shade intolerant and won’t grow or germinate underneath a canopy of its own or other trees and shrubs.
Conversely, many native trees characteristic of climax forests are shade tolerant when young, and can grow up through a low canopy of pioneers, eventually shading them out.
We’ve been able to speed things up by planting 3m poplar poles into some of the dense stands of gorse – protected by plastic sleeves where we run the goats – and good-sized native seedlings where we don’t run the goats.
This method means:
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we immediately take a decade off the clock, jump-starting the secondary growth versus waiting for seeds to germinate in the gorse litter;
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we’re able to retain the soil holding and soil building characteristics of gorse on our most vulnerable slopes.