Collaborative Research: Nutritional Landscapes of Arctic Caribou: Observations, Experiments, and Models Provide Process-Level Understanding of Forage Traits and Trajectories

北极陆地系统是气候、植被、食草动物和人类之间复杂相互作用的结果，必须对它们进行综合研究，以了解它们的功能特征。虽然低温和短的生长季节限制了植物的生长，但有足够的植物生物量来支持阿拉斯加原住民赖以生存的迁徙驯鹿群。处于食物网底层的植物的任何变化都会对食草动物和人类消费者及其相互作用产生连锁反应。今天，北极系统正处于变化之中，导致新的植被组合，植物组织的营养价值发生变化，并最终改变了迁徙驯鹿和依赖它们的人类的饮食。本项目将北极中部驯鹿群的营养状况作为一个统一的概念进行考察，将营养状况描述为驯鹿可利用蛋白质（CAP）和驯鹿可利用能量。（CAE），综合饲料量测量，反映生物量，物种组成，植物&amp；#8232；C和N含量，消化率和次生化合物。核心目标是了解整个冻土带CAP和CAE数量的时空格局的驱动因素；驯鹿利用这片营养景观；在未来可能的气候情景和长期实验下，CAP和CAE的数量将如何变化，以及北美驯鹿和土著社区之间的相互作用。这项研究的广泛影响涉及阿拉斯加的几个利益相关者群体，包括：Nuiqsut北坡社区的采集者，世界各地的驯鹿社区，以及处于不同教育阶段的学生。该项目将安排一名团队成员与努伊克苏特的猎人一起工作。并制作一部关于北美驯鹿与阿拉斯加原住民互动的教育科学纪录片。高中生。该组织计划雇佣隶属于阿拉斯加本土科学协会的乡村学生和大学生。和工程计划，以协助实验工作和植被收集在图里克湖。这项研究对环北极野生动物监测中心的生态学家来说意义重大。和评估网络，专门的&amp；#8232；到美国、加拿大和斯堪的纳维亚的北美驯鹿保护和可持续管理，他们将利用这些数据来考虑一系列气候变化情景如何影响驯鹿群的繁殖力和种群动态。这个项目的智力价值源于五个要素的融合，以理解北极。系统功能及其对气候变化的响应：(1)植物物种、土壤和植物碳氮、消化率和次生化合物的景观尺度评估[amp；#8232]；计算CAP （kg m-2）和CAE （kJ m-2）的总量；(2)分析北美驯鹿的觅食与全年营养状况的密切关系；(3)样品分析&amp；#8232；从现有的长期冬季-夏季气候变化实验提供的数据如何；CAP和CAE在未来会有所不同；(4)预测未来的营养景观& &amp；#8232；驯鹿觅食的相互作用；(5)对阿拉斯加土著猎人的收获和属性的观察&amp；#8232；决定它们空间和时间模式的系统。这些项目的组成部分将使人们能够综合理解一种重要的食草动物驯鹿是如何与快速变化的景观相互作用的。本研究：(1)考察了北极系统从初级生产者到次级消费者的影响，并对北极系统从初级生产者到次级消费者的影响进行了分析。气候变化对多个营养水平的影响；(2)通过检查(&#8232；最丰富的大型食草动物及其食物来源，两者都分布在整个地区&amp；#8232；北极地区;(3)整合实验、观测和模拟方法来理解生态系统和气候变化。观察、实验数据的整合&amp；#8232；建立模型来描述当前和预测未来的营养状况是为了提供北极系统功能的机理认识与转化认识&amp；#8232；气候-植被-驯鹿-生存猎人的相互作用。

Terrestrial Arctic systems are the result of complex interactions between climate, vegetation, herbivores, and humans that must be studied together to understand their functional
traits. While low temperatures and short-growing seasons limit plant growth, enough plant biomass exists to support herds of migratory caribou, on which Alaska Natives depend. Any changes in the plants at the base of the food web can have cascading consequences for herbivores and human consumers and their interactions. Today, the Arctic system is in the midst of change resulting in new vegetation assemblages, changes in the nutritive value of plant tissues, and ultimately in the diets of migratory caribou and the humans that depend on them. This project examines the nutritional landscape of the Central Arctic Caribou Herd as a unifying concept, describing the nutritional landscape as caribou available protein (CAP) and caribou available energy
(CAE), integrative forage quantity measures that reflect biomass, species composition, plant
C and N content, digestibility, and secondary compounds. The core objectives are gaining understanding of the drivers of spatial and temporal patterns in the amounts of CAP and CAE across the tundra; caribou use of this nutritional landscape; how the amounts of CAP and CAE will differ in the future under likely climate scenarios and long-term experiments, and the interactions between caribou and Native communities. The broader impacts of this study involve several groups of Alaskan stakeholders, including: harvesters of the North Slope community of Nuiqsut, the worldwide caribou community, and students at multiple stages of education. The project will embed a team member with hunters in Nuiqsut,
and develop an educational scientific documentary on the caribou - Alaska Native interactions for
high school students. The group plans to employ village students and undergraduates affiliated with the Alaska Native Science
and Engineering Program to assist with experimental work and vegetation collection at Toolik Lake. This research is significant to ecologists from the Circumarctic Rangifer Monitoring
and Assessment Network, dedicated
to caribou conservation and sustainable management in the US, Canada, and Scandinavia, who will use the data to consider how a suite of climate change scenarios affect herd fecundity and population dynamics. The intellectual merit of this project stems from the merging of five elements to understand Arctic
System function and response to climate change: (1) A landscape-scale assessment of plant species, soil and plant C and N, digestibility, and secondary compounds that will be used
to calculate the amounts of CAP (kg m-2) and CAE (kJ m-2); (2) analysis of how closely caribou foraging is tied to the nutritional landscape throughout the year; (3) analysis of samples
from an existing long-term winter - summer climate change experiment to provide data on how
CAP and CAE will differ in the future; (4) prediction of future nutritional landscapes and
caribou foraging interactions; and (5) observations of Alaska Native hunter harvesting and attributes
of the system that determine their spatial and temporal patterns. These project components will enable an integrative understanding of how an important herbivore, caribou, interact with a landscape that is rapidly changing. This research: (1) examines the Arctic System from primary production to secondary consumers and the
influence of climate change across multiple trophic levels; (2) applies broadly by examining
the most abundant large herbivore and its food sources, both of which are distributed throughout
the Arctic; and (3) integrates experimental, observational, and modeling approaches to understanding ecological systems and climate change. The integration of observation, experimental data
and modeling to describe current and forecast future nutritional landscapes is intended to provide a
mechanistic understanding of Arctic System function and transform the understanding
of climate-vegetation-caribou-subsistence hunter interactions.