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

极地地区的环境变化是戏剧性和快速的。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。这个项目的目标是对阿拉斯加北极冻土带的这些关系进行预测性的理解，那里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，重点关注北极植物独特而重要的一个方面：北极短短的夏季持续的日光条件如何抑制植物叶片的呼吸，即通过光合作用过程获得的宝贵碳的主要潜在损失。对更靠南的生态系统中的植物进行的生理学研究表明，呼吸作用在光照下部分受到抑制。然而，在北极夏季独一无二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，目前还不得而知。提出了三个具体的问题：(1)在北极田野条件下，持续的光照对叶片呼吸有多大的抑制作用；(2)未来气候变化的预测情景可能如何影响这种抑制；(3)光抑制植物呼吸对整个生态系统的碳平衡有何影响？这项研究将利用冻土带野外考察站的现有实验，那里的温度和营养都受到了控制。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。国际研究团队还将在阿拉斯加原住民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.