15 minute read

A biologist who became infected with a passion for plants

A lot of the research in which Emma is involved is translated into practical advice for home gardeners. I recently caught up with Emma to find out more about herself and the research projects she oversees at Auckland Botanic Gardens.

Have you always been interested in plants? How did your career path lead you to the Auckland Botanic Gardens?

I’ve always been interested in nature. I was one of those kids who went to the zoo with a clipboard and drew what I saw. I studied biology at university and just naturally fell into conservation-related projects. I did a master degree on native orchids and their pollination.My current job is the first job I got when I left uni and I’m still here seven-and-a-half years later. I guess I landed my dream job!

What is your current job and what drives you?

I started my role as Botanical Records & Conservation Officer when I started at the gardens.I manage our plant records database, creating accessions, updating records and verifyingnames. I also make the tags and labels that our visitors see in the garden. I oversee allresearch at the gardens, which includes planning plant trials, data analysis and report writing,facilitating external researchers to use the gardens or the plant material in our collection andworking with external scientists on research projects that align with our goals. I also carry outany conservation projects, both native and non-native. This could be anything from collecting material in the wild, seed collecting from our seed orchards, working with community groups on threatened plant projects, and advocating for the plight of threatened plants through education of visitors and students.

We’re quite a small garden with only 30 staff or so, and I’m the only one with a science role. I get my passion and drive from the people I work with. The community of botanic gardens is pretty infectious! I’ve always had a love for nature but learning from other people really fuelled my interest in plants – people like my previous boss Bec Stanley, who is a native plant person in New Zealand, and some of my Australian colleagues like Greg Bourke.

You were recently nominated as the convenor of BCARM. Why did you take on this role and what does it involve?

I help facilitate meetings and workshops on topicsinvolving plant collections and records. I joined thegroup because I’ve had a lot of experience with plantdatabases. I travelled to the USA in 2016 to visit otherbotanic gardens and to learn how they work with theirplant records. I wanted to share my experiences and offer support to other BGANZ members. I loveworking with the group of passionate people in BCARM. It’s one of the most rewarding parts of myjob. I’ve been involved in the Regional Database Project which has used my knowledge and skills,and I’ve met lots of new botanic gardens staff that I like to think of as my colleagues. They are oftenpeople I brainstorm with or ask for advice. It’s really useful to gain a different perspective, fromoutside my own garden.

Our theme for this issue is ‘plant science − research in botanic gardens’ – what role do you think botanic gardens have in this area? What type of research are you involved in?

There’s so much that we can be involved with in terms of climate change, in futureproofing whatpeople are growing. For example, in the gardens our motto is ‘where ideas grow’. Everything thatwe grow in our collection are plants that we’ve recommended to the public that would do well inAuckland. Those plants go through a trial system to test that they would survive our conditions.We do that through a formal trial process for anywhere between three and five years, we collect thedata and then write it into a report that we publish, and then those plants from the trial that ratewell in our rating system go into the main collections. We also get advice from local experts thathave been growing these plants for a long time, sometimes 30 years. Considering climate change inthese recommendations is really interesting − we need to be aware that the plants we’re currentlyrecommending must remain suitable over the next 20, 30 or 40 years. As we don’t have theexpertise here, we use the BGANZ network to talk to people like Peter Symes at RBGV Melbourne.

They’ve got some climate-based models that we can draw on to see if there’s some similaritieswith what they’ve seen happen in Melbourne, and whether those could act like analogues for whatmight happen in New Zealand. We expect to get more droughts and when we do get rain it ispredicted to be more intense. The droughts that Melbourne suffers are useful for us to learn from.

There’s also a lot of research that gardens can do in the sustainability space around our owngardening practices, and how plants can be useful for various sustainability purposes. For example,we research plants that do well on green roofs. A green roof or a living roof is a structure thathas a very small amount of substrate on which you can grow plants. It might be on the top of abuilding, on a letter box, or on a carport, for example. Generally, the structure is built to haveplants growing on it. It’s pretty difficult to retrofit. A green roof is a way to capture rainfall as wellas helping to cool its environment. If every building in a big city had a green roof, the summertemperature would drop because of two things. First, the green surfaces absorb less heat from thesun. Secondly, the plants also cool the air by evaporating water.

A green roof also helps with capturing the water and slowing it down as opposed to it just fallingonto the road and into the stormwater. It also filters out some of the nasties in the water. A lotof green roofs have chains and different mechanisms where the water will slowly fall down thebuilding and then into the stormwater.

A lot of the research that comes out about green roofs is northern-hemisphere based, and a lot ofthose plant recommendations are weeds in New Zealand, so we’re doing our own work triallingnative and exotic plants. We’re also trialling plants that might be useful in swales, in filtering water,and in rain gardens. In our native roof, we’re trialling plants that are in similar conditions in the wildto those on a green roof, and theytend to be coastal plants, so somegrasses and some ground covers –plants that tolerate quick inundationand then lots of drying out. We’vegot a small list that we’re working onand will publish. In terms of exoticplants, they’re quite tricky and a lot ofsucculents tend to be a little bit weedyhere, so we’ve been trying plantslike bromeliads, ornamental garlic,some south African bulbs, irises andthe ice plants, Mesembryanthemumand Lampranthus.

Another great space for botanic gardens research is in bridging the biosecurity world with the gardening/horticultural world. A lot of botanic gardens are part of local councils or governments, and they tend to have weed policies. Auckland Council has banned the sale of agapanthus, which is a really popular plant and very common for stabilising banks, for example. But they get into native and wild areas very easily. New Zealand has a perfect climate for most weeds – we’re a bit like Hawaii! Unfortunately Auckland is a hot spot for weeds. So, in 2012 we initiated a project where we worked with Council biosecurity and the nursery industry to see if we could find a sterile form of agapanthus that we could recommend to the public to bridge that gap. We wanted to be able to say, yes, there are ‘bad’ agapanthus, but here are some that you can grow and sell and still support the nursery industry. We’ve been counting seed and looking at seed viability of different cultivars. We’ve now got a list of seven that have no or almost no fertility. We are also looking at the attractiveness of these seven to the public in terms of having nice flowers, as well as their horticultural merit and stabilising ability. It’s a really good model for partnerships and working with different industries on finding a common ground.

We’re also looking at sustainable approaches to gardening. We haven’t used chemicals on our plants for about 21 years. We trialled stopping at a time when we were growing the national collection of roses in New Zealand. Those roses were being heavily sprayed, including all the ones new to the market. We decided that spraying them wasn’t sustainable for the environment, as it was potentially affecting the soil community, among other issues. We used to spray on a fine, calm day when we probably had most of our visitors, so it was also not good for visitor or staff health. And it was expensive! So, we stopped spraying, which was quite controversial at the time. Perhaps surprisingly, the roses were fine without spray. We haven’t used any chemicals in the gardens since then. We continually monitor and evaluate our plants for their performance in terms of pests and diseases. We don’t keep anything that gets heavily infected. This shows home gardeners that they don’t have to use chemicals to have a healthy plant at home. We still grow just over 300 different cultivars of roses, mostly in a monoculture, and they’re very healthy. They get very little black spot; they might have the occasional aphid but nothing that decimates them. We’ve shown that roses don’t need to be grown using chemicals (at least in Auckland) and that’s really cool! The team evaluating the horticultural merit of sterile agapanthus.

Another aspect of our sustainability research is sustainable water management. At the gardens we’ve got what we call a sustainable water trail, which is a series of different water treatment devices throughout the site that help to treat the water that we use. Our water flows into a natural stream at the bottom of the site. We’ve got a rain garden around the car park that captures all the water, filters out the nasties in the water and slows it down. The water percolates the site throughout these different water treatment devices, such as swales or wetland. Sometimes we’ve got permeable surfaces to also capture water into lawn so it’s not just running off onto paths. A lot of these devices are useful for other people to come and see in situ. We get a lot of big companies visiting who are required to install water treatment devices in their new developments, so this enables them to see the devices in practice and the kind of plants we use, and how it all works. The trail is a good education tool, but also a research tool. We’ve got a researcher who comes in regularly to check on how the trail is doing through, for example, soil testing.

I think what sets us apart from others is that our research gets filtered down into the advice we give to the public. We hold a lot of workshops, engaging with the public around what to grow and how to grow it at home, so a core part of our research really does filter into the public domain. Scientific articles from our trials are turned into glossy brochures for the public (‘Plants for Auckland’), with eight plants recommended per plant group. In addition, our website has an online ‘Plants for Auckland’ searchable database containing these plants.

A lot of other gardens sometimes struggle with sourcing plants. I think our plant recommendations are valuable as they lead to public demand for these plants. This will in turn drive demand in the horticultural/nursery industry to grow these plants, making them more widely available.

Are research partnerships important to you?

Hugely. Because we don’t have a big research team, it’s really important for us to work on partnerships, such as external government research agencies like Landcare Research and Plant & Food. We tend to work with them on projects such as myrtle rust and kauri dieback. They might use our site for sampling of plant material or soil, or they might use our nursery facilities for various experiments. Our nursery is accredited under a New Zealand biosecurity scheme, so we have high hygiene protocols. A lot of the plants we grow are not just for the gardens – we grow 65,000 plants a year for revegetation, so we need to make sure our plants are clean. That’s why researchers like using us as a site because they know our nurseries are clean and the plants we provide are valuable for their research.

We also provide material for projects we see value in, suchas the Lophomyrtus (a genus of the myrtle family) cultivartrial we attempted. Lophomyrtus is heavily affected bymyrtle rust. All the cultivars became infected with myrtlerust in the nursery, so perhaps growing highly susceptiblespecies in Auckland is not ideal! All was not lost, however,as we were able to give some samples to a researcherto learn more about the disease and how it behaves onthese plants.

What is your vision for the future of plant science research at the gardens?

To become more involved in global conservation, at least between Australia and New Zealand. For example, we maintain several plants in our collection that are threatened. We often have only one individual and we don’t know much about its genetics. This is probably something the BCARM group through BGANZ can help facilitate.

We are also expanding our research into sustainable meadows. They are really popular in the northern hemisphere due to their pretty wildflowers, but we don’t have a similar native ecosystem. We’re looking at meadows as a sort of lawn substitute. We want to reduce lawn mowing and still provide usable spaces that people find attractive, and that also provide additional benefits such as habitats for more plants, birds and bugs, and that are better at soaking up rainwater. New Zealanders take real pride in their lawns and are always out mowing noisily at 7am on a Saturday! We’d like to reduce our inputs into our lawns, such as mowing, if possible, and growing a meadow could be the answer. We have a PhD student starting this year who will investigate this. Sustainable meadows are not planted with flowers but are managed (by mowing or soil fertility) to make conditions less suitable for grasses and more suitable for flowering herbs. The research focuses on ways to encourage more of the shorter plants with plenty of flowers in the lawn, not ‘long grass’. We are testing mowing at different frequencies (for example, once a year, once every two months, once after flowering) as well as seeing if we can lower the fertility of the soil (there is evidence diverse meadows are encouraged by low soil fertility). The student will also engage in a lot of social work around what kind of messaging we can use to change people’s perception of what a lawn should be − an unmown lawn might not be the sign of neglect that some people think it is!

Another area in which we are very interested is options for good street trees, especially in terms of climate change. Lot of our street trees are not doing well anymore. I think partnering with the University and another botanic gardens that have some experience in climate modelling would be really useful for us. One of the key comments from our annual visitor survey is that people want more shade, so picking the right tree for the right place is something we need to work on. We’ve had some initial conversations with RBGV Melbourne but if anyone reading this is interested in helping us, please get in touch.

And in your spare time, what are you reading, watching or listening to?

To be honest, I’ve been listening to puppy podcasts because I’ve just got a border collie. I’m trying to figure out how to stop her eating my garden and how to stop her jumping on the couch! I’ve also been catching up on the new science video series from RBG Sydney, ‘What the flora!?’, https://www.rbgsyd.nsw.gov.au/science/what-the-flora-!

Finally, what’s your favourite plant, and why?

I usually say I have a favourite group of plants and that’s orchids, but it’s just because I’m biased from my master degree! I also love magnolias. My dream is to have a lawn full of dark purple and pink magnolias. The colour of the flowers is what really attracts me. The way they attract pollinators is also fascinating – the flowers actually warm up to attract beetles, their pollinators. The magnolia family is pretty cool in terms of evolution as they’re one of the first flowering plant families to have evolved, around 60 million years ago. So I’m attracted to them both visually and scientifically!