Modelling of Climate Change and Carbon Storage on North of Portugal: Application of Forest-BGC Model

The main mixed forest species in Portugal are Pinus pinaster Aiton and Quercus pyrenaica Willd. Forests are an important carbon stock in a global scale. Portugal has about 3 million of hectares of forest (30 % of the territory) so it is essential to understand the function of these ecosystems and especially how the water and nutrients cycles work in order to estimate the carbon sequestration and ecosystems productivity during climate changes. Ecophysiological models are often used to make scenarios of future carbon dynamics under different conditions, to monitor the ecosystems and to estimate variables such as net primary production (NPP). Net primary production (NPP) is an important variable that allows forestry ecosystems fixation of atmospheric Carbon. The importance of monitoring the sequestered carbon is related to the binding commitments established by the Kyoto Protocol. There are ecophysiologic models, as Forest-BGC that allow for estimating NPP. In a first stage, this study aims to analyze the climate evolution at the Vila Real administrative district during the last decades. In a next stage these tendencies will be used to infer the impact of these change scenarios on the net primary production of the forest ecosystems from this study area. For a parameterization and validation of the Forest-BGC, this study was carried on based on 500m2 sampling plots from the National Forest Inventory 2006, and are located in several municipalities of the North of Portugal. In order to quantify biomass dynamics, we have selected 46 sampling plots (19 from Pinus pinaster stands, 17 from Quercus pyrenaica and 10 from mixed Quercus pyrenaica with Pinus pinaster). This analysis of selected species found that, while for the crown and root NPP showed in general no significant differences, the same is not true for the trunk. Thus, in case of the trunk's NPP, a temperature increase leads to an increase in the binding capacity of the stand. From the studied species, Pinus pinaster shows higher values of NPP, therefore being the species laying larger amount of carbon. Adaptation strategies for climate change impacts will can be proposed based on these research results.