Collaborative Research: Vegetation And Ecosystem Impacts On Permafrost Vulnerability

在未来气候情景下，永久冻土生态系统中热交换的非技术性现实表示对于准确预测永久冻土碳反馈是必要的。该项目将对植被和地貌特征对永久冻土热状况的影响进行泛北极定量评估。通过跨生态系统，景观特征和区域的工作，研究将确定广泛的趋势，密集的能量平衡站点将提供生态系统对永久冻土响应气候变化的影响的机制研究。通过将研究结果纳入区域和特定地点的永久冻土模型和综合活动，将加强这项研究的影响，这些活动将研究生态系统对能量平衡的影响和永久冻土对气候变化的脆弱性。这项工作将对科学界和公众产生广泛的影响，因为它汇集了全球环境中的重要问题，并提高了对生态系统动态与冻土融化之间联系的认识。拟议的项目将通过研究人员与NSF资助的本科生实地研究经验之间的合作，为本科生提供培训机会。作为这项工作的一部分，研究人员将指导几名学生，并将在一个以本科为主的机构教授两门北极系统科学课程。该项目将通过与教育中心、当地社区，特别是教师和外联协调员的持续合作，提高科学认识。随着气候变暖，预计永久冻土分布将显著减少，但在未来气候情景下，确定永久冻土的命运仍存在很大的不确定性。这些不确定性在很大程度上是由调节气候对冻土温度影响的植被和生态系统特性驱动的。对冻土温度的长期监测表明了这些当地条件的重要性，但一直没有泛北极的努力，以测量生态和景观变量与冻土温度监测。该项目将结合使用实地和遥感数据，以解决植被和景观因素如何调节冻土温度对气候变化的反应的问题。为了解决这个问题，研究人员将结合广泛的泛北极植被-永久冻土动态评估，深入研究灌木和乔木冠层覆盖对生态系统能量平衡的影响。这项研究的第一部分将在西伯利亚和阿拉斯加的长期冻土温度监测点进行，第二部分，作为本提案的一部分，将建立的植被能量平衡点，将在西伯利亚的灌木树冠覆盖梯度进行，那里是大多数冻土区的所在地。这些深入研究的能量平衡网站将提供一个更好的机制的理解生态系统组件的影响，这些组件之间的相互作用，生态系统能量平衡和永久冻土对气候变化的脆弱性。这一机制的知识，反过来，支持通过泛北极采样的永久冻土温度监测站点观察到的广泛模式的解释。

NontechnicalRealistic representations of heat exchange in permafrost ecosystems are necessary for accurate predictive understanding of the permafrost carbon feedback under future climate scenarios. This project will provide a quantitative pan-arctic assessment of the effects of vegetation and landscape characteristics on permafrost thermal regimes. By working across ecosystems, landscape characteristics, and regions, the research will identify broad trends, and intensive energy balance sites will provide a mechanistic study of ecosystem impacts on permafrost response to climate change. The impacts of this study will be enhanced through integration of research results into regional and site-specific permafrost models and synthesis activities that will examine ecosystem impacts on energy balance and permafrost vulnerability to climate change. This work will have broad impacts on the scientific community and general public because it brings together important issues in the global environment and raises awareness of the connection between ecosystem dynamics and permafrost thaw. The proposed project will provide training opportunities for undergraduate students through collaboration between the researchers and an NSF funded field research experience for undergraduates. The researchers will mentor several students as part of this proposed work and will also teach two arctic system science courses at a predominantly undergraduate institution. This project will enhance scientific understanding through continued work with education centers, local communities and, in particular, with teachers and outreach coordinators. TechnicalSignificant declines in permafrost distribution are expected as the climate warms, but large uncertainties remain in determining the fate of permafrost under future climate scenarios. These uncertainties are driven, in large part, by vegetation and ecosystem properties that modulate the effect of climate on permafrost temperatures. Long-term monitoring of permafrost temperatures demonstrates the importance of these local conditions, yet there has been no pan-arctic effort to measure ecological and landscape variables in concert with permafrost temperature monitoring. This project will use a combination of field and remotely-sensed data to address the question of how vegetation and landscape factors modulate permafrost temperature response to climate change. To address this question the researchers will couple an extensive pan-arctic assessment of vegetation-permafrost dynamics with an intensive study of shrub and tree canopy cover effects on ecosystem energy balance. The first component of this research will be conducted at long-term permafrost temperature monitoring sites in Siberia and Alaska, and the second component, the vegetation-energy balance sites that will be established as part of this proposal, will be conducted at a shrub-tree canopy cover gradient in Siberia, where most permafrost regions are located. These intensively studied energy balance sites will provide an improved mechanistic understanding of the effects of ecosystem components, and interactions among these components, on ecosystem energy balance and permafrost vulnerability to climate change. This mechanistic knowledge will, in turn, support interpretation of broad patterns observed through a pan-arctic sampling of the permafrost temperature monitoring sites.