13 May 2014
The study, published in the Journal of Geophysical Research: Biogeosciences provides a comprehensive climate impact assessment for the forests of Bolivia, for the first time providing an accurate assessment of forest carbon cycling in the country’s diverse forests.
Christian Seiler, the Wageningen University researcher who led the study, recently completed his PhD under the supervision of IIASA Director General and CEO Prof. Dr. Pavel Kabat. Seiler says, “Our study serves as a baseline for assessing the potential impacts of climate change for tropical forests in Bolivia.”
The way that carbon cycles through forests, particularly in tropical regions, is one of the key uncertainties in global climate projections. Forests take up carbon dioxide from the air as they grow, sequestering it in their trunks, branches and leaves. But changes in climate may cause tropical forests to die back, releasing potentially large amounts of carbon back into the atmosphere. On a global scale carbon cycle feedback plays a huge role in how much additional carbon dioxide remains in the atmosphere, adding to global warming.
While some global climate models include forests as one of the major carbon sinks and sources, they are broad and general, and do not provide accurate representations of forest dynamics on a regional level for Bolivia.
To study probabilities and mechanisms of climate-change-induced forest loss, Seiler and colleagues implemented a regionally calibrated vegetation model explicitly for Bolivia. The model includes photosynthesis, respiration, as well as competition of plants for light and water, all factors that influence carbon uptake and storage. Then they compared the results to field measurements and satellite images.
The researchers focused on Bolivia in part because the country includes multiple forest types. Seiler says, “Bolivia is located at the southern fringe of the Amazon with evergreen wet forests in the north, and deciduous dry forests in the south. The country’s geography allowed us to study carbon dynamics along environmental gradients.”
In addition, Bolivia has two large-scale carbon offset projects, which made the country an interesting subject for research related to forest preservation as a climate change mitigation effort. IIASA researchers support such efforts through the Reducing Emissions from Deforestation and Forest Degradation plus forest conservation, sustainable management of forests and enhancement of forest carbon stocks (REDD+) Policy Assessment Center (REDD-PAC), and the new Tropical Flagship Initiative, an integrative research program aimed at tackling tropical deforestation through policy assessment and capacity building.
Seiler says, “Previous studies merely focus at the Amazon as a whole, without considering spatial transitions between different forest types. We identified a number of parameters which were essential for properly simulating the competition between evergreen and deciduous tropical trees, as well as the total amounts of carbon stored in the vegetation. We were surprised about the model's sensitivity to these parameters.”
Seiler, et. al. (2014). Modeling forest dynamics along climate gradients in Bolivia. Journal of Geophysical Research: Biogeosciences. DOI: 10.1002/2013JG002509
The South American continent as seen from space with Bolivia in the center, and the Amazon basin in the north. Blue dots are meteorological stations used to drive the model. Red dots denote locations of biomass measurements used to evaluate the model.
Last edited: 13 May 2014
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