Logging sharply increases fire risk for endangered forests

The Mountain Ash forests of southeastern Australia are renowned for supporting the world's tallest flowering plants.  Sadly, clear-cut logging and fierce fires have devastated these once-magnificent forests, with just a tiny fraction of the original old-growth forest remaining.  Now a new study shows that logged forests are far more likely to burn than those that have never been logged.

Razed forests...

Razed forests...

The study, led by Chris Taylor and renowned forest-expert David Lindenmayer, was based on careful statistical analysis of past fire and logging histories.  It found that younger forests -- those logged 7-36 years previously -- were far more likely to suffer intense fires during dry conditions.

Logged forests, they found, had an altered structure and flammable slash in the understory, which made the forests much more vulnerable to intense fires.

The intense fires have a huge impact on native wildlife, particularly the endangered Leadbeater's Possum, which requires mature forest for survival.  Such mega-fires have also killed hundreds of people and destroyed thousands of homes and private properties in southeastern Australia. 

The authors argue that current logging is creating a long-term legacy, making the small patches of surviving old-growth forest much more vulnerable to devastating fires in the future. 

Halting industrial logging, they argue, is the only solution for the endangered Mountain Ash forests.

Indonesia now biggest 'forest killer'

It's a dubious honor: Indonesia is now officially the world's biggest destroyer of forests.  What's more, the pace of forest loss appears to be accelerating.

High price for biodiversity...

High price for biodiversity...

Any way you look at it, Indonesia is a mega-diversity nation for plants and animals.  And virtually nowhere else on Earth has more endangered species, including the tiger, orangutan, clouded leopard, and Sumatran and Javan rhinoceros.

Satellite data reveal that, from 2000 to 2012, Indonesia destroyed its native old-growth forests at a stunning pace, losing over 6 million hectares (15 million acres).  That's an area almost the size of Ireland.

Meanwhile, deforestation in Brazil -- formerly the no. 1 forest feller -- has declined substantially in recent years

Equally alarming is that deforestation appears to be worsening in Indonesia, despite major international initiatives to slow forest loss there.  In 2012, the country cleared 840,000 hectares of its old-growth forests, more than any year in the preceding decade. 

Accelerating deforestation in Indonesia  (from Mongabay)

Accelerating deforestation in Indonesia (from Mongabay)

Brazil, whose forests are much more extensive, lost just 460,000 hectares in 2012.

It's a label no nation should want: Indonesia is now the undisputed global 'leader' in destroying its native forests

The debate about forest conservation

In conservation practice, as in just about everything else, the pendulum of opinion swings back and forth. 

Right now, many ecologists are emphasizing the importance of conserving or rehabilitating forests that have been altered in various ways--such as selectively logged forests or secondary forests that are regenerating on formerly cleared land. 

Still valuable...  tiger footprint in a regenerating forest in Sumatra (photo by William Laurance).

Still valuable...  tiger footprint in a regenerating forest in Sumatra (photo by William Laurance).

One reason for this is that such modified habitats are so prevalent, and sometimes intensely vulnerable, across the planet.  For instance, around 400 million hectares of tropical forest globally is in some kind of logging estate.  Indonesia alone has at least 35 million hectares of selectively logged forest--an area larger than Germany--and much of this logged forest is unprotected and being cleared for agriculture. 

But there are also those who emphasize the values of old-growth forest.  One example is ALERT member Corey Bradshaw, who explains his views in this recent interview on Mongabay.

Bradshaw's views echo an analysis we published in Nature in 2011.  In that study, we found old-growth tropical forests had higher biodiversity-conservation values than all other modified forests or lands.  Nonetheless, native forest that had been selectively logged came in a close second, underscoring the importance of conserving these vulnerable forests.

In the end, no single conservation strategy always wins out.  All forests have value, and in many parts of the world, modified forests are just about all that remains.  That doesn't diminish the vital need to conserve old-growth forests wherever they still survive.

-Bill Laurance