Impacts of climate change, extreme weather events and management activities on managed conifer and deciduous forests

森林为社会提供了众多的环境、生态、社会和经济效益。加拿大东部和美国的很大一部分森林是不同树龄的人工林或管理林，它们吸收大气二氧化碳(CO2)以抵消部分化石燃料的排放。在过去的几十年里，由于过去的收获、农业废弃和植树造林的恢复，这些森林一直是一个巨大的碳(C)汇。然而，最近的研究表明，它们正受到区域气候变化和干旱、洪水和热浪等极端天气事件的影响。气候变暖加速了水文循环。森林水文循环的变化改变了森林的生长和土壤和植物的养分循环，从而反馈了碳、水循环和区域气候。迫切需要确定环境变化对森林生态系统中碳、水和养分循环的影响，特别是在不同年龄的人工林和管理林中，以充分了解它们的功能和对未来气候变化和极端天气事件的反应。我们已经建立了四个通量塔站点，包括三个针叶树龄序列(75年、40年、12年)造林林和一个管理落叶林(&gt；80年)林。所有四个林分都位于朗点地区自然保育管理局分水岭内。

Forests provide numerous environmental, ecological, social and economic benefits to society. A large portion of forests in eastern Canada and US are plantation or managed forests of different ages that absorb atmospheric carbon dioxide (CO2) to offset some of the fossil fuel emissions. These forests have been a large carbon (C) sink over the last many decades due to recovery from past harvesting, agricultural abandonment and afforestation. However, recent studies indicate that they are being affected by changes in regional climate and extreme weather events such as drought, floods and heat waves. Climate warming has accelerated the hydrological cycle. Changes in forest hydrological cycle alter its growth and soil and plant nutrient cycling, which feeds-back on both carbon and water cycles and regional climate. There is an urgent need to determine the impact of environmental changes on carbon, water and nutrient cycling in forest ecosystems --in particular in different-age plantation and managed stands to fully understand their functioning and response to future climate change and extreme weather events. We have established four flux tower sites, including three conifer age-sequence (75, 40, 12 year old) afforested stands and a managed deciduous (>80 year old) stand. All four stands are located in Long Point Region Conservation Authority watershed.