Terrestrial ecosystems carbon and water cycles are tightly coupled through photosynthesis and evapotranspiration processes. The ratios of carbon stored to carbon uptake and water loss to carbon gain are key ecophysiological indicators essential to assess the magnitude and response of the terrestrial plant to the changing climate. Here, we use estimates from 10 terrestrial ecosystem models to quantify the impacts of climate, atmospheric CO2 concentration, and nitrogen (N) deposition on water use efficiency (WUE), and carbon use efficiency (CUE). We find that across models, WUE increases over the 20th Century particularly due to CO2 fertilization and N deposition and compares favorably to experimental studies. Also, the results show a decrease in WUE with climate for the last 3 decades, in contrasts with up-scaled flux observations that demonstrate a constant WUE. Modeled WUE responds minimally to climate with modeled CUE exhibiting no clear trend across space and time. The divergence between simulated and observationally-constrained WUE and CUE is driven by modeled NPP and autotrophic respiration, nitrogen cycle, carbon allocation, and soil moisture dynamics in current ecosystem models. We suggest that carbon-modeling community needs to reexamine stomatal conductance schemes and the soil-vegetation interactions for more robust modeling of carbon and water cycles.
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机译:分离的核酸(多核苷酸),反义寡核苷酸,抑制或减少编码CO2SEN蛋白的消息和/或CO2SEN蛋白或植物多聚核苷酸和多肽多糖的植物植株的表达的方法植物保护细胞,植物细胞,植物片,植物组织或植物,植物的一部分的碳吸收量和碳排量的负,正调节及增加,碳保护层和水流以及CO 2 / CO 2交换水交换或损失水开放植物,关闭植物的气孔,部分植物,器官,植物片或植物细胞,以增强或优化植物,植物片,器官,植物,植物的一部分上的生物量积累,植物,种子或植物细胞中的植物细胞或种子,板温度的降低和蒸腾强度的提高,降低了T型保护细胞中的效率降低和碳含量