Our Changing World

This week we're digging up the dirt on the surprising complexity of soil. From top-notch compost to dung beetles to kauri dieback, join us on a fascinating tour of the world beneath our feet with presenters at the Wild Dunedin Festival of Nature.

Professor Amanda Black is a big picture thinker. She likes the idea that we are just tiny dots in a vast universe. Little surprise then that her science career led her to studying soil, one of the most complex and varied ecosystems there is. 

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Amanda is the director of the Bioprotection Aotearoa Centre of Research Excellence. Formerly known as the Bio-Protection Research Centre, it was re-funded in July 2021 with a new approach in mind for how to tackle the tricky job of protecting New Zealand's productive landscapes. 

Her own research has led her from investigating how movement between landscapes affects the kauri dieback pathogen, to re-establishing land-sea connections in the hopes of increasing soil resilience to this disease. 

Based at Lincoln University, Amanda was one of the visiting speakers to the 2023 Wild Dunedin Festival of Nature. In its eighth year, the theme for this year's festival was whenua. More than 120 events across ten days celebrated the land and soils. 

As every other year, the festival began with the 7 x 7 Wild Talks event. Seven speakers are given seven minutes to talk about their chosen topic. University of Otago PhD candidate Emma Curtin used her time to talk about the insect she studies: dung beetles. These beetles are a relatively new arrival to Aotearoa, and Emma is investigating the benefits they might deliver for farmers. 

Another visiting speaker was Jim O'Gorman, known as the Dirt Doctor. Across composting workshops and talks, Jim shared his knowledge about how to create healthy, productive soils. 

Listen to the episode to hear more about Bioprotection Aotearoa, Amanda's research work, and about dung beetles and composting! 

To learn more: 

Our Changing World has extensively covered kauri dieback disease. 

Jim O'Gorman previously featured on Country Life.

The connection between seabirds and the land is something the team at Auckland War Memorial Museum is also investigating in the Noises Islands in the Hauraki Gulf. 

Go to this episode on rnz.co.nz for more details

Claire Concannon meets the latest addition to the Zealandia ecosanctuary family - toitoi, or common bully. Zealandia CEO Dr Danielle Shanahan explains why these little fish will be an important part of the freshwater ecosystem, and what their ambitious 100 year plans are to restore the mouri or lifeforce of the entire Kaiwharawhara catchment.

The native birds are loud and proud at Te Māra-a-Tāne, Zealandia. 

They flit amongst the canopy, call from the branches, preen on their perches, and even stroll across the paths. 

But today we look past the manu, and instead focus on the humble freshwater fauna living their quiet lives amongst their boisterous feathered brethren. 

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Most of Zealandia's freshwater areas are in fact manmade. The Karori upper and lower dams, completed in 1908 and 1878, were in use as drinking water reservoirs until the 1990s, when they were decommissioned due to earthquake risk. 

Now part of the fenced ecosanctuary, the team at Zealandia have taken on the task of restoring some of the native wildlife that once would have been present in this catchment. 

The Kaiwharawhara stream is born at the top of the sanctuary, collects in the dammed upper reservoir, feeds down through a man-made wetland area to the lower reservoir and then winds its way through the western suburbs and down the Ngaio Gorge, finishing its journey at Wellington Harbour beside the ferry terminal. So, an incredibly modified, urban landscape. 

To restore this valley to a hint of its former glory will take a lot of work. But CEO of Zealandia, Dr Danielle Shanahan, remains undaunted: "This is a 100-year vision of restoring the mouri or lifeforce of this absolutely incredible catchment."  This collaborative project - Kia mouriora te Kaiwharawhara, Sanctuary to sea - will involve dealing with historic landfills within the catchment, providing fish passage for native ika to be able to move upstream, and advocating to ensure future developments are freshwater friendly. 

For Danielle, it must start at home. She and the Zealandia team have been working hard to restore the upper reservoir (now called Roto Māhanga), the lower reservoir (referred to as Roto Kawau after the shags that hang out there), and the wetland area in between.  …

Go to this episode on rnz.co.nz for more details

What are the risks of head injury for players of contact sports such as rugby? Research is increasingly linking head knocks with neurodegenerative diseases later in life. Claire Concannon meets a research team analysing every rugby training session and match across an entire season with high-tech mouthguards.

Grace doesn't think about head knocks when she plays rugby: "If you see your teammates get concussed it can be scary, but when you're playing, I feel like it doesn't cross your mind, you are just more focused on the game."

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But increasingly researchers, clinicians, governing bodies, parents, and players are thinking about it. With increased research linking head knocks with neurodegenerative diseases later in life, and legal proceedings being issued by rugby union, rugby league and football players to various governing bodies, now, more than ever, people want to understand what the risks are, and how to mitigate them. 

While to date there has been a gap in knowledge about the risks at a junior level, there are a few studies currently underway in Aotearoa aimed at filling this. 

One is working with Grace's team.

Led by Professor Nick Draper at the University of Canterbury, the study aims to follow 40 junior male and female rugby players across every training and game in one full season to work out what their exposure is in terms of number of incidences, and their magnitudes. 

Nicole Spriggs, a PhD candidate at Lincoln University, is tracking the girls' teams. She does this by using mouthguards that are moulded specifically for each player using dental scans, and which contain accelerometers. They are set to measure any head acceleration event over eight G - an equivalent to your head wobbling as you bounce on a trampoline. To verify each incident Nicole also videos each training and match.

While Nicole is focused on investigating incidences in female junior players, her University of Canterbury PhD colleague Stefan Henley is focused on doing the same with under 16 boys' teams. All players also do an MRI and neurocognitive test before and after each season that Nicole and Stefan will use to investigate if there have been any changes in the structure and function of the player's brains. …

Go to this episode on rnz.co.nz for more details

Meet the winners of the 2022 Prime Minister's Science Prizes! We go behind the scenes with the Emerging Scientist, Science Teacher and Future Scientist winners to learn about cutting-edge research, inspiring teaching and intriguing mahi worthy of these prestigious awards.

It's time for the Prime Minister's Science Prizes! 

Every year, five prizes are awarded to emerging and established researchers, science communicators and educators at the top of their game. 

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The main prize, Te Puiaki Pūtaiao Matua a Te Pirimia, was awarded to the multidisciplinary National Institute for Stroke and Applied Neurosciences at Auckland University of Technology. 

Led by Professor Valery Feigin, the team has done extensive investigations into stroke incidences and burden worldwide. 

Now they are focused on developing the most cost effective, widely applicable strategies to reduce stroke incidences, including a free mobile app called Stroke Riskometer aimed at helping people lower their individual stroke risk. 

Congratulations also to Associate Professor Dianne Sika-Paotonu, who won Te Puiaki Whakapā Pūtaiao - The Prime Minister's Science Communication Prize. Based at the University of Otago, Wellington, Dianne is an immunologist and biomedical scientist. The focus of her mahi is on addressing health inequities that exist for Pacific and Māori communities, through research that is grounded in respectful and inclusive engagement with these communities.  

She was a key science communicator during the Covid-19 pandemic, and a strong proponent for Pacific and Māori researchers and health professionals to be given the opportunity to lead and make decisions for their communities. 

On this week's Our Changing World we meet the other three prize-winners and learn a bit more about their award-winning mahi. 

Te Puiaki Kaipūtaiao Maea / The Prime Minister's MacDiarmid Emerging Scientist Prize - Associate Professor Jonathan Tonkin

Dr Jonathan Tonkin began his research career sloshing through rivers in Tongariro National Park when he studied benthic invertebrates for his PhD. Today he has mostly hung up his waders.

Now, from his office in the School of Biological Sciences at Te Whare Wānanga o Waitaha, the University of Canterbury, Jonathan has a new key role: mentoring the large number of students and scientists that form his research group. Their research focus is on creating models to forecast how different communities of organisms will respond to environmental threats.  …

Go to this episode on rnz.co.nz for more details

Tropical cyclones can cause rampant destruction, but sometimes, these wild weather systems can seed life at sea too. This week we meet a storm-chasing researcher in search of phytoplankton blooms like one that formed in the wake of 2019 Cyclone Oma.

Dr Pete Russell is a storm chaser. 

But that doesn't mean he's driving new-fangled-looking machinery into the path of tornadoes or sailing ships to intercept hurricanes. 

He chases storms from his shared office in the marine science department at the University of Otago. 

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For the past seven years, Pete has been keeping tabs on tropical cyclones in the South Pacific via storm track data and satellite pictures. He is looking for a particular type of tropical cyclone - those that result in phytoplankton blooms. 

Tropical cyclones can only form over warm water that is at least 26.5℃ for the first 50m. Spurred on by some disturbance, warm moist air rises off the ocean. As it rises, it cools, and the water vapour condenses into liquid droplets that form big clouds. The rising air leaves an area of low pressure, so wind comes in from the side to fill this, which in turn warms and rises. This sets up a positive feedback loop where the cyclone continues to 'feed and grow' off the warm water it travels over. 

The winds whipped up by a tropical cyclone will disturb the temperature layering of the ocean. This means if it were to hover for long in one position, the cyclone would essentially put itself out by pulling up colder water. 

If it tracks in one direction, the disturbance at the front of the cyclone is reversed by the tail end - as the winds will blow in opposite directions. 

But if the cyclone hovers for a while, and changes direction, then it might cause a large amount of colder water to be pulled to the surface in its wake. This cooler water from further down in the ocean column contains nutrients, and when the storm passes on and sunlight hits this patch of cooler water, it can lead to large phytoplankton blooms. 

By looking at storm track data that shows the path of tropical cyclones Pete can predict whether they will result in a phytoplankton bloom. Satellite images of ocean colour, tuned to the chlorophyll A in phytoplankton, can then confirm this.

Listen to the episode to learn about one particularly large bloom event in 2019, and how these blooming cyclones might be the key to us predicting the future of tropical cyclones in a warmer South Pacific Ocean. 

The stormy Southern Ocean …

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Grab your gumboots! Alison Ballance squelches out into Nelson's mudflats with a team of Cawthron Institute researchers in search of cryptic seagrass flowers and their seeds. Collecting the seeds is step one in an ambitious project to restore Aotearoa's ailing seagrass meadows.

Nelson's Haven is an 8-kilometre expanse of mudflats. If you don gumboots and squelch your way out at low tide, you'll find it is also an expansive grassy meadow. 

The grass is seagrass, the only flowering plant that lives in the sea. It provides key habitat for many fish species, as well as performing a vital ecological role cleaning water, stabilising mud and sequestering carbon.

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Marine ecologists from the Cawthron Institute have just completed the first summer of a three-year research project to develop new ways of restoring seagrass meadows - using seeds. 

Until recently, it was thought that seagrass in New Zealand, which belongs to the species Zostera muelleri, only rarely flowered and set seed. But the marine restoration team at the Cawthron Institute have discovered there are actually plenty of flowers, although team leader Dr Dana Clark admits the greenish flowers are cryptic and hard to find.

The Haven is one of three study sites near Nelson, along with Waimea and Delaware / Wakapuaka estuaries, for the project Restoring Aotearoa New Zealand's Seagrass Meadows. Over the past summer, the seagrass team has been surveying its field sites and monitoring flowering. The researchers have discovered that flowering begins in October and ends in February, with peak flowering in December.

Dana says the team collected about 3000 seagrass flowers, which were taken back to the lab. Here they were kept in two tanks of bubbling water which marine ecologist Dr Anna Berthelsen describes as a 'seagrass spa.' The bubbles keep the seagrass well oxygenated as they mature, allowing them to develop naturally and shed pollen into the water which fertilises female flowers that go on to develop seeds.

Dana says they were thrilled to collect nearly 600 seeds, which are being stored ready for germination trials. Armed with this summer's findings, she hopes the project will produce even more seeds next summer. …

Go to this episode on rnz.co.nz for more details

The birds are back. After a long absence, 11 kiwi have returned to the outskirts of Wellington with a little help from some human friends. Veronika Meduna heads into the field to see how the work of the Capital Kiwi Project is paying off.

Imagine taking an evening walk around the fringes of the capital city and hearing the call of the kiwi.

Well, you no longer need to imagine. 

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This vision of kiwi once again roaming the windswept hills on the outskirts of Wellington is becoming reality with the arrival of 11 North Island brown kiwi, set free in the scrubby landscapes around Mākara late last year.

This flock is just the beginning. The ambitious Capital Kiwi project plans to bring back 250 kiwi over the next six years to re-establish a thriving population on 23,000 hectares of land that stretches from the Red Rocks on Wellington's south coast all the way to Porirua. The first pioneers are a gift from the Ōtorohanga Kiwi House and Ngāti Hinewai to the local community and Taranaki Whānui. 

The Mākara community have put in years of hard work (and more than 4500 traps) to clear introduced predators and make the area as safe as possible for the new residents.

"In unmanaged sites, 95% of chicks are eaten by stoats. To grow a kiwi population, you have to have one in five chicks survive, but we're aiming to do much better than that," says project founder and leader Paul Stanley Ward. "What we'd like to have is a self-sustaining, wild, free-ranging population of kiwi where they can live as they have done for millions of years in these hills."

"Fundamentally, if our relationship with a bird like the kiwi ends up being behind a fence or in a zoo, we'll lose our aroha to care for them. But we know we can recover kiwi populations - and for us, it's about doing that in the backyard of our capital city."

Thank you to Dave Allen for providing photos for this story. www.daveallen.photography

To learn more:

Watch this short piece about the second release of kiwi from Sanctuary Mountain Maungatautari

The tracking of this first release was also featured in Summer Time in January 2023

Visit the Capital Kiwi Project website.

In 2018, Alison Ballance reported on the rise of native birds in Wellington.

Go to this episode on rnz.co.nz for more details

The Rotopiko peat wetlands are a haven for rare and threatened wildlife. But when a flock of introduced birds numbering in the hundreds of thousands moves in - threatening the very nature of this special place - a group of people come up with some crazy-but-genius ideas to protect the wetlands and wildlife. Claire Concannon investigates.

Half an hour south of Kirikiriroa Hamilton, the Rotopiko wetland reserve is an oasis of trees in a desert of farmland.

At dusk, these trees fill with hundreds of thousands of starlings and sparrows, jostling for position on the branches, like noisy restless shadows. 

It's an incredible spectacle... but these birds are not welcome here. 

Listen to the story

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"These birds are bringing in massive amounts of nutrients," says Karen Denyer, the executive officer of the National Wetland Trust of New Zealand.

"'We are trying to restore this wonderful site... and we've got this unintentional and kind of unexpected problem."

Rotopiko is a peat lake wetland complex. An ecosystem naturally low in nutrients, to which some rare native New Zealand species are perfectly adapted. For example, the endemic giant cane rush, and the caterpillar that lives inside it. They were translocated into the sanctuary years ago, as the group set about restoring the area. 

It's been a lot of work - a massive weeding effort, erecting a predator-proof fence, removing predators, building paths and a boardwalk, creating an information trail, replanting kahikatea trees. 

But now it's at risk. 

Just two years after the predator-proof fence was put up, and the predators removed, birds started to come to roost at night inside the ten-hectare fenced area in large numbers. The nutrients in their droppings threaten to change the very nature of the wetland. 

Because there are so many birds it's a major challenge to count them. Researchers from Toi Ohomai Te Pūkenga and Wintec Te Pūkenga have come on board to help. They have developed different methods to estimate changes in the number of birds, so the Wetland Trust can test the effectiveness of different deterrents. 

Laser lights, noise, shooting, a product like pepper spray for birds, wood vinegar - nothing has worked so far. This has forced the Wetland Trust into trying a less desirable and more controversial method - returning rats to a rat-free area.   …

Go to this episode on rnz.co.nz for more details

As mountains get warmer with our changing climate, what will happen to the iconic alpine plants that live at high altitude? Claire Concannon visits the moonscape slopes of Mt Ruapehu with a team of researchers using an experimental set-up that's part-greenhouse, part-UFO.

It looks like the work of a small alien race. On the moonscape slopes of Mount Ruapehu, hexagon shapes enclose small patches of scrubby plants. 

But these are not UFOs. These contraptions are more like time travel machines. 

Listen to Our Changing World

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This alpine habitat plays host to a climate change experiment, investigating what will happen to plants here in a warming world. The hexagonal perspex chambers heat the soil and air temperature by 2°C - the predicted average rise in temperature in alpine regions up to 2070. 

The site is one of just 20 worldwide that form the WaRM network - Warming and Removal in Mountains. Dr Julie Deslippe of Te Herenga Waka, Victoria University of Wellington, leads the research at these sites in Tongariro National Park.

The New Zealand team regularly monitor the plots to answer questions about what will happen to the biodiversity and carbon flux of these ecosystems as they heat up. Which plants are winners? Which are losers? Will heating mean the plants grow bigger, photosynthesise more, and take up more carbon? Or will the warming stress the plants out, meaning they respire or 'breathe out' more carbon? 

Around the world there are ten countries with ten mountains participating in the WaRM network. Each has both a high- and low-elevation site on the same mountain, separated by at least 500m of altitude. The experiments are set up and monitored the same way in each location. Records are taken of the soil and air temperature, the plant species, percentage coverage and biomass, and the carbon exchange happening between the plants, soil and the atmosphere.

In some 'removal' plots, the most prevalent plant in the area has been taken out to see how this impacts plant biodiversity. At the low-elevation site in New Zealand, this dominant plant is invasive heather, so these plots give a window into what the future might be like if ongoing heather control methods prove successful. The research has been underway for eight years now, and with all this data, the team are starting to figure some things out. 

Listen to the episode to find out what they have learned about the future of our alpine plants. 

To learn more:  …

Go to this episode on rnz.co.nz for more details