Insight
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Publications in Brazilian Amazon by NOMIS researchers

Logged and structurally degraded tropical forests are fast becoming one of the most prevalent land-use types throughout the tropics and are routinely assumed to be a net carbon sink because they experience rapid rates of tree regrowth. Yet this assumption is based on forest biomass inventories that record carbon stock recovery but fail to account for the simultaneous losses of carbon from soil and necromass. Here, we used forest plots and an eddy covariance tower to quantify and partition net ecosystem CO2 exchange in Malaysian Borneo, a region that is a hot spot for deforestation and forest degradation. Our data represent the complete carbon budget for tropical forests measured throughout a logging event and subsequent recovery and found that they constitute a substantial and persistent net carbon source. Consistent with existing literature, our study showed a significantly greater woody biomass gain across moderately and heavily logged forests compared with unlogged forests, but this was counteracted by much larger carbon losses from soil organic matter and deadwood in logged forests. We estimate an average carbon source of 1.75 ± 0.94 Mg C ha−1 yr−1 within moderately logged plots and 5.23 ± 1.23 Mg C ha−1 yr−1 in unsustainably logged and severely degraded plots, with emissions continuing at these rates for at least one-decade post-logging. Our data directly contradict the default assumption that recovering logged and degraded tropical forests are net carbon sinks, implying the amount of carbon being sequestered across the world’s tropical forests may be considerably lower than currently estimated. Copyright © 2023 the Author(s).

Research field(s)
Natural Sciences, Biology, Ecology

NOMIS Researcher(s)

July 1, 2020

Illegal activity, such as deforestation for illicit crops for cocaine production, has been inferred as a cause of land change. Nonetheless, illicit activity is often overlooked or difficult to incorporate into causal inference models of land change. Evidence continues to build that narcotrafficking plays an important, yet often unreported, role in forest loss. This study presents a novel strategy to meet the challenge of estimating the causal effect of illicit activity in land change using consolidated news media reports to estimate the relationship between drug trafficking and accelerated forest loss in Central America. Drug trafficking organizations engage in illegal land transactions, money laundering, and territorial control that can manifest as forest conversion to agriculture or pasture land uses. Longitudinal data on 50 sub-national units over a period of 16 years (2001-2016) are used in fixed effects regressions to estimate the role of narcotrafficking in forest loss. Two narcotrafficking activity proxies were developed as explanatory variables of forest loss: i) an “official” proxy from drug seizures data within 14 sub-national units; and, ii) an “unofficial” proxy developed from georeferenced news media accounts of narcotrafficking events. The effect of narcotrafficking was systematically compared to the other well-known causes of forest loss, such as rural population growth and other conventional drivers. Both proxies indicate narcotrafficking is a statistically significant (p<0.01) contributor to forest loss in the region, particularly in Nicaragua (p<0.05, official proxy), Honduras (p<0.05, media proxy), and Guatemala (p<0.05, media proxy). Narcotrafficking variables explain an additional 5% (media proxy) and 9% (official proxy) of variance of forest loss not captured by conventional models. This study showed the ability of news media data to capture the signal of illicit activity in land use changes such as forest loss. The methods employed here could be used to estimate the causal effect of illicit activities in other land and environmental systems. Our results suggest that current drug policy, which concentrates drug trafficking in remote areas of very high cultural and environmental value, has helped to accelerate the loss of Central America's remaining forests.

Research field(s)
Natural Sciences, Earth & Environmental Sciences, Environmental Sciences

NOMIS Researcher(s)

July 1, 2020

This research is motivated by the compelling finding that the illicit cocaine trade is responsible for extensive patterns of deforestation in Central America. This pattern is most pronounced in the region’s large protected areas. We wanted to know how cocaine trafficking affects conservation governance in Central America’s protected areas, and whether deforestation is a result of impacts on governance. To answer this question, we interviewed conservation stakeholders from key institutions at various levels in three drug-trafficking hotspots: Peten, Guatemala, Northeastern Honduras, and the Osa Peninsula in Costa Rica. We found that, in order to establish and maintain drug transit operations, drug-trafficking organizations compete with and undermine conservation governance actors and institutions. Drug trafficking impacts conservation governance in three ways: 1) it undermines long standing conservation coalitions; 2) it fuels booms in extractive activities inside protected lands; and 3) it erodes the territorial control that conservation institutions exert, exploiting strict “fortress” conservation governance models. Participatory governance models that provide locals with strong expectations of land tenure and/or institutional support for local decision-making may offer resistance to the impacts on governance institutions that we documented.

Research field(s)
Natural Sciences, Earth & Environmental Sciences, Environmental Sciences