By Michael Spackman
Landscape Architect  spackmanmossopmichaels.com
and Felix Oppen
Designer & Publisher of Ligature Journal

On a side street just off King Street that runs through Newtown in Sydney’s Inner West, is a plot of land that is occasionally used as a parking lot. About a third of the plot is slowly being overrun by vegetation. You can see from the picture(s) that it is a mixture of native and introduced species. Nothing here was planted. This reasonably lush ecosystem has grown up over only a year or two and looks after itself. It is a new—or what is called a novel—ecosystem and has occurred quite naturally.

If you were to ask people what they believed were the key characteristics of a ‘natural’ environment and a ‘wild’ environment you would probably find that a key descriptor related to the level of human intervention; the less intervention, the more natural and wild the environment. The problem with this is that there is almost nowhere on the entire planet that, under these criteria, can be described as either truly wild or natural. Humans have been manipulating ecosystems for millennia. It is also inescapable that we humans are intrinsically part of the same systems.

Consider these scenarios; you are driving down a country road and on one side there is a field that has been left unused for a while. It is filled with fibrous plants and is in flower—the sea of purple flowers tell you it’s Paterson’s Curse. Among these plants occasionally are self-seeded eucalyptus seedlings. A little further along there is another field of mown or grazed grass. In one corner there is a patch of blackberry in fruit. Native birds that would previously have been eating the fruits of the now-cleared indigenous vegetation are eating the berries. Later you are travelling past the edges of some forest. You see a mass of lantana between the trees. You can’t see them, but inside the lantana, native animals have made their home as is protects them from foxes and feral cats. Each of the plants specifically mentioned here are weeds and under current thinking should be eradicated. Each of these small ecosystems are also, to some extent at least, novel. Nature has adapted with minimal energy input and found a way of utilising these invaders.

So what is a novel ecosystem?

Put simply they are ecosystems that are the result of deliberate or inadvertent human action, but do not depend on continued human intervention for their maintenance. From this definition we can understand novelty to refer to new species combinations, with the potential changes in ecosystem functioning.

Perhaps one of the key ideas sitting behind current theories of novel ecosystems is that it is about letting the ecosystem speak for itself, to give it a space and time voice to tell us what will grow in these environments we have created. Many human societies have spent a very long time dictating to nature what it should look like, what is wild, what is natural and what is nature tamed. The novel in the concept of novel ecosystems is to flip this around and to let the ecosystems now tell us what works. This is quite a paradigm shift, and it suggests that the approach is not a dumbing down, or a giving up that just lets things go to wrack and ruin, but instead to step back and work with what thrives in an ecosystem rather than against it.

Working with novel ecosystems is not about sitting back and doing nothing. It is, however, about accepting that we are part of nature, we influence it, our actions have and have had consequences, that we are influenced by nature and that it has limits. In accepting this we are acknowledging that we as humans have created new environments that require new—novel—ecosystems to be and remain habitable.

Current (AD 2000) extent of novel terrestrial ecosystems, estimated as unused lands within used grid cells based on the HYDE 3.1 dataset (not significantly distinct from KKl0). Areas estimated as 100% used (‘Extensive’ use) or without evidence of human populations or land use (‘Wild’) are highlighted separately; these landscapes likely also include novel ecosystems as a result of underestimation of human presence, species invasions and environmental change (‘Wild’), and failure to account for smaller unused areas embedded within used grid cells. Eckert IV projection. From Novel Ecosystems: Intervening in the New Ecological World Order, First Edition. Edited by Richard J. Hobbs, Eric S. Higgs, and Carol M. Hall. © 2013 John Wiley & Sons, Ltd. Published 2013 by John Wiley & Sons, Ltd.

In considering the value of novel ecosystems we need to reconsider many things, including what we define as weeds. We tend to think of plants introduced from other countries—exotic species—more easily as weeds than native plants. However, there is a difference between native and indigenous flora (and fauna for that matter). The latter is a plant that is from the area/environment that is under discussion. Native plants can be from elsewhere in the country and might be classed as weeds when planted outside the area to which they were indigenous and if they are out competing actual indigenous species.

In considering the value of novel ecosystems we need to reconsider many things, including what we define as weeds. We tend to think of plants introduced from other countries—exotic species—more easily as weeds than native plants. However, there is a difference between native and indigenous flora (and fauna for that matter). The latter is a plant that is from the area/environment that is under discussion. Native plants can be from elsewhere in the country and might be classed as weeds when planted outside the area to which they were indigenous and if they are out competing actual indigenous species.

We also need to look again, when we want to bring ‘nature’ back into an area, or to reintroduce ‘nature’ to an area marked for rehabilitation, at what we can actually achieve. A city is a totally artificial environment and reintroducing plant life to it to recreate a semblance of ‘what was there before’ is problematic. Can we recreate the original wild landscape without actually removing the city completely? For that matter do we really know what was there in its totality ‘before’? And what ‘before are we referring to—before the city was built, before white settlers arrived in the area and turned the landscape into farmland? before First Nations peoples arrived?

If we insist on trying to recreate a version of what was there before, we will at best create what we can really only call a heritage eco-system, an ecosystem that refers to some past idyll but is no more ‘natural’ than if we had just planted without reference to a theoretical ecosystem from the past. Chances are, that because what we are trying to create is in an environment for which many of the plants we are using are no longer suited, it will be necessary to pour in considerable resources to maintain this now artificial ecosystem. And as soon as those resources are reduced the ecosystem will again begin to hybridise, and transition towards the novel.

The question now is, that’s all very well but what is the benefit to us?

Novel Ecosystems & Urban Renewal

Novel ecosystems are potentially extremely useful in that major novel environment, eco-logically speaking, the city. A practical and immediate example is an urban project currently in development that Sydney & USA landscape architecture practice, Spackman Mossop Michaels (SMM) is working on in Detroit, Michigan.

Since its heyday in the last century as ‘Motor City’. Detroit has been in decline, and during the global financial crisis of 2007-2008, the city was declared bankrupt. Many neighbourhoods in the city are neglected, with numerous empty lots and burned out, dilapidated structures. The landscape is blighted, it is a depressing place to be, and the city has extremely limited resources to work with.

The SMM project is a quarter-square-mile pilot for the transformation of Detroit. Known as the Fitzgerald Neighborhood Stewardship Plan, it entails working closely with the residents of the neighbourhood, from initial ideation throughout the whole process. The project aims, through the exploration of landscape typologies, species selection, planting and management, to develop urban design strategies that will, with the on-going engagement of the neighbourhood communities, revitalise and rehabilitate the physical environment and with it the social and economic environments.

Novel Ecosystems & potential for climate change mitigation

On the 12th of May 2021 The Guardian news-paper reported that in a survey of 800 cities around the world, a quarter lacked the finances to protect themselves from the effects of climate change. If we go back to the definition of the novel ecosystem, that they do not depend on continued human intervention for their maintenance, we see that we have a mechanism for potential climate change mitigation at minimal cost.

For Australian cities, one of the big problems caused by climate change is heat. Cities generally are hot places and in places like western Sydney this is likely to become increasingly acute as summer temperatures will regularly exceed 45°C. Temperatures that are actually hostile to human life.

Australia is a warm and dry country which means many native species have evolved to cope with this, the net result being that they are not particularly good at providing shade on the scale that cities need for cooling. As it happens, what cities need for cooling are broadleaf trees—the sorts that are classed as introduced, exotic and weeds. Fortunately, some of these also seem to thrive in city environments in ways that native species do not, creating a novel environment that functions for the inhabitants.

With the climate changing more rapidly than natural evolution can cope with, there is only a certain amount that can be done with science to accelerate adaption, but the pace may be too slow. Beginning with a look at the existing novel environment and ‘let’s see what survives’ in the city can streamline the select-ion of species for further research. Creating ecosystems based around not where cooling it provides (and we are talking about upwards of 5°C here, which is significant and potentially lifesaving) and how well is survives in the novel ecosystem of the city without artificial re­sources may give us a cost effective and mean­ingful chance at survival in the cities in which we live.

We humans have been part of the global ecosystems for the entirety of our existence. Our actions mean that much of the world is to some extent novel. While ‘[t]hese systems are a manifestation of ongoing evolutionary change in ecosystem and species assemblages.’ (Hobbs, 2013), we have been unwittingly creating novel environments (eg. cities) and increasingly novel climates. The net result is an increasingly unstable and, for us, hostile global environment. Active engagement with ideas around novel ecosystems is a key piece in the puzzle of how we might rebalance these systems.

References

Harvey, Fiona. One in four cities cannot afford climate crisis protection measures – study. The Guardian, 12 May 2021. (Accessed: 16/06/2021)

Hobbs, Richard J, Higgs, Eric, and Harris, James A. ‘Novel Ecosystems: Implications for Conservation and Restoration’. Trends in Ecology & Evolution (Amsterdam) 24, no. 11 (2009): 599–605. (Accessed doi:10.1016/j.tree.2009.05.012)

Lachmund, Jens. ‘The metabolic city and the city of biotopes: Paul Duvigneaud and Herbert Sukkop.’ In The Botanical City, edited by Matthew Gandy and Sandra Jasper, 22-29. Berlin: JOVIS Verlag, 2020.

von der Lippe, Moritz. ‘Vegetation as testimony: botanical traces of the urban past.’ In The Botanical City, edited by Matthew Gandy and Sandra Jasper, 46-53. Berlin: JOVIS Verlag, 2020.

Hobbs, R. J., Eric S. Higgs, and Carol. Hall. Novel Ecosystems: Intervening in the New Ecological World Order. Hoboken: Wiley, 2013.

Hamilton, Rebecca. Deeper History, Science and History come together in conserving the swamplands of southern Sydney. (Accessed 16/06/2021)

Groves, Richard, Can Some Australian Plants Be Invasive? Plant Protection Quarterly Vol.16(3) 2001 (Accessed 16/06/2021)

Header Image Caption

Untended and ignored plot of land in Newtown, Sydney. A mix of self-propagated plants including native (though possibly not indigenous) grasses and non-native like Pampas grass and a tree. Photo: Felix Oppen.