IPY: Autotrophic Respiration in a Changing Arctic Climate: Mechanistic Responses and Ecosystem Consequences

极地地区的环境变化剧烈而迅速。这强调了科学和社会都需要了解气候与极地生态系统的结构和功能（或可持续性）之间的关系。这个项目的目标是对阿拉斯加北极苔原的这些关系进行预测性的理解，阿拉斯加可以说是地球上气候变化最快的地方。该项目是在阿拉斯加进行的一项实地研究，重点关注北极植物的一个独特而重要的方面：北极短暂夏季的恒定日光条件如何抑制植物叶片的呼吸作用，这是通过光合作用过程获得的宝贵碳的主要潜在损失。对南方生态系统植物的生理学研究表明，在光照下，植物的呼吸作用部分受到抑制。然而，目前尚不清楚的是，北极夏季特有的持续日照是如何影响植物呼吸的，以及这如何影响整个植物和生态系统的碳平衡。提出了三个具体问题：(1)在北极野外条件下，恒定光照对叶片呼吸的抑制程度有多大；(2)未来气候变化的预测情景如何影响这种抑制；(3)光对植物呼吸的抑制如何影响整个生态系统的碳平衡？这项研究将利用苔原野外研究站现有的实验，那里的温度和营养都已被控制。这项研究的结果将为北极正在进行的长期生态研究和环境观测能力增加一个新的维度。这个国际研究小组还将在阿拉斯加土著社区的一个公共论坛上提供讲座，让各级学生参与这项研究，并为发展中的科学记者提供一个培训基地。

Environmental change in Polar regions is dramatic and rapid. This emphasizes a need for both science and society to understand the relationships between climate and the structure and functioning (or sustainability) of Polar ecosystems. The goal of this project is to develop predictive understanding of these relationships in the arctic tundra of Alaska, arguably the location on earth where climate change is most rapid. The project is a field study in Alaska that focuses on a unique and important aspect of arctic plants: how the constant daylight conditions of the short arctic summer inhibit the respiration of plant leaves, the main potential loss of precious carbon gained via the process of photosynthesis. Physiological studies of plants from ecosystems further south have revealed that respiration is partially inhibited in the light. However, what is not known is how constant daylight, unique in the arctic summer, influences plant respiration, and then how this affects the carbon balance of whole plants and ecosystems. Three specific questions are posed: (1) How much does constant light inhibit leaf respiration under Arctic field conditions, (2) How might predicted scenarios of future climate change influence such inhibition, and (3) How is the carbon balance of whole ecosystems affected by light inhibition of plant respiration? The study will take advantage of existing experiments at a tundra field research station where both temperature and nutrition have been manipulated.The results from this study will add a new dimension to ongoing long-term ecological research and environmental observing capabilities in the Arctic. The international team of researchers will also provide lectures in a public forum in native Alaskan communities, involve students of all levels in the research, and provide a training ground for developing scientific journalists.