%0 Journal Article
%T How sensitive are estimates of carbon fixation in agricultural models to input data?
%A Markus Tum
%A Franziska Strauss
%A Ian McCallum
%A Kurt G¨ąnther
%A Erwin Schmid
%J Carbon Balance and Management
%D 2012
%I BioMed Central
%R 10.1186/1750-0680-7-3
%X For our case study analysis we selected two different process based models: the Environmental Policy Integrated Climate (EPIC) and the Biosphere Energy Transfer Hydrology (BETHY/DLR) model. Both process models show a congruent pattern to changes in input data. The annual variability of NPP reaches 36% for BETHY/DLR and 39% for EPIC when changing major input datasets. However, EPIC is less sensitive to meteorological input data than BETHY/DLR. The ECMWF maximum temperatures show a systematic pattern. Temperatures above 20ˇăC are overestimated, whereas temperatures below 20ˇăC are underestimated, resulting in an overall underestimation of NPP in both models. Besides, BETHY/DLR is sensitive to the choice and accuracy of the land cover product.This study shows that the impact of input data uncertainty on modelling results need to be assessed: whenever the models are applied under new conditions, local data should be used for both input and result comparison.Modelling the net carbon uptake by vegetation (Net Primary Productivity, NPP) and estimating the yields of agricultural plants have become important tools to study the mechanisms of carbon exchange between the atmosphere and vegetation, as well as issues of food security. Different approaches are currently tracked which can be grouped to their approaches how photosynthesis is modelled.Models describing the chemical, physical and plant physiological processes of plant development and the interaction of plants with the atmosphere can be applied to simulate the rate of carbon dioxide uptake of the plant through photosynthesis (called Gross Primary Productivity, GPP). These models follow the concept of [1] and [2] to simulate the process of photosynthesis. Moreover, carbon uptake of well-watered and fertilized annual plants is linearly related to the amount of absorbed Photosynthetically Active Radiation (PAR), which can be derived from satellite data (i.e. the fraction of PAR which is absorbed by the canopy; cp. [3] or ca
%K agricultural models
%K net primary productivity
%K EPIC
%K BETHY/DLR
%K land cover
%K weather
%U http://www.cbmjournal.com/content/7/1/3