Our Changing World

Measuring the value of a community garden and the challenges of growing dune plants for restoring sand dune communities.

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Summer students from Victoria University of Wellington have been helping the Innermost community gardens in Wellington put numbers on their social and environmental values.

Research shows that community gardens provide more than just silverbeet and beans - they promote a sense of engagement and belonging in a community.

And it turns out that a good composting scheme will also attract people from the surrounding suburbs who are keen to recycle their food scraps.

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Wellington's Innermost Gardens is a large, successful community garden located next to the town belt on Mount Victoria.

It was created on the site of an old bowling green and marching lawn, using permaculture principles and raised beds.

Innermost Gardens runs regular working bees and is supported by a large number of volunteers coordinated by a core group.

It has been the subject of a recent Victoria University of Wellington summer student research project, which has helped quantify its social and environmental benefits.

Core group member Chris Montgomery says they requested the research because "we know that we're doing better for this land than if it was a marching lawn, but how do you put a dollar value on that?"

" know that we're here," says Chris, "yet on their balance sheet we're just a certain amount of income from renting the hall."

"We wanted to be able to say that while you may see us as a one line item on your balance sheet, actually we bring a whole lot more benefit to the community by just being here and doing what we do."

Architect Fabricio Chicca, from Victoria University of Wellington's Faculty of Architecture and Design Innovation, has a long-standing interest in urban agriculture and community gardens and he has supervised the summer research.

The first project, he says was carried out a few years ago for Wellington City Council. The council were interested in knowing how many community gardens there were in the city and how successful and productive they were.

The survey identified 21 gardens, which varied greatly in size and effectiveness.

Fabricio says that the greatest benefits offered by community gardens are social ones, rather than sustainable environmental ones.

Community gardens are, he says, not the most productive use of land but are appreciated for other reasons.

The most recent Victoria University of Wellington summer student was Bliss Graetz, a landscape architecture student…

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Each year Jo Bonner and the team at Coastlands Plant Nursery in Whakatane grow 300,000 spinifex and pingao plants for dune replanting at beaches around the North Island.

New Zealand's iconic native sand dune plants, pingao and spinifex, are getting a helping hand from a dedicated horticulturalist.

Jo Bonner is so committed that she has been known to chase down the beach on a windy day in pursuit of the best - and fastest - rolling spinifex seed heads.

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Each year, horticulturist Jo Bonner and the team at Coastlands Plants in Whakatāne grow 200,000 spinifex plants and 100,000 pingao plants.

They're the largest supplier of these in the country and their plants are used by councils and coast care groups in dune revegetation programmes around the North Island.

"The most important thing about the foredune plants is their ability to fix the dunes after a large storm event," says Jo.

The key, in the case of spinifex, is long vigorous runners which grow towards the sea and quickly cover foredunes ravaged by storm swells. The hairy plants then trap wind-blown sand which rebuilds a gentle dune.

"Both spinifex and pingao are our fall guys - they're the ones that take the brunt of the storms."

Jo says that widespread introduced marram grass, planted in the past to provide food for stock being driven along the beaches, doesn't bind sand dunes during a storm; it simply washes away, making it much less effective than the two native species at protecting the coast.

But while both native sand binders, spinifex and pingao, do a great job in holding and rebuilding sand dunes, life in modern-day New Zealand is not easy for them.

Jo says that pingao was once widespread but has slowly disappeared in many parts of the country. It is eaten by rabbits, and its seeds are eaten by rodents and introduced birds.

Jo reports seeing big flocks of sparrows feeding in front of her team when they are out collecting seeds at various beaches, and sparrows are also a big problem at the nursery.

Coastlands Plants has been in the nursery business for many years.

The revegetation process begins with seed collection, and Jo says it is important to collect seed that is local to each beach.

Nursery staff collect in the Whakatāne area, while local coast care groups collect in their own areas.

Peak seed production coincides with Christmas and busy holiday times at local beaches and Jo says that sometimes just finding a car park can be a challenge…

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University of Otago student Jenny Stein is finding out how rising sea levels are a growing problem for many coastal settlements, including the densely populated suburb of South Dunedin.

University of Otago science communication student Jenny Stein is finding out how rising sea levels are a growing problem for many coastal settlements, including the densely populated suburb of South Dunedin.

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When University of Otago student Asia King got the call to take part in a study using ketamine to treat depression, she said yes - and made a podcast about the experience.

When University of Otago science communication student Asia King got the call to take part in a study using ketamine to treat depression, she said 'yes' - and made a podcast about the experience.

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University of Otago student Ruby Parker says it's important to talk about abortion. She is in conversation with researcher Emma Harcourt.

University of Otago science communication student Ruby Parker says it's important to talk about abortion. She is in conversation with researcher Emma Harcourt, following the passing of the 2020 Abortion Legislation Act.

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Epiphytes are the high rise experts of the plant world, and resilient buildings should save lives and still be useable after an earthquake.

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Low-damage buildings don't just save lives in an earthquake - they are designed to be resilient so they can stay in use.

Low-damage buildings don't just save lives in an earthquake - they are designed to be resilient so they can stay in use.

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Geoff Rodgers is an earthquake engineer with the University of Canterbury and QuakeCoRE. He is working to create low-damage buildings that will not only save lives in an earthquake but remain functional.

He talks with Alison Ballance about various ways to build low-damage buildings and about using a giant shake table in China to subject a full-size building to the kind of shaking experienced in real-life earthquakes.

Example of a low damage building

Christchurch's new library Tūranga includes extrusion dampers. Geoff says that these are strategically bolted between key base walls and the foundation to act as motion restraints in the event of a large earthquake.

Each seismic damper is a metre long and weighs 185 kilograms.

"Under a low level of shaking, this building will respond just like a fixed base structure. Once you get beyond that low level of shaking, it has been designed to roll and move at the base but in a controlled way," he says.

Lessons from a shaky decade

A decade of earthquakes - Darfield. Christchurch. Cook Strait. Kaikōura. In the past decade, New Zealand has experienced four major earthquakes. Three GNS Science seismologists recollect their experience of the Big Ones and talk about the lessons we have learned from these ten shaky years.

Preparing for the next big quake - University of Canterbury earthquake engineer Brendon Bradley says we can't predict when and where earthquakes will occur, but "we do have probabilistic models that tell us the likelihood that certain faults are going to rupture over a certain period of time."

Designing low damage buildings - Low-damage buildings don't just save lives in an earthquake, says Geoff Rodgers - they are designed to be resilient so they can stay in use.

What we do during an earthquake and why it matters - David Johnston says say that when it comes to earthquakes, sometimes doing nothing is a safer option than taking the wrong action.

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Discover the hidden world of arboreal plants, which get a leg-up in the world by living on trees.

Discover the hidden world of arboreal plants, which get a leg-up in the world by living in the trees.

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Victoria University of Wellington PhD student Tom Dawes says ten percent of the world's plants have forsaken the ground to live in the tree tops, a place that fellow ecologist K.C. Burns describes as a 'hidden world.'

Life in a forest is a race to the top, to get as much sunlight as possible - and by starting life in a tree, epiphytes are getting an advantage over their competitors.

Epiphytes have various strategies for life at a height.

Some arrive as seeds or spores blown on the wind, while others are deposited by obliging birds dropping seeds in their, well, droppings.

Some such as leathery-leaved climbing ferns scramble over tree trunks in the mid canopy, neither touching the ground or reaching the sun. The make do with whatever nutrients the rain washes in.

Other species, such as New Zealand's mostly flame-red mistletoes, are semi-parasites. They tap into their host's branches to steal food and water, but prefer to perch in the very canopy of the tree to claim a share of the sunlight that they also use for photosynthesis.

Some species such as puka, Griselinia lucida, are equally at home on the forest floor or in the crook of some high branches. From there, they send down long roots that grow into the soil.

Other species begin on the ground and then scramble skywards.

Astelias, or nest epiphytes, create their own miniature world, trapping water and rotting humus to feed themselves.

Tom and K.C. recommend looking up next time you're walking in the bush - you might be surprised with how many epiphyte species you find.

They recommend Otari Wilton's gardens in Wellington as a great epiphyte-viewing place.

Mistletoe rescue mission

Hear about a pioneering attempt to translocate mistletoe into Zealandia sanctuary.

Listen to the full podcast to hear plenty of interesting anecdotes about epiphyte lifestyles.

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An earthquake engineer talks about modelling strong ground motions in an earthquake and a psychologists talks about what it takes to have a good life.

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