Auburn professors comment on the Amazon fires and effects of deforestation

Auburn University School of Forestry and Wildlife professors Christopher Lepczyk and Hanqin Tian comment on the Amazon fires and effects of deforestation.

Dr. Christopher Lepczyk, professor of wildlife biology and conservation:

What do you believe will be the long-lasting effects?

The long lasting effects of these fires, and previous fires, can be state change in the ecosystem, meaning that it shifts to a new set of conditions and makes restoration very difficult. Most Amazonian soils are very shallow and recovering forests in these locations following fires is very difficult, particularly without concerted restoration efforts. With regard to the state change situation, a number of locations in the Amazon have moved to having fire now occurring regularly in locations that did not and should not have fire (an analogy to the Southeast or the prairies of the midcontinent is where fire is removed and the forest or grassland system completely changes).

What should people know about deforestation?

People need to understand that many of the drivers of deforestation are due to policies that allow/promote farming in unsustainable manners or locations (e.g., growing cattle is exceptionally destructive in the Amazon, but cheap beef prices can promote its persistence), basic economics and a continually growing human population that also has a growing demand for material needs/wealth (e.g., the growing human population is also eating more meat, which is creating greater demand for livestock).

How is fire used in forest management? How do wildfires differ?

In the Amazon, fire is being used to remove forests. It is not forest management. Where fire should occur is in ecosystems that are adapted to fire. One misunderstanding at present is that there are forested locations that had fires suppressed for decades that now have so much excess fuel loads that even in the absence of climate change we would have fires that are larger, longer lasting and hotter, than they were historically. Thus, wildfires do occur in many types of forest and grassland ecosystems around the world naturally due to lightning strikes.

How can a fire in a remote area like the Amazon be fought?

Remote firefighting is challenging in any ecosystem. However, in the Amazon one the main issues is enforcement. The lack of on the ground personnel to stop fire ignition is definitely one of the big issues.

Hanqin Tian, the Solon and Martha Dixon Professor and director of Auburn’s International Center for Climate and Global Change Research:

Are Amazon fires occurring more frequently?

The fire occurrence in the dry season of Amazon basin is not new, but becoming more and more frequent in recent years. This might be associated with more frequent El Nino events, which leads to extreme drought in the Amazon basin. In addition, human activities such as deforestation for farming, e.g. soybean and livestock production, create high probability for fire occurrence.

What are the effects of drought and deforestation?

Amazon fires are closely linked with drought and deforestation, which releases large amount of greenhouse gases into the atmosphere and warms the climate. More than half of global tropical rainforests are distributed in Amazonia, playing an important role in global carbon budget and the climate system and explaining about two third of interannual variation in global net primary productivity.

Studies have documented more frequent fire occurrence and higher tree mortality during and after Amazon droughts. For example, the extreme drought of 2015-2016 resulted in higher tree mortality and more fire occurrence, contributing to larger carbon emissions. Higher temperature is another important feature in Amazon drought events. The combined effect of higher temperature and soil water deficit may have led to decrease in ecosystem production and increase in ecosystem respiration.

Drought and fire effects on forest production could persist for several years during recovery processes, which could prevent full recovery of forest functional status and lead to forest degradation and changes in forest species. Future El Nino-Southern Oscillation (ENSO)‐driven extreme climate events, such as Amazon droughts, were projected to be more frequent. If the frequent droughts become a new normal, Amazon forest composition and regional carbon sequestration would be fundamentally altered, which thereby affect global carbon cycling and accelerate climate change.