Nighttime Warming Will Increase Winter Wheat Yield Through Improving Plant Development and Grain Growth in North China
The letter by Amthor et al. (in this issue) on our paper (Aronson and McNulty, 2009) raised some interesting questions and noted an error in our original text. In Aronson and McNulty (2009), we misstated that anthropogenic-induced global warming would result from increased infrared radiation (IR), when the sentence should have read increased convection and conduction. The authors do not believe that increased greenhouse gas emissions will increase solar radiation output, or significantly increase IR to the Earth’s surface. We thank Amthor et al. for that correction. The assertion that IR lamps mimic the action of global warming due to increased longwave radiation on the land surface was cited from Harte et al. (1995). However there have been advances in the study of global warming heat transfer, which were not considered. This assertion was erroneously repeated in Aronson and McNulty (2009) and we thank Amthor et al. for this correction as well. In our paper we made recommendations for ecosystem warming study methods based on the literature available on simulated ecosystem warming. Of the active warming methods in the literature, only two have been published on extensively, and therefore lend themselves to review: heat-resistance cables buried in or on the soil surface and IR lamps. Of these, only IR lamps transfer heat to the soil and air above the surface without direct contact of a heating element on the soil. Given that IR lamps do not contact the soil surface directly, and therefore minimize in situ disturbance, we stand by our assessment of these methods. However, any new technologies which can actively heat the soil and surrounding air effectively and better mimic the action by which global warming will warm the soil, would be welcomed by the scientific community.