Tuesday, January 22, 2013

Talking about Sustainability and our Forests

A little while ago a satirical graph on the use of the word "sustainable" made it's way around the internet via the National Association of Scholars.  It made me laugh because, as a student of sustainable land management at the time, I'd already become conscious of the fact that the word was being bandied around left, right and centre, without much thought to what it truly meant.

There are two definitions that tend to appear in the dictionary:
  1. able to be maintained at a certain level or rate
  2. conserving an ecological balance by avoiding depletion of natural resources
A key word that most often doesn't appear in the definitions is "resilience".  That is the ability to withstand stresses and recover quickly, or adapt to change.

When governments, organisations and corporations use the term "sustainable", they're often referring to the first definition.  Their desire is to be able to maintain the usage of a particular thing, such as our forests, at or above the current level of use for as long as possible.  This is directly related to their aim of maintaining monetary investment, profits, budgetary surpluses etc at or above the current level.

In essence, when these groups talk about something being "sustainable", they very often mean "it will continue to bring in profit".

The word "sustainable" is used to get the voters and consumers to stop thinking about the issue...  "Ah, logging of the old growth forests is sustainable, so it's obviously not something for me to worry about"...

For those of us concerned with the environment however, it is the second definition that we mean.  When we talk about our forests being "sustainable", we mean that they will continue to exist at least at the current level, or preferably be expanded.  Our main concern is about maintaining and enhancing ecosystem biodiversity through future generations.  And by that I don't mean in terms of human generations only, but in terms of the future of all life.

Continuing to use our forests as an example...

Forests can be defined in different ways depending on who does the defining: the definition can be used to fit whatever situation suits your needs.  At it's most basic it could be "an area covered with a dense growth of trees and undergrowth".  Although correct, this is a gross over-simplification.

A more accurate definition would be "an ecosystem, or collection of ecosystems, dominated by trees and other woody vegetation", yet that still does not really do a forest justice.  It is not until you understand what is meant by ecosystem that you can fully grasp the complexity that is a forest.

An ecosystem is a biological community of interacting organisms and their environment.  

A single tree is an ecosystem in it's own right, a forest a vast, far more complex ecosystem.  The organisms include every living thing, from the smallest soil microbe, through the insects, birds and mammals; and from the tiniest little fungal hyphae, through the groundcovers, shrubs, climbers and trees.  The environment includes the rocks, soil, water, air and everything in between.

Maintaining high levels of biodiversity in flora, fauna and the environment is where "resilience" comes into play.  The more diverse a forest ecosystem and the larger number of species (higher volume of biodiversity) present, the more resilient the forest is.  

For high levels of biodiversity to be maintained in a forest, you need to ensure that a wide variety of habitats are provided.  At the basic level, in a forest this will mean soil, organic matter on top of the soil, groundcovers, shrubs of various heights, trees of various heights, sizes and ages.  All these things and many more are required to ensure you provide varying habitats.  

If you selectively log only trees of a certain species and height from an area of forest, say only the Mountain Ash trees that regrew after the 1939 bushfires, then you are reducing the available habitat for select species.  Less habitat, means reduced numbers and this means more inbreeding and lower genetic diversity.

If you clearfell an area of forest then you remove ALL of the habitats available in that area.  Sure, you might then allow it to regrow, but what you've got is an area of forest that's all the same age and therefore does not provide habitat for the full complement of biodiversity that was there previously.

So, deplete or remove a habitat and you lose all the organisms that depend on it.  Lose habitat and organisms, then your ecosystem loses biodiversity.  It becomes unhealthy and loses it's resilience.

In essence, it is no longer "sustainable" because it no longer able to support future generations at the same level.

So, is it okay to talk about something being "sustainable"?  Sure it is!

Just make sure you really understand what the person or organisation using the word means.  If you don't, by all means question it and find out their motivation in using the word.


  1. I'd started to find the word sustainable really irritates me because it is overused. Now I know that I need to check whether the person really means sustainable (resilient) or profitable!

    1. Often you can tell by the person or organisation saying it what they're likely to mean, but it can be difficult. For example, your local council might use 'Sustainable' when they mean 'it will save us money' and so it could go either way.

      As with anything, question them! :)