Trees: evolving perceptions


A journey beginning with concepts as forests as an exploitable resource to realization of their role in saving the planet

By Chris Johansen, GI Co-editor

Along with many of the environmentally concerned I breathed a sigh of relief in September when the WA Government announced an end to native forest logging, even if some loose ends remain (discussed later). This event induced me to recall my own history vis-à-vis trees. Ancestrally and in my early years I could be described as an accomplice to WA forest destruction, my only excuse being that as a child (<12 years old) my terms of reference were rather limited.

An accomplice to arborcide

When very young my aunt (mother’s sister) used to tell me stories about my grandfather trying to establish a wheat farm near Merredin in the late 1920s-early 30s. She was enthralled by the two teams of draft horses dragging a huge chain between them to knock down the bushland. A few years later she noticed that salinity was encroaching in those cleared areas. However, all of this effort came to nothing as my grandfather was forced to abandon the enterprise in the 30s due to recurring drought, rising salts and the global economic depression.

Also when very young (<6) my father would take me with him into the Perth Hills where he would wander through state forest looking for bow pieces for boats – he was a boat builder. On finding a suitably curved large branch or trunk he and his staff would take to it with a huge cross-cut saw.

During the early 50s a school friend used to regularly take me to his family’s sheep farm south of Kojonup. Some of the paddocks were populated by huge ghostly grey skeletons of dead trees, that had earlier been ring-barked. Obviously once a forest of large eucalypts. One of my then most enjoyable experiences during winter visits was setting fire to these dead giants, to clear the paddock. The intense heat from roaring furnace inside the base of trunks up to 2 m in diameter felt so wonderful on those cold winter nights. On reflection decades later, however, I realized that what I had actually been doing was acting as an undertaker cremating dead bodies – and releasing all of that carbon captured over perhaps centuries back into the atmosphere. And then I also noticed the encroachment of salinity in the lower slopes of the paddocks with those dead trees. This recurring theme of salinity perhaps led me to doing my graduate studies on ion movement and interactions in plants.


My environmental epiphany came at some time during the 60’s no doubt reinforced by my studies in plant sciences and ecology. This is evidenced by one of many sarcastic-type stickers I had pasted above my desk, which read something like – “If it moves shoot it, if it stands up chop it down, if its in the ground dig it up”.

On arrival in Darmstadt, Germany to take up a post-doc in September of 1971, I found accommodation on the outskirts of the city, not far from a forest. It looked absolutely beautiful then with all colours of autumn leaves, from still green, through yellow, to red and brown. I was excited to have my first walk through what appeared to be a genuine native temperate European forest. After proceeding a short distance, however, I began to notice that the trunks of some species appeared to be aligned, and further that each tree had a small nameplate. Thus obviously not a “natural” forest but a plantation planted long ago. Then the realization that virtually all “native” forests of central and southern Europe were knocked down for timber, fuel and agricultural development over the last 2,000 or so years.  

Around the world (in 18,000 days or so)

My subsequent career in agricultural R&D took me to many countries across Asia (mainly), Africa and the Middle East. The main challenge was trying to improve crop and pasture yields on degraded soils. Part of the job was trying to understand how those soils came to be that way in the first place. In most circumstances such soils were once heavily forested, to the extent of dense jungles in the tropics. But, with ever burgeoning human populations over recent centuries most of those forests had been cleared, or at least largely degraded from their original form. In Bangladesh for example, once covered by dense jungle, there are now few trees, subsequently planted by humans. British colonists recorded that on clearing the jungle for agriculture the resultant soils were dark brown and friable, choc-a-bloc with organic matter, and crops thrived. However, in that tropical climate, with cultivation the soils quickly turned to a light grey, with levels of organic matter of the order found in light soils of the WA wheatbelt. The main challenge for projects I was in was how to raise soil organic matter levels from their miserably low levels.

Although never seeming to have much spare time, I did try to visit naturally forested areas in the various countries I worked in, to understand how the ecology and soils had changed. Largely an unsuccessful endeavour as, like in Europe, there were few reserves of anything resembling native forest left.

A project in 1983-4 required me to regularly travel to the mountainous region of south-western China. These mountains were in the process of being rapidly denuded of their native forests, with eroding mountain soil piling up in farmers’ fields in the valleys below – I was dumbstruck. On the mountain roads I travelled there were continuous convoys of trucks carry logs down from the mountains. The drivers of these trucks used their brakes, rather than gears, to slow their speed around hairpin curves. I had so many close calls that I thought that I had better find another job. Didn’t want to end my days under a pile of logs at the bottom of a Chinese mountain.

And this horrific scale of deforestation continues around the world to this day, a case in point being the Amazon. It was until a few years back considered a carbon sink, but now it is a carbon source – with the scale of logging and burning promoted by Brazil’s devoutly neoliberal president.

Back to my roots

So, having witnessed first-hand how humans have decimated the vast carbon sink of the planet’s natural vegetation, and on top of that poured ever increasing amounts of fossil carbon into the atmosphere, it was such a relief to learn that a small band of activists, namely the WA Forest Alliance (WAFA), had managed to convince a government to ban native forest logging within its jurisdiction. WA is the first state in Australia to implement such a ban, and there are few jurisdictions in the world that I can think of that have such bans, particularly in the tropics. Not just historic for Australia but globally historic.

However, as Jess Beckerling and colleagues in WAFA point out, this announcement is not clear cut (excuse the term). There appear to be exemptions for mining, considering some remaining jarrah and karri forests stand over bauxite and other mineral deposits. It is unclear where the border between a native and degraded forest lies, and what will happen in those degraded areas. Continued “thinning” would be permitted in native forests areas, putatively for forest maintenance, but it is unclear as to what this implies. I’m not sure that optimum methods of understory management to minimize fire damage and generally preserve ecosystem integrity have yet been worked out. And, since being overridden since colonization, I’m also not sure that the cultural aspects attributed by First Nations traditional owners will be restored – and that they will be given the chance to show us how we should really be living with nature.

My current big beef

Although forever in awe of the above and below ground biodiversity in any forest, I now view forests through the lens of climate change. On the one hand they are increasingly threatened by the effects of climate change (e.g. wildfires, drought, etc.) and on the other hand our only real hope of substantially drawing down atmospheric carbon dioxide (along with other forms of perennial land and marine vegetation). Please forget about human attempts at carbon capture and storage (CCS) – technically too difficult and way too uneconomic.

The use of offsets has been touted as the ideal means of countering ever-rising atmospheric carbon dioxide levels, particularly by Australian conservative federal governments over the last eight years. This involves the creation of carbon credits through tree planting, or promises not to cut down existing trees, to offset ongoing greenhouse gas (GHG) emissions mainly from fossil fuel burning. However, in reality offsets are used as an excuse to continue business as usual GHG emissions.

Basically, the calculation of how much carbon that would be sequestered by planting trees after a given growth period, e.g. 20 years, is equated with a given amount of current GHG emissions. Such calculations are highly dubious. Until the trees reach their designated maturity the carbon sequestered remains in debt to the carbon emitted at the beginning of the process. And if the tree planting is a plantation, when it is cut down for timber much of the carbon sequestered would be lost from the sawmill debris and the newly exposed litter and soil – a net gain for the atmosphere.

But the biggest problem is how to calculate how much carbon will be sequestered by a given planting after a given growth period. Those calculations that I have seen are based on the most courageous of heroic assumptions. Historical records of tree growth rates are extrapolated into the future, a future where the climate is changing. We are already seeing the unprecedented effects of wildfires, extended drought and raised temperatures damaging existing forests. And a changing climate raises the probability of exacerbating pest and disease effects on growing trees. Further, changes in government policy over time could result in removal of the trees within their designated growth period.

Although carbon accumulation over time in above-ground parts of trees can be reasonably calculated ever more heroic assumptions are made about underground sequestration. It has been part of my work over the last 50 years or so to quantify root systems and soil carbon in crops and pastures. Here we only go down to a maximum of one meter or so and I can confirm it ain’t easy to get a representative estimate of roots and soil carbon under crops and pastures. I would not contemplate even trying to do that for trees, whose roots can go downwards and laterally for many meters, and quite variably depending on soil type and water and nutrient regimes, among other factors.

Creating offsets for promises not to cut down trees, as allowed under Australia’s Emissions Reduction Fund, gets even deeper into the world of fantasy. How do you know the landholder was not going to cut down those trees any time soon in any case? This concept appears to have developed from a UN initiative to pay resource poor farmers in developing countries for refraining from deforestation but has been seized upon as a further climate rort by Australian and other governments.

I could go on but in summary, in Australia and more widely, forestry offsets are largely used to justify ongoing emission of GHGs. And their implementation is highly fraught, and an affront to anyone who knows anything about plant physiology and soil carbon. However, I am of course not averse to planting trees and other forms of perennial vegetation as quickly as we can manage, but this should be considered as a separate sequestration exercise rather than used as an excuse for continued and increasing emissions of GHGs. There are no other options but to reduce direct greenhouse gas emissions as a matter of urgency.


When ecocide legislation comes into force, when Greens come into government, I realize that I could be hauled before the courts as an accomplice to historical ecocide. Whether I actually last that long is an extremely moot question. It is much more likely that in the shorter term I will be hauled before courts for absolutely pooh-poohing on government offset programs.

Header photo: Forest near Pemberton, WA, July 2011. Credit: fctdolas, Wikimedia Commons

[Opinions expressed are those of the author and not official policy of Greens WA]