Conversation between artist Elizabeth Demaray and Igor Bronz, Engineer / Project Manager, Gaia Technologies LLP, Gaiatechnologiesllp.com on the Manhattan Tundra Project, 1/14/2020

IB: We need to green 50% of all buildings in NYC inorder to counteract the urban heat island effect/

ED: okay, so I’m going to describe the Manhattan Tundra Project to you and then I’m going to ask some questions about soil and some questions about the ways that this project might be able to help you. Art/sci collaborations can garner lots of publicity and it will be a different kind of publicity than you might get from a public planning project or science research.

In terms of background, as an artist, I’m really interested in figuring out how to use the built environment to collaborate with other lifeforms and I think that the built environment is turning into a new kind of ecosystem all by itself. I currently have an extraordinary studio residency at the World Trade 3 building. I’m on the 70th floor. Last year I had a residency at the World Trade 4 building and I was on the 68th floor. It is amazing up here because I’m above all of the other modernist skyscrapers that were built over the course of the last century. And what you see, looking down on the tops of all the other modernist buildings around me, that there are all of these empty rooftops that people are not allowed to go on. These big square boxy buildings have flat area on the very top. These areas usually house maintenance equipment, so fans and generators and things like, that also big spaces that are carefully covered with tar and gravel. 

Looking down on these roof-tops from my fancy studio at World Trade I realized that these buildings had never been designed for people to see them from above.  The other thing that I thought was really amazing they are these empty spaces that are open to the elements but not to humans. So, I started to think about the kinds of interesting habitats that these areas could be for our companion species. I’m particularly interested in ecospaces where humans are not allowed to go. It occurred to me that we could to just put 8 in of topsoil on the tops of these buildings and then simply see what other life-forms show up and are able to sustain temselves at that height.  I started calling the project the Manhattan Tundra Project. As you know the height of a tundra landscape is much higher that a typical skyscraper, but I like the idea of that these buildings offer us and the other life forms in our shared ecosystem a new higher space to inhabit. So, the Manhattan Tundra involves putting topsoil on the tops of these buildings along with a webcam computer vision system. That way everybody living or working in the building is able to log on and watch whatever type of emergent ecosystem evolves. I’m basically trying to get urban dwellers to watch grass grow. I’m also planning to put some very large, very long flat screens down in the building entrances, so that urban dwellers can watch a slow, long-term, video feed of what’s going on in these little spaces. 

So, could you tell me about your soil what it’s made out of and how heavy it is and if it might be applicable to the Tundra Project?

IB: We produce GaiaSoil which is an ultra-lightweight green roof soil media that is essentially made up of recycled styrofoam, compost, clay and a special type of pectin that allows microbes to grow in it and it functions better than most top soil. My colleague and GaiaSoil inventor Paul Mankiewicz discovered that the limiting control for plant growth is availability of air within the soil so you want to have a soil or any sort of medium that has a high porosity. This stuff weighs weighs about 12 pounds per cubic foot which is a lot lighter than a typical topsoil which weighs about 85 lb per cubic foot fully dry. Talking about saturation, you can’t change the weight of water so GaiaSoil ends up weighing 34 lb per cubic foot compared to about a 110 lbs for topsoil. Our stuff is pretty ideal prefer for something like this because as you mention the rooftops are not designed for people or recreational activity so they are not really reinforced for that. Whenever you are designing a building with a rooftop you want you really want to know what is going to be on that roof because if you’re planning on having people up there you have to really increase the load bearing capacity of that to accommodate the extra weight

ED: That sounds amazing. My first question is about weight. it’s very windy on the tops of skyscrapers and one of the issues is that you’ve got to make sure that whatever you put out there is not going to blow off.  Do you use some kind of netting or a monofilament fiber structure in the soil?

IB: Oh absolutely, so GaiaSoil was specifically designed for rooftops and we have had issues in the past with a soil wanting to blow off the roof so the way we dealt with that was as you mentioned would you have a kind of netting that we place on the soil but when it’s placed on the roof before it has anything growing in it from blowing away. We use either a Jute coconut fiber net or burlap both of which are biodegradable so it keeps the soil on the roof while the plants have a chance to grow and eventually it just decomposes and supplies the soil with nutrients. Mature plants are able to hold the soil together with their own root structure

ED: Wow! I specifically like the way that the structure actually goes away and/or becomes incorporated in the system. I’m going to guess that you all have done some experiments with the kinds of plants that work best in terms of structure. What kinds of plants are they? How long is the growing time? And are they indigenous life-forms?

IB: Absolutely. The plants we use are always native to the area where they green roof is because we don’t contribute to an invasive plant spreading from our roof to other roof or gardens. We take the whole ecosystem very seriously. Our roofs have tall grasses and leafy plants -we prefer plants that have a leaf area index of a 3 or higher meaning that the total area of the leaves and plant surfaces is three times higher than the footprint of the plant itself. We have a number of roofs that are fully developed that you can see for yourself. We have the Linda Tool Green Roof in Red Hook, the Einstein Green Roof at the Albert Einstein Medical School. We have several green roofs on the 5 Boro maintenance facility on Randall’s Island that’s owned by the New York City Parks and Recreation. That building probably has the highest number of unique green infrastructure projects anywhere in the world. They have something like 30 types of green roofs on their roof by different manufacturers, using different styles. We definitely have these roofs already in existence and I like I’ll be happy to take you on a trip there. I’m good friends with Max Lerner who manages the sustainability for New York City Park who would be happy to give us a tour.

ED: I am I am so excited to see these rooftops! I have a question, could you possibly insert a picture of each of those rooftops with the addresses into this document? Of course, I am really excited to see the kinds of plants that have been recommended, particularly in relationship to the pollinator insects. I had the pleasure of learning a little bit about Monarch Butterfly migration. They, and other migrating species, look for plant color on the ground doing flyovers. For the Manhattan Tundra Project, it would be great to use some kind of netting that would stay in place for maybe five years. I would probably also have to build some sort of infrastructure for water retention. Do you have any thoughts about how to do that? 

IB: I’ve actually never heard of anybody putting a green roof on a skyscraper before. So I’m very interested in to see what will happen because a tundra is a continuous high elevation landscape, but the urban landscape with skyscrapers has these extremely high elevation differences. You can go from street level to fifteen hundred feet up and that’s actually really interesting from a research perspective. I’m thrilled that you’re taking the initiative on this. As for water retention, one of our roofs, B’nai Jeshurun, is a roof on the synagogue on the upper west side. They wanted a deep soil substrate just on the edges so we constructed deep planters made of wood that have about a foot of GaiaSoil and the capacity to accommodate another foot of water. GaiaSoil is lighter than water so you can’t overwater it – let’s say 5 times more water by volume that there is GaiaSoil, what will end up happening is that the soil will float up with all the roots holding the soil together, and the water is going to create a reservoir below the soil substrate. The plants are the ones who decide how much water they need and will pull up more water through the soil structure as they use it. How much water you want to put in there and how deep this container depends on how the water will be supplied to the building, whether it’s through overhead rainfall, through a separate storm drain or from the grey water of the building itself. It also depends on the load bearing capacity of the roof itself to hold all that water at a given time, so the maximum reservoir capacity needs to take that into account.  

ED: Everything that you’re telling me about this soil makes me think that it is really ideally suited for urban spaces. I especially like the fact that it creates its own reservoir underneath. It occurs to me that this is a lot like the self-watering gardens that people are now engineering. It’s wonderful because it’s a super great way of sequestering water in your landscape. This is turn is a great way to keep your city nice and cool during heat spells. I also like the idea of using the natural runoff from the rooftops.  You could also basically dictate how deep your reservoir would be underneath your soil. 

In terms of these spaces becoming more like islands, I’m interested in the idea of something called a biotope. A bioscope is a small ecosystem that is usually shared by number of species. These groupings often included humans. So I’m really interested in the kinds of  biotopes that might exist on in buildings that are adjacent to each other. I’m also interested in the way that an ecosystem basically self-identifies the kinds of life forms that it’s applicable to. There are also other environmental factors that are prominent in these kinds of situations. One is that you get extreme variations of temperature at these heights. So, not only do these life-forms have to exist at high altitudes, but they’ve got to have a nice wide temperature range.

Off the top of your head, if we were going to be doing say an area of 40 by 40 square feet of topsoil, how much of a reservoir would you imagine that would be needed for water underneath? I’m thinking that we would want the system to support sod type grasses.

IB: Sod grasses don’t really need much of a reservoir, they can function just from the capillary water within the soil however if the water is going to come from the gray water system then you don’t really need any reservoir at all because the flow will be very frequent but if you expect rain to be infrequent like when we had three weeks of no rainfall a few months ago, we don’t want the grass to die or get very wilted as that will influence the types of organisms that going to exist on that roof so I’d say maybe a few inches will definitely be enough for the rooftop. It would be interesting to have nests for eagles and falcons as well due to the buildings’ great heights. 

ED: Yes, I have! I’m actually doing a project right now called The Shelter Project: nesting in the built environment where we’re making nesting boxes for native birds and bats out of old single mold Econoline suitcases and other forms of human detritus. So yes, I’ve been thinking a lot about this and I’m proposing some sculptures a little lower to the ground in the vacinity of lower Manhattan. There is also some amazing work that’s been done looking at the spots where birds of prey and migratory birds gather before crossing water. So I love the idea of putting some nesting boxes in the Tundra Project. I think that’s a wonderful reason for people to log on and watch. As an aside, I’m not the first artist that has thought about migration patterns in relationship to tall buildings. There have been extraordinary artist like Lynn Hull working in this area for some time. 

I do however have some basic questions about green roofs.  What would you do in a 40 by 40 square foot space on the top of a modernist building that didn’t automatically have its own runoff water system? 

BI: The way we waterproof the planter or the roof itself has to do with the size of the roof or container, so if we if we’re planting soil into boxes for planters then you can line it with waterproof geotextile or even a plastic tarp.  40 x 40 is 1600 square feet which is a fairly small green roof, which can be waterproofed with something called polyurea, which is a type of spray on waterproof coating. Its about a few millimeters thick, has a 30-year lifespan guaranteed by the manufacturer to waterproof a roof. Many roofs have waterproofing issues which can potentially cause a leak so the benefit of polyurea is that since its spray-on, it goes into all the cracks and its durable enough to not get ripped through. It adheres to the roof like paint, so that there’s no chance of there ever being a leak and we’ve used polyurea for number of our green roofs and some of them have been around for over 10 years such as Linda Tool, which has not had a single leak in its lifespan.

ED: This is great! I actually love the idea of your green roof helping to insulate your building from leaks. That’s absolutely wonderful. So I have another question for you. I’m very interested in finding out on the kinds of lifeforms that would simply show up in an emergent ecosystem. I’d actually like to find scientists who are interested in studying these kinds of systems. What would be good for your company to look at in relation to this project? What would you be interested in studying or seeing in this kind of framework? 

IB: I think this would be a very fascinating in and of itself, and helps move the dial further in developing the scalability of green infrastructure in general. We won the Access Cities Open Innovation Call on Air Pollution and Urban Heat Island Effect competition for our ideas on how to scale green spaces in the urban environment to change the urban climate, but the trend for urban development seems to be “buildings up” -you want higher density and tall buildings are more efficient when you have limited space, but because you have more tall steel-and-glass skyscrapers, its harder to integrate green infrastructure into them. We typically put green roofs and green walls on short buildings and buildings that are built using an older style because of their large roofs, high load bearing capacities and sheer concrete or brick facades. Its trickier to adapt our own technology to skyscrapers because the roof of a skyscraper is so small compared to the overall structure of the building. We want to utilize more of the building in some way, such as its vast vertical components. Your research is critical in defining what can grow at high altitudes as well, which is challenging when attempting to place high altitude green walls as well. We can only hypothesize, and I’m not a biologist by any means, but Paul is definitely a biologist of renown and can answer your questions about the life forms that could be there but of course nobody really knows until it’s done. A green roof on a skyscraper can function as a reservoir, or perhaps I should use the term “water capacitor” because we want to eventually be able to put a green wall on a skyscraper but it will need to be fed with water from somewhere and a green roof is much more effective as storing water than a green wall. Due to high winds and lack of substrate, green walls need to be irrigated in some manner, and the green roof could be the source of that irrigation. A significant challenge is being able to greenify the skin of skyscrapers, and this could be one of the solutions to doing so. 

ED: So here’s my thought, if you could fill in information about Gaius, I think the Manhattan Tundra Project would be a really nice way to frame your soil. I’m currently doing a project at Monmouth University which is much lower to the ground, but I think would be a really nice way to use your soil with students. I also want to mention a project in 2011 that was called the Lichen for Skyscrapers Project  where I simply started culturing lichen on the sides of skyscrapers. I did this for a festival called Art in Odd Places on 14th Street in NYC. As part of the artwork, I sent form letters to the buildings in the vicinity of 14th Street. Of course, nobody got back to me about smearing slurry on sides of their buildings. Luckily, I found a building that was owned by artists who were participating in the festival where I was able to do a planting.  I also ended up doing walking tours where myself and an amazing biologist, who was interested in lichen, took people on walking tours of the city to see lichens. At the end of the walks, we would teach everybody how to make lichen slurry. We also gave out baggies of lichen slurry to everybody on the tours who lived or worked in a high-rise. My students began to call this lichafetti because the cool thing about lichen slurry is that you don’t need permission to plant it. You only have to get a window open a couple inches, just enough to get your wrist outside in order to smear slurry on the building’s exterior. The great thing about lichafetti is that if the lichen doesn’t take, it will dry up and blow away to propagate somewhere else. I’m currently working on ceramic tiles that will support large scale propagation.

IB: First of all I want to say that I think they like the idea is fantastic and I don’t know if you’re away of this but lichens save lives, because they have an incredibly dense structure and a huge surface areas on vertical surfaces and especially street canyons. What ends up happening is that you get all this air pollution coming from car exhaust and other sources and as the wind blows the air pollution around, especially particulate matter 2.5, which is particularly harmful to people as its one of the reasons why they say that a person living in the city their whole life has the lungs of a smoker, the lichens end up trapping particulate matter and other solid air pollutants, which are then washed off by the rain, dew and wall runoff thereby taking it out of the air and flushing it into the drain. Actually we just with New York City Parks a few weeks ago and they were asking us for designs of how to implement moss and lichen on green roofs in systems that can essentially maximize its surface area so that you can remove more air pollutants. GaiaSoil is a patented product and we’re the only licensed producer, but I’m sure we can just deliver it to you for free generally. It’s not very expensive ($150 per cubic yard) which is about the same price that you have for other green roof media. We produce GaiaSoil in our facility in New Jersey. We can have the soil delivered in about one or two weeks, especially since it’s not a huge amount. We’ve had orders for like 70 yards of soil which requires multiple 53-foot trailers to deliver. This one can be delivered with a fairly quick turnaround.

ED: Wow! How much would we need for a 10 ft X 10 ft. area?

IB: 10 by 10 foot side is 100 feet so that would require let’s say six inches of GaiaSoil, so we’re looking at about 50 cubic feet of soil or 2 cubic yards which is not a large delivery. Volume wise, it’s almost like a planter so I would recommend building a planter the area where you want to put that soil. A 10 by 10 foot wooden box with a 1.5 foot high edge should do the trick, to accommodate any rise in soil level due to water, waterproofed using geotextile or tarp and secured flush to the edge (the weight of the soil will fill it out). The edge of the geotextile or tarp should go over the wall of the siding, and nailed into the wood to secure it but only from the outside. Don’t nail it on the inside of the planter so as not to puncture the waterproof liner. 

ED: Excellent! It sounds like a plan.