A study finds that changes in tropical forest structure and function at forest edges, which have proliferated as forests have fragmented, diminish forests' carbon storage ability. Tropical forests are the largest terrestrial component of the carbon budget. However, land conversion and forest fragmentation have brought 20% of tropical forests within 100 meters of a nonforest boundary. The effects of such fragmentation on carbon storage are unclear, but observations suggest that tropical forests are losing carbon storage potential over time and may have become carbon sources instead of sinks. Elsa Ordway and Greg Asner used airborne laser scanning and imaging spectroscopy taken along boundaries between forests and oil palm plantations in Malaysian Borneo to quantify forest canopy structure and function. Along these forest edges, the authors found aboveground carbon storage declines of 22% up to 100 meters from the boundary. Boundary areas also exhibited decreased canopy height and leaf mass, and boundary age amplified carbon storage declines. According to the authors, the results demonstrate the need to consider ecosystem sensitivities to neighboring land management and highlight the long-term vulnerability of tropical forests' carbon storage capacity when they neighbor agricultural plantations.
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Article #19-14420: "Carbon declines along tropical forest edges correspond to heterogeneous effects on canopy structure and function," by Elsa M. Ordway and Gregory P. Asner.
MEDIA CONTACT: Gregory P. Asner, Arizona State University, Tempe, AZ; tel: 650-380-2828; e-mail: gregasner@asu.edu
Proceedings of the National Academy of Sciences