Role of optimum plant nutrition in drought management

Not AvailableGlobal forests are experiencing rising temperatures and more severe droughts, with consistently dire forecasts for negative future impacts. Current research on the physiological mechanisms underlying drought impacts is focused on the water‐ and carbon‐associated mechanisms. The role of nutrients is notably missing from this research agenda. Here, we investigate what role, if any, forest nutrition plays for survival and recovery of forests during and after drought. High nutrient availability may play a detrimental role in drought survival due to preferential biomass allocation aboveground that (1) predispose plants to hydraulic constraints limiting photosynthesis and promoting hydraulic failure, (2) increases carbon costs during periods of carbon starvation, and (3) promote biotic attack due to low tissue carbon: nitrogen (C : N). When nutrient uptake occurs during drought, high nutrient availability can increase water use efficiency thus minimizing negative feedbacks between carbon and nutrient balance. Nutrients are released after drought ceases, which might promote faster recovery but the temporal dynamics of microbial immobilization and nutrient leaching have a significant impact on nutrient availability. We provide a framework for understanding nutrient impacts on drought survival that allows a more complete analysis of forest ecosystem responses. I. Introduction Research on the physiological mechanisms of drought‐induced mortality has grown significantly in recent years as observations and simulations have increasingly pointed to the growing threat of climate change impacts on forests (reviewed recently in Allen et al., 2015). The logical impacts of drought and warming on plant carbon (C) and water economies have driven research to focus almost exclusively on these factors, with additional emphasis on insects and pathogens (McDowell, 2011; Hartmann et al., 2013; Anderegg et al., 2015 and many others). Our understanding of the mechanisms of drought‐induced impairment of plant functioning and subsequent mortality, as well as tree and ecosystem recovery after mortality events, has grown enormously via this international‐scale effortNot Availabl