A note to my Yarns from the Farm Readers—this is the fourth instalment of a series on biodiversity for our local newspaper. Biodiversity was the introduction, the second was Biodiversity and Nutrition, and the third was Biodiversity and Weeds Nan
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If you can’t say somethin’ nice, don’t say nothin’ at all.
—Thumper from ‘Bambi’
Surprisingly, there are several nice things I can say about gorse, despite its notorious dominance in the woody weed stakes for Tasmania.
Gorse is (you guessed it) extremely nutritious, with high protein levels, comparable to other legumes like lucerne. In the 1800s, when horsepower really meant work by animals with four legs, gorse chaff was the primary winter feed for the working horses of Great Britain. In fact, land where gorse was cultivated was taxed at a higher rate, as it was considered such a valuable asset.
Gorse is also good habitat for native animals, including wallabies and devils, and it provides a natural “nursery” to protect native tree seedlings from browsing by livestock.
And that’s about it for the somethin’ nice.
Gorse in Tasmania is able to set seed twice a year, unlike in the harsher British climate. Gorse here has no serious woody competitors among the native or introduced species. Nor do we use it for chaff, which would provide some level of control. As a result, gorse has simply taken over large swathes of our landscape, especially areas that are difficult to plow.
Almost everything we farmers are told to do to eradicate gorse simply makes the world safer for gorse to grow. Gorse needs sunlight to germinate and grow—it can’t even germinate in its own shade. So when we use herbicides or mechanical means to clear gorse, we’re throwing it in that briar patch—creating just the conditions it needs to rejuvenate. Gorse seeds are long-lived in the soil and are activated by fire, so burning gorse also just encourages it to propagate.
I’ve spent a good part of my 20 years farming trying to tame gorse. After years of bulldozing, burning and spraying, I realised that resistance, at least the way I was doing it, is futile. Inspired by the Hinewai project on the south island of New Zealand, near Akaroa, I decided to change tacks altogether.
More than 30 years ago botanist Hugh Wilson and philanthropist Maurice White bought 1000 ha of steep, gorse-dominated farmland, to experiment with using botanical succession—the natural sequence of plants out-competing other plants—to control gorse. The land they purchased comprised about ¾ gorse and ¼ native forest.
Over the intervening decades, they worked hard to eliminate non-native browsers and to limit bushfires in the reserve. It is now ¾ native forest, and ¼ gorse. They did not use any herbicides, nor did they manually plant any trees. They simply made it possible for nature to follow its natural course.
Because gorse can’t grow or germinate in shade, allowing heavy shade trees like she-oaks or blackwoods to grow up through the gorse eventually provides a shade canopy that ultimately destroys the gorse. She-oaks have the additional advantage of allelopathy—the ability of a plant to chemically inhibit germination of other plants within its sphere of influence.
Botanical succession won’t get you gorse-free pastures, but it will create a gorse-limited native forest, and doesn’t require the use of herbicides, both advantages in the biodiversity context. It will also take decades to make the transition.
Hinewai’s success inspired me to try the same thing on my 100 acres of dense gorse, in which I have islands of mature she-oaks, blackwoods and eucalypts. Although I probably won’t live to see the full transition, the forest of she-oak seedlings sprouting up through my gorse patches (see banner photo) are harbingers of a biodiverse future for what has been an impenetrable thicket ever since I started farming.