We love the country which is a beautiful thing.

But the bigger question can often be which tree or shrub do we plant and where do we plant them? To discuss Which Plant Where I'm pleased to be joined by the Inner West Council's Urban Forest Manager, Gwilym Griffiths, once again and Program Manager from Macquarie University, Leigh Staas. Welcome to both of you.

Thanks for having us.

It's great to have you back. Leigh, perhaps you first. Can you outline the scope of the Which Plant Where program what's driving that research?

Yes sure. It's a collaborative project between Macquarie University, Western Sydney University, the Office of Environment and Heritage and Hort Innovation.

And what we're trying to do is figure out what plants we should be putting in our urban landscapes not only now, but under a changing climate, which is no small issue is it because having had a look at the video that that Guillermo sent me I mean there's there's a lot of challenges out there.

There are a lot of challenges and really what it's especially because our cities are dynamic and ever-evolving and changing and we can starting to compete for space due to population change and increased urbanisation, and things like that are really putting pressures on our urban cities. What we're trying to do is figure out with the space that we have left how can we create liveable cities so that our plants actually survive - not only survive but thrive - which takes us to that they think getting your hands in the dirt kind of thing.

The Living Lab at Summer Hill is part of this research group and can tell us why Inner West Council has become involved in the program?

Yeah sure. Well for the exact reasons Leigh just mentioned space is getting harder and harder to find to plant trees an enormous council plants around a thousand trees a year. So we want to make sure that we're getting that right. You know that's a significant investment in the right place exactly and maximising their benefits.

So yeah when we plant a tree there's obviously an investment in that and we want to make sure that we maximise that investment. But I suppose the challenges are just getting more and more like it's not just space. It's also the climate factor with it you know establishing trees is actually the hardest part of all this actually planting the trees the easy bit, it's keeping it a lot keeping alive is watering it's establishing that it's getting it through its first two years of life.

And so if we're picking species that are the most resilient to these new climate conditions that are coming out that's going to see us in a better position.

I noticed I think during the last big, hot, dry spell we had a couple of years ago established trees like Banksias along the Cook River actually die like it was a water issue that we're getting and that has died and they were pretty established, is that a growing problem here?

Yeah it is.

That was your last season. You mentioned Banksia.

Yeah we did actually lose a lot. We lost about two dozen. They are quite sensitive to soil disturbance and soil issues. So potentially it could have been a drought and we wouldn't actually know. But yes that's one thing that we'd be looking at: do we plant more Banksias or do we put our money in a different species where we know we're going to get more resilience?

One of the things that has inspired gardens in local government I guess over the last 40 to 50 years has been the desire to see native plants in our area replacing the more formal English gardens and plants of an earlier era. More recently, of course, a lot of people have been focused on planting local native species an area in our area of course often source for the Willow Creek Valley or the impact of climate change be on local plants and you do that relates to local birds and insects. I don't know if that's your area?

So I know a little bit about it I'm not an expert but what we're finding so part of the project is we do bioclimatic modeling and we're looking at how species are going to shift and change where they can occur in the future. And there are some plants that are gaining ground of where they can be growing but then there's also a lot of plants several species that we're seeing that are reducing that where they can be grown.

And so what we're doing with the project is trying to identify species and they're not all native and that might upset some people but we need to be realistic about some of these things because climate change is becoming hotter and drier within our cities that the climate envelope is moving south. So if we're planting trees that are supposed to live 100-120 years that might not actually be suitable for our future landscapes. So we're looking at what plants we should be putting in that are going to be long-lived which is something which has not always necessarily natives. 

I think perhaps many people are aware of the issues around, you know, certain animal species running out of height because the temperature, they've been mountain species andthey've running out of mountain, probably ice goes only 2000 metres tall isn't it?

Is that the same thing with plants?. And a lot of them can't just get up and walk away. So we've really got to start thinking planning forward and deciding or figuring out creating confidence for people about what plants that they should be putting in that are going to be long-lived.

I think we're becoming more or more becoming more aware of the importance of shade trees. Yes. In reducing the heat island effect in big cities like Sydney with increasing global warming you have a different way to maintain trees.

I think some of the tree species in that video of people looking at were perhaps not quite as dense is so the coastal trees have been used to is that it is that an issue says that is that where trees from overseas come into play in terms of canopy saw keeping things cool in astronomical absolute what is an absolute essential part of having a liveable city is having a cool city.

So obviously our desire and a council is to plant the biggest tree and the most suitable location. So we try and plant took to the site. Obviously, if it's a small footpath we can't plant a big tree. But this program isn't especially identifying the size of a tree, it's more resilience of certain species.

The timing for this program is actually perfect so the council is actually done. Next year we'll be doing our street tree master plan. So the information that we gain from this research will be fed straight into that that will help guide species size of tree locations.

So does that I mean just looking at the very local effect here with things like the community nursery as a community centre. When we brought about the kind of trees the kind of plants and spaces that are available they will. That is the countries that is going to change over time.

You had to say that I think that they focused mostly on ground covers and shrubs not so much trees that the nursery. So I'm sure that some relationships that could be and some learnings from this program that could be shared there. But in terms of tree species perhaps not so much.

Okay so what are our cities going to look like in the future with trees as I know if you look at pictures right now in the inner west back in the early 70s when I was a little kid this area was just bare. There's barely a tree here. This. So we spent a lot of time in the last 40 50 years planting trees. Now let's be honest I know that council made a few mistakes along the way with all the best of intentions and effort. But a lot of true a lot of streets are fairly well triggered me to catch up. What's going to change over the next 20 years or so.

Well it would definitely approach to planting trees is that I mentioned before that the right tree in the right location. That's something we have to get right now. And things like strict tree master plans and urban forest strategies help deliver that that that promise. But I suppose it's also part of the message was actually from my point of view was actually made maintaining what we've got you know actually you know realizing that the existing canopy we have is very important. So we shouldn't just be focusing on planting trees. You just can't plant a 20. Exactly. Yes, a canopy takes it takes a lifetime to establish you know.

So you know we do have some phenomenal streets from legacy plantings a lot about in road brush box streets planted in the 1920s and 30s which people love. Exactly. And you know there's some of our best streets. I want one. Yeah exactly. I drive down some of them in matters. A lot of them in Marrickville have a have a field Ashfield with some great streets that you know we have our forefathers to thank. You know in the 20s and 30s. So it's about recognizing the value of them protecting them and also planning for their replacement and renewal. Moving forward some challenges there.

Leigh, for Sydney as a whole, are you're looking at that kind of thing in your research?

Yeah. So we're looking right across Australia and there are challenges each precinct. Each city have their own challenges. So South Australia has a challenge for heat. Perth has a challenge for it's like soils they have really low water and the soils they got they were very sandy soil Earth. Yes. So you know it's all about you know finding the right plant for that right space. So the project is very encompassing it's very complicated and very not complicated a bit complex. So we have to look at as a site whether it's so urban. A significant urban area to figure out what's going to be best for that space.

Other issues around monocultures as well avoiding that kind of thing.

Yes. So that's we really say the project is really trying to get diversity in the selection so people don't just do what they've done previously or they look at what the next council has done and plant the same trees. We want people to have a selection of trees. So then if we have a pest attack that all those plants don't just die or if we have a heatwave with a single species can't handle that heat and then that drought then they don't die and then we end up with nothing. So we are trying to incorporate that into decision making which is why we engage a lot with local councils and landscape architects and industry and the growers themselves to try and make sure that they think about these things.

Yeah big issues the Living Lab it's some of who I think you're both involved in a bit more about that getting the hands dirty stuff.

Yeah sure. Well there's actually multiple sites throughout the NSW area. The Underwood reserve someone who is was the first one. There's also a few streets. We've put these plantings in so we've select these sites based on trying to showcase a few various scenarios you know a park setting a street tree setting which have different impacts and challenges. So the Underwood. Underwood reserve has planted three trees there. And in this scenario there's an underground planting as well. So part of the trial is looking at how ground covers and plants underneath tree planting contribute to species success. You know in terms of associations with soil and healthy soils so under preserve showcases that Sara some of the streets just have playing trees just as we would. Trees in garden bed with just soil. So it's is looking at running the results on a few different scenarios to see what works the best thinking about how people can get involved.

Are we looking for a better engagement from the community both here in the West and around Australia to engage? I guess the way I've always looked at it is councils look after our streets on behalf of we as residents. Is that is a good way to think?

Absolutely. Councils always looking for ways to engage residents more around trees and a lot more work to do on our behalf. For that I suppose the point of this program is to help sort of show the community that we are you know we are thinking about this we're being strategic about how we plant trees to help how Brazilians in the future so that that issue because it seems to me that there's still a lot of fear in the community and you might be able in this to be around people fearing that branches will fall on them and the more damage their cars or what have you.

And perhaps some people don't yet quite appreciate the importance of trees in cooling our streets how we're reaching out to communities both in the West and around Australia on this issue. Is there a difference that you see in interstate in places like Adelaide where it gets really really hot.

So I think I think we're seeing the pendulum swing back a little bit. So people have been cutting down trees and we're starting to feel the temperatures rise and we're starting to realise that there is actual benefit in having straight trellis. Straight line trees and there were a lot of councils are putting in urban forestry and street tree plans master plans. So we're actually seeing that swing back with it. It's a difficult situation when people have an I guess it's lack of knowledge really about all the CO benefits and that's what these living lives are trying to do is to show the CO benefits not only for our health and well-being but also for biodiversity and creating liveable cities.

I'm just finishing up as we approach the news. If people do want to get involved more hands-on how can they do that?

Contact us and council. Send us an email. We've also got thoughts about this program to help people engage with it. But our email address is trees@innerwest.nsw.gov.au. Today you perhaps put that on your website so people can contact us and we're happy to talk about the program in more detail.

Yeah, cause I think you know people that may want to plant trees on the verge. 

Gwylim Griffiths is the Urban Forest Manager at Inner-West Council and Leigh Staas is Project Manager of this project from Macquarie University. And we thank you both for your time this morning. Did great. It's a really important issue. Thanks for having us.