Integrated sap flow systems to evaluate the impact of short-droughts on evapotranspiration and carbon uptake in age-sequence of planted conifer forests

森林在全球碳循环中发挥着不可或缺的作用，它通过光合作用将大气中的二氧化碳(CO2)封存到植被生物量中，并通过植物和土壤呼吸以及生物质分解释放二氧化碳。在过去的几十年里，加拿大和美国的种植园或绿化森林一直是一个巨大的碳(C)汇。然而，最近的研究表明，它们的碳固存能力正受到区域气候变化的影响。气候变暖、冬/夏气温上升和热事件增加了蒸发量，导致更频繁的干旱事件。短期的严重干旱事件可能会大大减少森林的光合作用吸收，特别是在春季和初夏的生长高峰期。森林水文的变化也改变了土壤碳排放，土壤碳排放通过碳循环和水循环进行反馈。

Forests play an integral role in the global carbon cycle by sequestering atmospheric carbon dioxide (CO2) into vegetation biomass through photosynthesis and releasing CO2 through plant and soil respiration and biomass decomposition. Plantation or afforested forests in both Canada and the United States have been a large carbon (C) sink over many of the last decades. However, recent studies indicate that their carbon sequestration capabilities are being affected by changes in regional climate. Climate warming, increasing winter/summer temperatures and heat events have increased evaporation, causing more frequent drought events. Short-term, severe drought events may significantly reduce forest photosynthetic uptake, particularly when they occur during the peak growing periods of spring and early summer. Changes in forest hydrology alters soil carbon emissions as well, which feeds-back on both carbon and water cycles.