CAREER: Energy fluxes and community stability in a dynamic, high-latitude kelp ecosystem

高纬度海藻森林支持着丰富的生态和经济重要物种，缓冲着海岸线免受高能量风暴的影响，并通过隔离和储存大量碳在海洋碳循环中发挥关键作用。了解这些海带群落中的能量流动和消费者-资源相互作用如何变化，对于制定有助于维持这些有价值的生态系统服务的强有力的管理战略至关重要。在这一综合研究和教育计划中，项目团队将调查消费者群体如何对温度、碳酸盐化学和资源质量的变化做出反应，以影响海带森林的食物网和生态系统稳定性。在阿拉斯加东南部巨藻(Macrocystis Pyrifera)的北部活动范围内进行的一系列综合研究将考察海藻群落如何应对季节变化以及不断变化的海洋温度和酸化条件引起的不同环境条件。作为该项目的一部分，本科生和高中生将通过(1)在阿拉斯加州锡特卡湾的身临其境的实地课程，(2)强化的、有指导的研究实习，以及(3)科学传播和公共宣传的体验式培训，包括通过播客、公共讲座和广播传播研究成果的各种机会，接受全面的培训。消费者-资源相互作用构成了食物网并管理着生态系统的稳定性，然而，我们对这些重要相互作用在未来气候条件下可能如何变化的理解受到营养水平内和营养水平之间多种压力的直接和间接影响的复杂性的阻碍。例如，环境调节的初级生产者营养质量变化和化学威慑有可能改变初级生产者和消费者之间的草食率和能量流动，从而影响生态系统的稳定性。此外，全球变化对初级生产者的影响可能取决于其他限制资源，如光和养分，这些资源在动态、温带和高纬度生态系统中随季节变化。在高纬度的海洋生态系统中，气候模型预测，海洋酸化将在冬季几个月最为明显，因为冬季初级生产力受到光照的限制。该项目建立在这样的假设之上，即气候变暖和海洋酸化可能导致主要消费者的能源需求与冬季几个月的资源可获得性和质量不匹配，并对未来的营养结构和生态系统稳定性产生连锁影响。通过补充实验室和实地实验，项目组将确定1)温度和碳酸盐化学如何结合在一起影响各种物种的初级消费者生物能量；2)海洋酸化和变暖通过环境中介的初级生产者在不同季节的可获得性、营养质量和适口性的变化对初级消费者的间接影响。利用实验室和实地实验的数据，项目团队将3)在季节性动态的高纬度环境中构建一个关于气候变暖和海洋酸化对营养结构和生态系统稳定性的紧急影响的模型。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

High latitude kelp forests support a wealth of ecologically and economically important species, buffer coastlines from high-energy storms, and play a critical role in the marine carbon cycle by sequestering and storing large amounts of carbon. Understanding how energy fluxes and consumer-resource interactions vary in these kelp communities is critical for defining robust management strategies that help maintain these valuable ecosystem services. In this integrated research and education program, the project team will investigate how consumer populations respond to variability in temperature, carbonate chemistry and resource quality to influence the food webs and ecosystem stability of kelp forests. A comprehensive suite of studies conducted at the northern range limit for giant kelp (Macrocystis pyrifera) in SE Alaska will examine how kelp communities respond to variable environmental conditions arising from seasonal variability and changing ocean temperature and acidification conditions. As part of this project, undergraduate and high school students will receive comprehensive training through (1) an immersive field-based class in Sitka Sound, Alaska, (2) intensive, mentored research internships, and (3) experiential training in science communication and public outreach that will include a variety of opportunities to disseminate research findings through podcasts, public lectures and radio broadcasts. Consumer-resource interactions structure food webs and govern ecosystem stability, yet our understanding of how these important interactions may change under future climatic conditions is hampered by the complexity of direct and indirect effects of multiple stressors within and between trophic levels. For example, environmentally mediated changes in nutritional quality and chemical deterrence of primary producers have the potential to alter herbivory rates and energy fluxes between primary producers and consumers, with implications for ecosystem stability. Moreover, the effects of global change on primary producers are likely to depend on other limiting resources, such as light and nutrients, which vary seasonally in dynamic, temperate and high latitude ecosystems. In marine ecosystems at high latitude, climate models predict that ocean acidification will be most pronounced during the winter months, when primary production is limited by light. This project is built around the hypothesis that there could be a mismatch in the energetic demands of primary consumers caused by warming and ocean acidification and resource availability and quality during winter months, with cascading effects on trophic structure and ecosystem stability in the future. Through complementary lab and field experiments, the project team will determine 1) how temperature and carbonate chemistry combine to affect primary consumer bioenergetics across a diversity of species and 2) the indirect effects of ocean acidification and warming on primary consumers via environmentally mediated changes in the availability, nutritional quality and palatability of primary producers across seasons. Using the data from the laboratory and field experiments, the project team will 3) construct a model of the emergent effects of warming and ocean acidification on trophic structure and ecosystem stability in seasonally dynamic, high latitude environments.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.