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Summary• The predictive capacity of two simulation models with different degrees of complexity for the calculation of assimilate production, was tested at different time scales, using a data set of wheat grown in an open-top-chamber experiment at two CO 2 concentrations.• Observed values of net canopy assimilation (Pn) were obtained from wheat plants grown at ambient (410 µ mol mol − 1 ) and elevated (680 µ mol mol − 1 ) CO 2 mole fractions. Pn was simulated by using either simple multiple regression equations (AFRCWHEAT2) or by highly detailed calculations of leaf energy balances and the coupling of photosynthesis with stomatal conductance ( LINTULCC2).• Irrespective of the developmental stage of the crop or variation in weather, the models accurately simulated canopy assimilation and growth. We conclude that the response of aboveground-biomass production to elevated CO 2 concentrations was explained primarily by the effects of CO 2 on radiation-use efficiency and assimilate production.• The models explained satisfactorily the daily course of Pn, its integrated daily totals, and the seasonally produced aboveground biomass, both at ambient and elevated CO 2 concentrations. Specific problems in the simulations were identified and discussed.

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Livestock production is a very relevant source of income and agricultural greenhouse gas (GHG) emissions in Colombia,

The International Center for Tropical Agriculture (CIAT) believes that open access contributes to its mission of reducing hunger and poverty, and improving human nutrition in the tropics through research aimed at increasing the eco-efficiency of agriculture. CIAT is committed to creating and sharing knowledge and information openly and globally. We do this through collaborative research as well as through the open sharing of our data, tools, and publications.

To promote the adoption of more sustainable cattle production systems in Colombia (mainly silvopastoral systems with improved forages), some sector stakeholders have proposed the development of differentiated, higher value beef products. However, there have been no rigorous estimations of local market potential and consumer preferences for these hypothetical products yet. On the other hand, while there are clear efforts concerning the environmental impacts of cattle production, its animal welfare implications have taken a secondary place. This research attempts to evaluate the consumer's response to both the environmental and animal welfare aspects of more sustainable food systems by (i) determining the characteristics of a consumer segment for sustainably produced beef using contingent valuation methods and (ii) estimating the marginal willingness to pay (MWTP) for animal welfare compliance and the environmental benefits derived from sustainable intensification within the identified consumer segment, employing a Discrete Choice Experiment (DCE). In addition, the study estimates the effect of information on consumer's MWTP for environmentally friendlier beef. Results show that consumers within the identified segment are willing to pay on average 40.2% more for beef certified with both animal welfare and eco-friendly standards, with an increase of nearly 10% after being provided with information of the sector's environmental impacts. These findings support some of the current climate change mitigation strategies in the national cattle industry while highlighting relevant opportunities and trade-offs in the context of a developing country.

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