Why protecting forests means tackling logging, climate change

Recent commentary on forest management has suggested that the effects of climate change on forests outweigh the impacts of logging. These comments miss some key points and ignore the underlying science of forest ecology.

They need to be debunked because they imply we should not be concerned about the impact of logging, when we most definitely should be. Critically, climate change and logging are not independent drivers of forest change and degradation. Nor are they independent in their effects on forest biodiversity.

Logging’s climate impact

First, logging creates significant greenhouse gas emissions which contribute to climate change. For example, logging in Tasmania generates levels of emissions equivalent to 1.1 million motor vehicles annually.

By contrast, forests left intact store far more carbon, and unlogged old-growth forests – full of large, centuries-old trees – store the most of all. Logging releases much of that carbon, while leaving forests standing keeps it locked away.

This is important because tackling climate change depends on both reducing emissions (including by not generating emissions from cutting forests) and by storing more carbon in forests (by ensuring forests grow old by not cutting them down).

Second, while climate change is clearly driving up temperatures, logging is contributing to this warming as well. Empirical studies of forest microclimates have consistently demonstrated that intact old forests maintain the coolest and most thermally stable conditions, with their dense, structurally complex canopies buffering the forest interior against temperature extremes.

This is important for temperature-sensitive species that can otherwise be severely affected by rising temperatures.

The best-buffered microclimatic conditions for endangered animals like the southern greater glider are in old-growth forests, where they are now most likely to be found.

The lowest daytime temperatures for these nocturnal animals are in tree hollows within large old trees – the kinds of trees that are either removed in logging operations or prevented from reaching maturity by repeated logging operations on rotation times of less than 120 years.

The bottom line is that intact forests will be among the most important short- to medium-term refugia for many climate-threatened species.

Multiple stressors, shared solutions

Third, forest ecosystems and the biodiversity that is dependent on them have to deal with not just climate change, or not only logging, but both – and the interactions between them. Wildfire in forests is a classic and increasingly well-documented case of a compounding effect of climate change and logging.

Increasing temperatures driven by climate change have significantly increased the prevalence of high-risk weather. At the same time, logged and regenerated forests are more flammable than intact forests – with elevated fire severity effects lasting for 40–70 years after an area was initially cut.

Our forests and the forest biodiversity that live in them therefore must deal with the multiple stressors of climate change, logging, fire, and the interactions between all three.

Many studies have demonstrated that ecosystems become increasingly vulnerable with an increasing number of stressors. Conversely, an important part of effective conservation is to reduce the number of factors which stress an ecosystem.

We most definitely need to tackle climate change, but this is a monumental long-term challenge because it is a global issue demanding decisive action on the part of many nations, including our own.

Halting logging is a more tractable, near-term action at a regional and state level that will have a demonstrable immediate positive impact on forest integrity and forest biodiversity. This means that halting logging has a high level of what is termed management ’leverage’ in environmental improvement.

In summary, climate undoubtedly affects forests and forest biodiversity, but so too does logging. The real issue is not about whether one is worse than the other.

Rather, it’s the fact that forests must deal with both as well as the interactions between climate and logging. We therefore must tackle both problems, by slowing and eventually reversing climate change and by stopping the logging of native forests.

This column first appeared on Pearls and Irritations and is republished by Global Catholic with permission.