Research Featured in World’s Top Science Journal

Dr. Eben Broadbent (front) and Dr. Angelica Almeyda Zambrano (third from front), with field assistants from the Instituto Boliviano de Investigacion Forestal, carry a ‘pequi-pequi’ boat motor to the river in preparation for travel to one of their forest study sites.

Dr. Eben Broadbent (front) and Dr. Angelica Almeyda Zambrano (third from front), with field assistants from the Instituto Boliviano de Investigacion Forestal, carry a ‘pequi-pequi’ boat motor to the river in preparation for travel to one of their forest study sites.

From the February 2016 Desktop News | Last week’s online edition of Nature, the world’s most highly cited interdisciplinary scientific journal, published research co-authored by Department of Geography professors Drs. Eben Broadbent and Angelica Almeyda Zambrano.

On average, Nature publishes only 8 percent of the 200 or more research papers submitted for publication each week due to rigorous selection criteria, according to the journal. In 2013, only 856 of the 10,952 papers submitted to Nature were published.

Most submissions are declined without being reviewed.

Dr. Angelica Almeyda Zambrano, UA adjunct professor of geography, said getting published in Nature was a well-earned victory for the whole team.

“We’ve never been published in Nature before,” she said.

Broadbent and Almeyda Zambrano’s article, “Biomass Resilience of Neotropical Secondary Forests,” is about the natural rate of recovery of secondary forests in the neotropics of Latin America after deforestation.

A secondary forest is a forest that’s been naturally regrown—without human interference—after an old-growth forest has been cut down. Old-growth forests are original forests of native trees that have been mostly undisturbed by man.

“Globally, an area of rainforest about the size of a U.S. football field is lost every second,” Broadbent said. “Deforestation in Latin American countries is very high, with Brazil having among the highest rates in the world.

“On a global scale, there are half old-growth forests and half secondary forests.”

Most old-growth forests throughout Latin America are cut down so the land can be farmed. But once the soil loses its fertility, farmers abandon the land and move on.

“It loses its fertility, and people let forests regrow in them just like anywhere here in Alabama,” Broadbent said. “After a certain amount of time, they become forests again.”

“The question we asked was, ‘How fast are they becoming forests again?’”

Almeyda Zambrano and Broadbent teamed up with 63 professors representing 45 colleges and universities to answer that question. They explored 45 secondary forest sites across Latin America and measured approximately 170,000 trees.

What they discovered is that the rate of recovery for secondary forests is dependent on four factors—rainfall totals, what the land was used for after an old-growth forest was cut down, climate, and landscape.

“Rainfall came out as being the most significant factor,” Broadbent said. “That’s really what’s going on here.

“Wet forests have a quicker recovery rate, and dry forests typically have a very low regrowth rate.”

Almeyda Zambrano said the paper is the first to be published showing the rate of secondary forest recovery.

The research has wide-ranging impact because secondary forest recovery affects the global carbon cycle, which affects global warming and climate change.

“Globally, forests uptake carbon at different rates,” Almeyda Zambrano said. “Understanding how this rate is distributed is important because the more carbon that is taken up by forests, the less that remains in the atmosphere, and the less that remains to contribute to global warming. These findings have implications which are very relevant to international policy making.”

Almeyda Zambrano and Broadbent spent four months in Bolivia in 2007 collecting the data they contributed to the study. Of the approximate 170,000 trees analyzed in the study, they examined about 8,000 of them.

They also conducted geospatial analyses for the study and created the maps showing regrowth carbon uptake rates featured in the journal.