On the day that the World Meteorological Organisation reports that 2024 was likely the first calendar year to average more than 1.5 degrees Celsius above the pre-industrial era, the answers to addressing climate change are still simple and staring us in the face: cut our use of fossil fuels, grow food locally and with minimal imported ingredients, and – in many places – restore natural, complex, balanced ecosystems. I don’t like the term ‘nature-based solutions’ – nature IS the solution.
On the past weekend, I was fortunate – and disturbed – to witness two contrasting ‘ecosystems’ play out side-by-side. I was on the Hauraki Plains on Sunday, not at the summit this time, but at ‘Ground Zero’: on the boundary between a vast, unassuming ecosystem and our modern over-the-top industrialised agriculture. Just off State Highway 26, with cars speeding along at 100 km/hr between Morrinsville and Auckland, a short gravelled road diverted me to a stream skirting round New Zealand’s largest remaining unaltered raised peat bog. Kopuatai Peat Dome is 10,201 hectares in area, lies between the Piako and Waihou Rivers 70 km northeast of Hamilton, and is rising by about a millimetre a year.
Through a sign-posted gate reading ‘please close the gate’, I went to the end of the road, parked the car, then on foot skirted around the stream, watching and taking photos of what looked like low-growing scrub with a few small kahikatea growing out. It was a tranquil time, almost sacred, as I watched debris drift silently down the stream.
Later, I read how this peat bog has been slowly, silently, and effortlessly absorbing CO2 for thousands of years; its lowlying ecosystem sustaining a huge variety of low-life plants and insects. According to the Department of Conservation, it is also home to 54 species of birds (27 protected, 17 unprotected and 10 game birds), and important fish species such as the black mudfish and the endemic long finned eels.
A 2022 article in the Forest & Bird magazine explores the value of the peat dome largely through the eyes of Waikato University wetland expert Dr Dave Campbell.Peat bogs form in low-nutrient, water-logged areas where dead vegetation only partially breaks down due to an absence of oxygen and microbes. Semi-decomposed plant matter accumulates slowly but steadily – and is exceedingly rich in carbon. Such that Kopuatai holds 2400 tonnes of carbon per hectare, compared to a mature pine forest’s 300 tonnes. However, a pine forest is destined to be cut and milled, releasing CO2 again. Kopuatai has been accumulating carbon over thousands of years, and will continue to do so, undisturbed, in “a constant state of slow but steady carbon uptake”.
Even natural forests, when they reach an old-growth stage, will either burn (releasing carbon) or their uptake of carbon will simply level out.
The article notes that 75% of Waikato’s wetland areas – and 90% of wetlands across Aotearoa – have been drained and converted to farmland, introducing oxygen back into the soil, and turning these highly efficient carbon sinks back into major carbon sources. Dave’s research indicates that a single hectare of drained peatland will emit up to 30 tonnes of CO2 per year.
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Meanwhile back on the ranch …. my tranquil Sunday
observations of the peat dome were about to be disturbed as I heard distant
murmurings of machinery. Down the farm track I’d just walked along, came the convoy:
a mammoth combine harvester followed by four wagon-pulling tractors, to gather
up the cuttings from the harvester as it chewed up a field of maize. It
reminded me of Philip Reeve’s “Mortal Engines” book series, where huge mobile
cities crawl around gobbling up smaller towns – including their human populations
– to provide resources and labour for ongoing growth. The books are a metaphor
for our globalised capitalist system of gobbling up resources, to benefit the
wealthy and comfortable.
I don’t know how much energy and resources from ‘elsewhere’
was poured into this five vehicles, nor how many external inputs went into the
maize field; nor how many cows – or stock units – would be fed by the maize
sileage produced, nor how much of that milk (or meat) will be consumed locally,
and how much exported. There may be a positive credit in the farmers’ and
industrialists’ bank books, but there will be no carbon credits for the Earth,
only deficits. Making cents in someone’s economic analysis, but not much
‘sense’ ecologically.
But wait – there’s more! Resilience to drought
Dave Campbell’s research has also shown the remarkable resilience of the bog to drought. By rights, the bog shouldn’t even be here in such a relatively warm place as the Hauraki plains. From the F&B article:
“Northland and Waikato are the antithesis of the parts of the world where you’d expect to accumulate deep peatlands, because this is a warm, seasonally dry climate,” says Dave. “They simply should not exist.”
The plants hold the key.
“Wetland plants like Empodisma robustum – jointed wire rush – have particular adaptations that enable them to hold onto the water they get from rainfall. This indicates they are equipped to withstand the effect of seasonal droughts.
“The big lesson we’ve learned is how resilient these particular peatlands are to a fluctuating climate. That is globally unique, and it gives us hope that they’ll be very resilient to climate change.”
Wetlands such as Kopuatai also act as filters to provide clean, fresh water. Dave advocates wetland restoration for its multiple benefits: “It’s about water quality, biodiversity, and it’s a major carbon sink that is perhaps more resilient than standard pine forests.”
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More photos from the peat dome below – and nearby Morrinsville. “Power farming” and the modern equivalent of the ‘golden calf’? Very fitting, I felt.