Purchase College Professor Susan Letcher's Innovative Work Featured in Nature

Following the Paris Climate Change Conference, the whole world has been focused on climate change and what can be done to lessen the effects. This week’s issue of Nature features an important article by Lourens Poorter and an international team of researchers including Purchase College professor Susan Letcher, based on their fascinating work in Latin America studying forest ecology in hopes of reducing carbon emissions and increasing carbon uptake.

While many scientists focus on old-growth tropical forests, the important findings show that secondary forests that regrow after nearly complete removal can sequester large amounts of carbon in a short amount of time, therefore providing an affordable and nature-based solution to one of the greatest problems plaguing the earth.

Working with an international team of forest ecologists led by researchers from Wageningen University in the Netherlands, Professor Letcher and her fellow scientists analyzed 1500 forest plots and 45 sites across Latin America to demonstrate that tropical forests grow back rapidly after disturbance, storing large amounts of carbon, and may be able to counterbalance climate change to a greater degree than previously thought.

Lead author Professor Lourens Poorter says, ”Carbon uptake is surprisingly fast in these young forests that regrow on abandoned pastures or abandoned agricultural fields. After 20 years, these forests have recovered already 122 tons of biomass per hectare (2.5 acres). This corresponds to an uptake of 3.05 ton carbon per hectare per year, which is 11 times the uptake rate of old-growth forests.”

To put this into perspective, it takes about 1 metric ton of carbon emissions to meet the monthly energy requirements for the average U.S. household. Protecting tropical forests and allowing them to regrow could provide a powerful offset for emissions.

The research team believes their findings will be a vital tool for regional and national policy makers who can use this information to identify areas that should be conserved. Policy makers can identify areas that have a slow recovery and are more difficult to restore, or to identify areas with fast recovery, where forest regrowth or reforestation has a high chance of success.

An environmental scientist and terrestrial ecologist, Professor Letcher studies forest recovery in Costa Rica, where she has conducted fieldwork since 2003. She said, “It’s remarkable how fast tropical forests can recover, given the opportunity,” she remarks. “Where I grew up in Maine, a 15-year-old forest is basically a thicket of trees as big around as my arm. In some of these tropical forests after 15 years, there are trees too big for me to hug.” She emphasizes the hopeful nature of these results: “The natural world is incredibly resilient. If was can harness the power of that resilience, we can mitigate some of the harm that human activity imposes on the world and its climate system.”