Collaborative Research: Shifting seasonality of Arctic river hydrology alters key biotic linkages among aquatic systems

该奖项是根据2009年《美国复苏和再投资法案》(公法111-5)资助的。这项研究将确定北极河流水文的季节性变化如何改变流域湖泊和溪流组成部分内部和之间的关键生物联系，并可能改变北极系统的功能。北极灰鲸(Thymallus Arcticus)是一种典型的北极圈物种，它为理解季节性变化对北极生态系统功能的影响提供了一个模式系统，因为维持它们的种群生存需要相互关联和多样化的地貌(大苔原河流、小溪和湖泊)。破坏其迁徙的环境条件的变化将影响水生生态系统的系统级功能。灰鲸是其他生物群的食物，包括湖鲑鱼、鸟类和人类，也是河流生态系统中自上而下的控制者，这表明它们种群的变化将对整个耦合的河湖系统产生影响。现在影响冻土带湖泊和溪流的变化的规模和速度使人们迫切需要了解它们是如何联系在一起的，以及它们是如何作为一个系统发挥作用的。这项工作将解决4个问题：1)气候变化如何影响灰熊迁徙的季节性、速率和距离？2)生命周期的季节性，河流昆虫种群的生活史和属性随气候变化而变化？3)河流流量的季节性变化如何与昆虫生产相互作用，影响河流生产的可获得性和向灰熊的转移？4)气候驱动的迁徙环节中断对冬季避难所结构和功能的影响？研究人员将通过以下几个方面研究气候变化对关键生物联系的影响：1)河流流量和温度以及昆虫和鱼类生产力和迁徙的长期数据库的回顾研究，2)关于迁徙季节性控制的新工作，河流生产力和营养转移；3)关于冬季避难所开放水季变化和食物网之间反馈的新工作。这将被集成到一个系统级模型中，以格雷林为货币，以评估系统组件之间的联系改变对系统级功能的影响。该项目更广泛的智力优势在于整合了不同领域(水文学、动物生理学、种群生物学和数学建模)的工作，以了解物种在生态系统中的作用。通过生物联系更好地理解湖泊和河流生产力的相互依存关系，将促进我们对景观生态学、动物在生态系统动力学、生命历史演变和渔业生态系统管理中的作用的总体理解。

AbstractThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This research will determine how the shifting seasonality of arctic river hydrology alters key biotic linkages within and among lake and stream components of watersheds and may alter the function of the arctic system. Arctic grayling (Thymallus arcticus) is a quintessential, circumpolar arctic species that provides a model system for understanding the impacts of changing seasonality on arctic ecosystem function because an interconnected and varied landscape (large tundra rivers, small streams and lakes) is required to maintain their population viability. Changes to environmental conditions that disrupt their migration will affect the system-level function of aquatic ecosystems. Grayling serve as food for other biota, including lake trout, birds and humans, and as top-down controls in stream ecosystems suggesting that changes to their populations will have effects that reverberate throughout the coupled river-lake system. The scale and pace of the changes now impacting tundra lakes and streams imparts an urgency to understand how they are linked and how they function as a system.This work will address 4 questions: 1) How are seasonality, rate and distance of grayling migration affected by climate change? 2) Are the seasonality of life-cycles, life-history and attributes of stream insect populations changing in response to climate change? 3) How does changing seasonality of river discharge interact with insect production to affect availability and transfer of stream production to grayling? 4) What is the effect of climate driven disruption of the migratory link on the structure and function of winter refugia?Reseachers will examine the implications of changing climate on key biotic linkages by: 1) retrospective studies of long-term databases of stream flow and temperature and insect and fish productivity and migration, 2) new work on controls on seasonality of migration, stream productivity and trophic transfer and 3) new work on the feedbacks between changing open water season and food webs in winter refugia. This will be integrated into a systems-level model, using grayling as the ?currency?, to evaluate the effects of altered linkages among system components on system level functioning.The broader intellectual merit of this project lies in the integration of work from diverse fields (hydrology, animal physiology, population biology and mathematical modeling) to understand the roles of species in ecosystems. Improved understanding of the interdependence of lake and stream productivity through biotic linkages will advance our general understanding of landscape ecology, the role of animals in ecosystem dynamics, life-history evolution and ecosystem management of fisheries.