LTER Cross-Site: Interactions between Climate and Nutrient Cycling in Arctic and Subarctic Tundras

“LTER跨站点2000：北极和亚北极冻土带气候和营养循环之间的相互作用”拟议的项目将延续国际和平研究所及其合作者在北极生态系统科学方面的悠久历史。高纬度生态系统的气候强烈限制了N和P等基本元素的输入和周转。这项研究的广泛目的是：1)提高对气候-养分相互作用以及北极和亚北极冻土带生态系统中N和P的有效性和植物吸收差异的原因和后果的理解；2)应用这种理解来更好地开发对气候变化反应的大面积、长期预测。这项研究将比较两个地点的生态系统：瑞典的阿比斯科和阿拉斯加的图利克湖。拟议的工作包括：两个讲习班，重点是在STESS进行比较；关于土壤中N和P周转、植物微生物相互作用和氨基酸吸收的实地研究；以及初级生产、生物量积累和有机质周转的模拟。该项目新的实验部分包括更深入地研究北极植被吸收有机氮的重要性，并将许多正在进行的测量延伸到生长季的“尾巴”，在此期间有迹象表明重要的、但以前未得到重视的生物活动。

" LTER Cross site 2000: Interactions between climate and nutrient cycling in Arctic and Subarctic tundras"The proposed project would continue a long history of arctic ecosystem science by the PI and collaborators. The climate of high latitude ecosystems strongly limits the inputs and turnover of essential elements like N and P. The broad aims of this research are to: 1) improve understanding of the causes and consequences of variability in climate-nutrient interactions and in the availability and plant uptake of N and P among contrasting arctic and Subarctic tundra ecosystems and 2) to apply this understanding to better develop large-area, long-term predictions of their responses to climate change. The research will compare ecosystems at two sites: Abisko in Sweden and Toolik Lake in Alaska. The proposed work involves: two workshops focused on comparisons at the sties; field research on N and P turnover in soil, plant microbe interactions, and amino acid uptake; and modeling of primary production, biomass accumulation, and organic matter turnover. The new experimental component of the project includes a deeper examination of the importance of organic N uptake by arctic vegetation and extends many ongoing measurements to the "tails" of the growing season during which time there is indication of important, but previously under appreciated biological activity.