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

“LTER交叉站点2000：北极和亚北极冻土带气候和营养循环之间的相互作用”拟议的项目将继续由PI和合作者进行的北极生态系统科学的悠久历史。高纬度生态系统的气候强烈限制了氮和磷等基本元素的输入和循环。本研究的主要目的是：1)提高对气候-营养相互作用变异性的原因和后果的理解，以及对北极和亚北极冻土带生态系统中氮和磷的可用性和植物吸收的理解；2)应用这一理解，更好地开发对气候变化响应的大面积、长期预测。这项研究将比较两个地点的生态系统：瑞典的阿比斯库和阿拉斯加的图里克湖。拟议的工作包括：两个讲习班，侧重于各研究所的比较；土壤氮磷周转、植物微生物相互作用和氨基酸吸收的田间研究；初级生产、生物量积累和有机质周转的建模。该项目的新实验部分包括对北极植被吸收有机氮的重要性进行更深入的研究，并将许多正在进行的测量扩展到生长季节的“尾部”，在此期间有重要的迹象，但以前未被重视的生物活动。

" 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.