Soil carbon stabilization along productivity gradients in interior Alaska: Summer 2003

Boreal forests in a warmer future climate are likely to exhibit altered productivity levels, tightened fire return intervals, and increased decomposition rates to varying degrees across the landscape. This research focuses on mechanisms of soil C stabilization in P. mariana systems along gradients in stand productivity. Charred material in the soil will be quantified to understand the lasting effect of fire on the stabilization of soil C. The interaction between temperature and productivity in relation to the stabilization of soil C will be investigated by monitoring climate and soil temperatures along the productivity gradients and through laboratory incubations of soil. Research questions are addressed in three main areas of inquiry: 1) how the interaction between stand production and landscape position effect the stabilization of C throughout the soil profile, 2) how the contribution of burn residues to total C accumulation varies across the landscape, and 3) the relationship between aboveground productivity and burn residues across the landscape. The overall goal is to apply an understanding of the biophysical controls on C storage in the boreal forest to the landscape level.

在未来气候变暖的背景下，北方针叶林（Boreal Forest）的生产力水平大概率会发生改变，火灾回归周期将缩短，且土壤有机质分解速率会在不同景观区域出现不同程度的升高。
本研究聚焦于沿林分生产力梯度分布的黑云杉（P. mariana）生态系统中的土壤碳（soil C）稳定化机制。
研究将通过定量测定土壤中的炭化物质，明确火灾对土壤碳稳定化的长期影响。
此外，本研究将沿林分生产力梯度监测气候与土壤温度，并结合土壤室内培养试验，探究温度与生产力的交互作用对土壤碳稳定化的调控效应。
本研究的核心科学问题将通过三大研究模块展开：①林分生产力与景观位置的交互作用如何调控整个土壤剖面的碳稳定化过程；②火烧残余物对总碳累积的贡献如何随景观区域发生变化；③全景观尺度下地上生产力与火烧残余物之间的关联机制。
本研究的总体目标是，将北方针叶林碳储量的生物物理调控机制认知推广至景观尺度。