Fire in Northern Alaska: Effect of a Changing Disturbance Regime on a Regional Macrosystem

在过去的50年里，北方阿拉斯加的气温上升伴随着野火频率的增加，在过去的60年里，北坡一半以上的火灾活动发生在2000年以后。 人们对火灾对该地区碳和能源平衡的影响知之甚少，因为火灾发生在偏远地区，规模较小，而且相对不频繁。 北极生态系统储存的碳是目前大气中的两倍，通过与大气交换碳，并通过影响苔原表面的反射率和热量渗透到永久冻土中，影响当地和区域气候。 火灾有可能改变平衡，通过燃烧将碳释放到大气中，通过植被和土壤变化减少碳固存，并通过使表面变暗和吸收更多的太阳能来影响气候。 这项研究的目标是更好地了解火灾对北极苔原的短期（每日至每年）和长期（数十年至百年）影响。这一目标将通过结合在阿拉斯加北坡和苏厄德半岛不同年代的燃烧地点进行的实地测量，沿着最近和历史上的卫星和飞机遥感图像来实现，该项目开发的模型可以通过预测未来变化的影响来为未来的管理决策提供信息。火灾对北极生态系统服务的影响。 它将揭示不仅与气候变化有关的全球人口相关的过程和相互作用，而且还与依赖北坡景观维持其生存生活方式的当地美洲原住民人口相关。 一些博士后和本科生研究人员将接受培训，并为北极长期生态研究项目和海洋生物实验室目前开展的外联方案做出贡献。 这些贡献包括在互联网上分发收集的数据和创建的模型，以及在当地阿拉斯加原住民社区举办公开讲座和课堂练习。

Increased temperatures in Northern Alaska over the past 50 years have been accompanied by an increase in the frequency of wildfires, with over half of the fire activity on the North Slope in the past 60 years occurring since 2000. The effects of fire on carbon and energy balances in this region are poorly understood, as the fires have occurred in remote regions, been small in size, and are relatively infrequent. Arctic ecosystems store twice the amount of carbon currently in the atmosphere and affect the local and regional climate by exchanging carbon with the atmosphere and through their impacts on the reflectivity of the tundra surface and heat penetration into permafrost soils. Fires have potential to alter the balances by releasing carbon into the atmosphere through combustion, reducing carbon sequestration through vegetation and soil changes, and influencing climate by darkening the surface and allowing more solar energy to be absorbed. The goal of this research is to develop a better understanding of the short-term (daily to annual) and long-term (decadal to centennial) effects of fire on Arctic tundra. The goal will be met by combining field measurements made at burned sites of different age on the North Slope and Seward Peninsula of Alaska, along with recent and historical satellite and aircraft remotely sensed imagery, into predictive models of how fires influence carbon and energy cycling over time across the Arctic.The models developed in this project can be used to inform future management decisions by predicting the impacts of future changes in the frequency of fires on ecosystem services in the Arctic. It will reveal processes and interactions that are relevant not only to the global human population as related to climate change, but also to the local Native American populations that depend on the North Slope landscape to sustain their subsistence lifestyles. Several postdoctoral and undergraduate researchers will be trained and contributions made to outreach programs currently run by the Arctic Long-Term Ecological Research project and the Marine Biological Laboratory. These contributions include internet-based distribution of data collected and models created, as well as public lectures and classroom exercises in local Native Alaskan communities.