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

极地地区的环境变化是剧烈而迅速的。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。该项目的目标是在阿拉斯加的北极苔原上发展对这些关系的预测性理解，可以说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，这是通过光合作用获得的宝贵碳的主要潜在损失。对更南部生态系统的植物进行的生理学研究表明，呼吸作用在光照下受到部分抑制。然而，目前尚不清楚的是，北极夏季独特的持续日光如何影响植物呼吸，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）在北极田间条件下，持续光照对叶片呼吸的抑制程度如何，（2）未来气候变化的预测情景可能如何影响这种抑制，以及（3）整个生态系统的碳平衡如何受到光的影响植物呼吸的抑制？这项研究将利用在一个冻原实地研究站进行的现有实验，在那里对温度和营养进行了操纵，研究结果将为北极地区正在进行的长期生态研究和环境观测能力增添新的内容。国际研究人员团队还将在阿拉斯加土著社区的公共论坛上提供讲座，让各级学生参与研究，并为培养科学记者提供培训场所。

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.