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Writer's pictureNatalie Jessup

Bringing Biodiversity Home

With Gardenstar nearing the end of its first phase of development by the Endangered Species Foundation and the Ministry for the Environment, Gardenstar Project Manager Bex De Prospo sat down with Co-Founders Yolanda van Heezik and Philip Seddon to learn more about the concept behind the metric tool and their inspiration to bring biodiversity home.



“Yolanda leads us and I mostly say ‘that’s really good’ and make encouraging noises,” jokes Philip. Yolanda laughs, “I’d say it’s just a little more complex than that.”

The Co-Founders met as PhD students at the University of Otago in the 1980s and have been partners in science, and in life, in the decades since.


“We were both doing PhDs on the yellow-eyed penguin; afterwards we went together to the University of Cape Town to do a shared post-doc on the behavioural ecology of African penguins,” Yolanda says. “When we finished studying, we looked at a range of job opportunities and both applied for the same job in Saudi Arabia at the National Wildlife Research Centre. My application was rejected because they weren’t accepting women at that time, but Phil’s was successful.”

They got married and relocated to Saudi Arabia, where Yolanda eventually convinced the Centre to employ her as a ‘proper scientist’ and the two studied near-extinct populations of the iconic Arabian Oryx and Houbara Bustard. This work refocused their energy from behavioural ecology into conservation, a space they have continued to occupy throughout their careers.



In 2001, the couple found themselves back at the University of Otago sharing one teaching and research role in the Zoology Department which has grown into two overlapping roles over the last 20 years.



“The main theme of my current work,” Philip says, “is restoration of critically endangered species. In particular, using the tool of conservation translocation: moving them from one place and releasing them somewhere else to try and establish a new population. I also work with students on pest species and how we can better manage pests, including in urban landscapes.”

This ties in with the work that Yolanda is doing in urban ecology, a space which she says allows her to explore the sociological and human perspectives around conservation, and to look at Aotearoa’s gardens in a holistic way.


“I see so much scope for improving biodiversity across our cities and the potential knock-on effects for human well-being. I’m also aware that this creates impact in other ways: if people appreciate their natural environments, they’re much more likely to vote for ‘green’ candidates and do tangible things to promote the environment in their local area.”

Their decades of shared interest and collaboration culminated last year with a brand new initiative called Gardenstar, a metric tool which provides a robust, scientific framework with which to assess the biodiversity of any garden in Aotearoa. While speaking on behalf of the MBIE-funded research programme, People, Cities and Nature at a pre-COVID Urban Futures conference in early 2020, Yolanda met a manager from Kāinga Ora and learned about the lack of guidelines for what happened to the land surrounding the major building projects they are undertaking throughout Aotearoa.


“We talked about the Homestar accreditation programme about how that could be modelled and applied to gardens. I brought that thought back to Phil, who was then a trustee for the Endangered Species Foundation. We had collaborated previously on a couple of research projects where our interests had overlapped. We worked together a lot at the beginning of our career and found that we were really synergistic when we worked together, so I welcomed the opportunity to do more.”

“That conversation sparked an idea for me,” Philip says, “because I knew that Endangered Species Foundation had been funding piecemeal projects but what they were really looking for was something that they could own for themselves. It seemed to me that you could bundle a whole lot of things up under the idea of a garden accreditation for biodiversity. It also created the opportunity to shift some of the focus from big, charismatic species to the smaller things that we can all look after."

People are most of the solution and most of the problem, so you’ve got to engage with them where they live. Many people seldom or can’t access our National Parks and backcountry areas. So if you signal that biodiversity is something that exists only in the more remote areas, then the danger is that biodiversity becomes external, somewhere else, and unimportant to daily lives. But biodiversity is all around us. Our gardens can become our own National Parks.”

Yolanda with black stilt chick


With enthusiastic support from the Endangered Species Foundation, the Co-Founders got to work assembling a technical advisory group to define exactly what they wanted Gardenstar to measure.


“There were some intensive sessions when we started creating the ratings,” says Yolanda. “We used conjoint analysis [a research approach which quantifies preferences to determine the relative importance of different features/options] to assess which aspects of biodiversity we should measure.”

After months of refinement, the result is a powerful scientific tool which provides a biodiversity rating which can then be converted into a more digestible star system for end-users.


In April of 2021, the concept was co-funded for future development by the Endangered Species Foundation and the Ministry for the Environment. Using the metric tool as a strong foundation, the future of the Gardenstar concept is now being co-created through an in-depth community engagement process to learn about the biodiversity needs, aspirations and barriers of Aotearoa’s urban residents.


Through a series of targeted interviews, workshops and pilots, potential users are providing deep insights into how the science behind Gardenstar could be adapted and applied in a tangible way to enable Aotearoa's residents to improve biodiversity in their own communities and create maximum impact for our native species.


In practical terms, Yolanda and Philip say that there are a number of things that we can all do to improve our biodiversity impact today.


“Plant native species that are taller than knee height,” says Yolanda. “They don’t need to be huge trees, but try to add a bit of vertical diversity and complexity. Also, put some measures in place to control your cats. If you already have indoor-outdoor cats, get them a brightly coloured collar and keep them indoors at night. Investigate building them a contained ‘catio’ to allow them outside without roaming. And if you’re getting a new cat, consider making it exclusively an indoor cat.”

We should also limit our lawn space, Philip says. “We grow lawn for weird reasons, some of which stem from British colonial-era holdovers that say you need a manicured, monoculture green space. Allow things to get messy: rotting wood and unkept garden space support all kinds of invertebrates which, in turn, support additional species.”


On their own property, the Co-Founders have devoted the whole front garden to native species which they have allowed to grow mostly wild, as well as installing some predator traps. The rear garden features some home sustainability projects: a compost heap, a productive food garden and some potted flowers for colour.


“Not all of these things directly will improve your biodiversity,” says Yolanda, “but there’s always a bit of a compromise. There’s no reason why you shouldn’t grow food and flowers, even if they aren’t native. It’s the gardens with virtually no natives where we see massive room for improvement.”

Looking ahead, Philip is renewing some of his old connections with Saudi Arabia to explore protected area creation for endangered species. Both Philip and Yolanda are working with students on landscape-scale mammalian pest control, a space that they say is of particular interest as Aotearoa looks ahead to a Predator Free 2050.





Yolanda is exploring childhood experience with green space and how this impacts biodiversity preferences in adulthood, as well as exploring the concept of a VR intervention which would allow those with limited mobility to experience interaction with nature in the virtual world.


Both eagerly await the results of the Gardenstar pilot in July of 2021, with the hope that this development trial will yield a sustainable model for Gardenstar to grow and scale.


“My dream outcome for Gardenstar is widespread national recognition, not just by individuals but also by organisations like Kāinga Ora. That would be a fantastic outcome,” Yolanda says.
Phil agrees. “I’ve kept a very open mind; I don’t have a lot of expectations for what Gardenstar will ultimately end up becoming because it probably won’t end up being whatever I think it is. I just hope that something comes of it that makes a real difference.”



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