ABSTRACT
Plant responses to rising atmospheric carbon dioxide (CO2) concentrations, together with projected variations in temperature and precipitation will determine future agricultural production. Estimates of the impacts of climate change on agriculture provide essential information to design effective adaptation strategies, and develop sustainable food systems. Here, we review the current experimental evidence and crop models on the effects of elevated CO2 concentrations. Recent concerted efforts have narrowed the uncertainties in CO2-induced crop responses so that climate change impact simulations omitting CO2 can now be eliminated. To address remaining knowledge gaps and uncertainties in estimating the effects of elevated CO2 and climate change on crops, future research should expand experiments on more crop species under a wider range of growing conditions, improve the representation of responses to climate extremes in crop models, and simulate additional crop physiological processes related to nutritional quality.
ABSTRACT
Nature Plants 3, 17102 (2017); published online 17 July 2017; corrected online 27 September 2017.
ABSTRACT
This corrects the article DOI: 10.1038/nplants.2017.102.
ABSTRACT
This corrects the article DOI: 10.1038/nplants.2017.102.
ABSTRACT
Increasing the accuracy of crop productivity estimates is a key element in planning adaptation strategies to ensure global food security under climate change. Process-based crop models are effective means to project climate impact on crop yield, but have large uncertainty in yield simulations. Here, we show that variations in the mathematical functions currently used to simulate temperature responses of physiological processes in 29 wheat models account for >50% of uncertainty in simulated grain yields for mean growing season temperatures from 14 °C to 33 °C. We derived a set of new temperature response functions that when substituted in four wheat models reduced the error in grain yield simulations across seven global sites with different temperature regimes by 19% to 50% (42% average). We anticipate the improved temperature responses to be a key step to improve modelling of crops under rising temperature and climate change, leading to higher skill of crop yield projections.
Subject(s)
Agriculture , Crops, Agricultural/growth & development , Temperature , Computer Simulation , Models, BiologicalABSTRACT
⢠Understanding how trees are affected by a long-term increase in atmospheric CO2 is crucial to understanding the future impact of global climate change. Measurements of photosynthetic characteristics were made in sour orange trees (Citrus aurantium) growing under an enhanced CO2 atmosphere and N-replete soil for 14 yr to determine whether photosynthetic down-regulation had occurred. ⢠Photosynthesis, A : Ci gas exchange relationships and Rubisco activity and content were measured throughout the 14th year of the experiment. The CO2 -induced enhancement ratio of photosynthesis was calculated and compared with estimates of the enhancement of cumulative wood biomass production. ⢠Content of the large subunit of Rubisco was significantly reduced by CO2 enrichment indicating that down-regulation had occurred. A high correlation between the CO2 -induced enhancement of photosynthesis and the enhancement of cumulative wood biomass production suggested that the decline in wood biomass production was closely related to the decline in photosynthesis. ⢠These results indicate that long-term CO2 enrichment can result in photosynthetic down-regulation in leaves of trees, even under nonlimiting N conditions.
