I live in Australia.  “A land of droughts and flooding rains” (D. Mackellar) and this summer devastating bushfires.

Let’s be clear.  Bushfire is not new.  Even devastating bushfire is not new.  It is part of our landscape and our ecological uniqueness is dependent upon this mechanism for persistence and renewal.

However, the summer of 2019/20 is now etched into the minds of every Australian, everywhere for all the wrong reasons.  It is beginning to be known as “The Black Summer”.  When I first started writing this blog at the beginning of 2020, bushfire has moved through our country in an unprecedented fashion.  Fiercely, with enormous scale, unpredictability and with devastation for people, places and our wildlife.

Is this the new normal?  A question posed by the public, and responded to by the scientific community and our firefighters.

From an ecological perspective, let’s break down “The New Normal”.

We often think of nature as stable.  Resilience is high and therefore ability to respond to pressures is strong and so the system returns to equilibrium after disturbance.  In face disturbance is healthy in building the resilience of a system.  After a bushfire, plants regrow, animals breed, systems rebuild.  Nature fixes itself – right?

Well the problem is that resistance and resilience are not infinite.  Seemingly minor changes on mass can disrupt stability until you get to a big change or, a significant change can shift a whole ecosystem.  This is further complicated by other factors that make the continuum of any ecological system not a simple point A to point B, but a journey responding to other factors within and outside of the ecological system along with the initial pressure that un-stabilised the system to begin with.

Think of it like moving through a house full of doors.  As soon as you move through one door, it closes.  The wind blows it shut, someone locks it, the handle falls off…whatever, the point is you can’t go back through it again…. and when it finally opens, someone has changed the curtains and carpet.  Same house, but different.

However, the difference with an ecological tipping point is that the changes are long lasting and difficult to reverse.  Not so much a change of curtains and carpet but a full renovation.

With this view, nothing can every remain truly stable indefinitely or go back the same.  Therefore, when an ecological system reaches a tipping point, where a change to a new state is highly likely due to pressures, it is also unlikely that the ecological system will return to its previous state.

In Australian landscapes I use the rabbit example.  During the late 1800s and early 1900s there was a rabbit plague in the eastern Australian states.  In some areas, the ecological damage that the rabbits inflicted on the landscape was so significant that even when the plague was under control, the landscape in some areas did not recover.  The rabbits grazed plants to the point where they could not recover.  With no green leaves to convert solar energy into growth and root development, the precious plants keeping our soils together died and entire plant communities became locally extinct.  With organic matter lost from the soil, the capacity of the soil to hold together was weakened, water holding capacity of soils reduced and precious nutrients were removed through soil erosion.  The result being an altered state with feedbacks such loss of topsoil and increased rainfall runoff preventing a return to the previous state.

Further, our land management decisions influenced by economics, politics and social factors change over time.  The way we farmed in 1920 is different to 1940, to 1960 to 1980 etc.  These are social, economic and political factors outside of the ecological system that still have influence over how it functions.

Back to the Black Summer and the possibility of our New Normal.  Knowing that resilience is not infinite, can we explain the current events as transition into a new normal?  There will no doubt be much written in this space, but perhaps the best indicator will be time.

 

MORE:

Feature Image:

Artwork ‘New Growth’ by Janelle Amos donated to the Australian Bushfire Relief

https://www.selfpollinate.com/

Tipping Points:

https://biodiversity.europa.eu/topics/tipping-points

Resilience Video:

https://www.stockholmresilience.org/research/research-news/2015-02-19-what-is-resilience.html

Poetry:

“My Country” Dorethea Mackellar

The New Normal Media:

https://www.nytimes.com/2020/01/02/opinion/climate-change-australia.html

https://www.smh.com.au/environment/climate-change/these-are-the-future-fires-californian-fire-chief-says-australia-is-facing-the-new-normal-20191112-p539tl.html