LTER: PALMER, ANTARCTICA LTER: Climate Change, Ecosystem Migration and Teleconnections in an Ice-Dominated Environment

LTER：南极洲帕尔默 LTER：以冰为主的环境中的气候变化、生态系统迁移和遥相关

• 批准号: 0217282
• 负责人: Hugh Ducklow
• 金额: $ 429万
• 依托单位: College of William & Mary Virginia Institute of Marine Science
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-10-15 至 2009-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0217282&HistoricalAwards=false
• 关键词: LTER; PALMER; ANTARCTICA; Climate; Change

The Palmer, Antarctica, Long-Term Ecological Research Project (PAL) seeks to understand the structure and function of the Western Antarctic Peninsula's marine and terrestrial ecosystems in the context of seasonal-to-interannual atmospheric and sea ice dynamics, as well as long-term climate change. The PAL measurement system (or grid) is designed to study marine and terrestrial food webs consisting principally of diatom primary producers, the dominant herbivore Antarctic krill, and the apex predator Adelie penguin. An attenuated microbial food web is also a focus. PAL studies these ecosystems annually over a regional scale grid of oceanographic stations and seasonally at Palmer Station. Sea ice extent and variability affects ecosystem changes at all trophic levels. In recent years, sea ice extent has diminished in response to a general warming in the region. Long-term population trends of ice-dependent Adelie penguins in the region provide a clear example of impact of the climate warming trend in the in the region. Adelie populations at the five major colonies studied near Palmer Station have all shown a gradual decrease in numbers over thirty years. The Peninsula runs perpendicular to a strong climatic gradient between the cold, dry continental regime to the south, characteristic of the Antarctic interior, and the warm, moist, maritime regime to the north. North-south shifts in the gradient give rise to large environmental variability to climate change. Currently more maritime conditions appear to be replacing the original polar ecosystem in the northern part of the peninsula as the climatic gradient shifts southward. To date, this shift appears matched by an ecosystem shift along the peninsula, as evidenced by declines in Adelie populations that require longer snow-cover seasons for successful recruitment. The main hypothesis is that ecosystem migration is most clearly manifested by changes in upper level predators (penguins) and certain polar fishes in predator foraging environments. This is because these longer lived species integrate recent climate trends and because individual species are more sensitive indicators than aggregated functional groups. Analogous modifications are expected to be manifested at lower trophic levels in the marine parts of the system in the years ahead. However, these lower level changes are likely to be observed only through long-term observations consistent with the concept of expansion and contraction of ecosystem boundaries along the Peninsula. The PAL-LTER will continue to investigate ecosystem changes at lower trophic levels along the Peninsula, in response to the continued, dramatic climate warming and pole ward shifts in the climatic gradient. In addition to the long-term research activities, graduate student training, the involvement of K-12 teachers and web-based education are an integral part of the PAL-LTER.

南极帕尔默长期生态研究项目(PAL)旨在了解南极半岛西部海洋和陆地生态系统在季节和年际大气和海冰动态以及长期气候变化背景下的结构和功能。PAL测量系统(或网格)旨在研究海洋和陆地食物网，主要由硅藻初级生产者、主要食草性南极磷虾和顶端捕食者阿德利企鹅组成。一个弱化的微生物食物网也是一个焦点。PAL每年在区域尺度的海洋站网格上研究这些生态系统，并在帕尔默站季节性地进行研究。海冰范围和可变性影响所有营养级别的生态系统变化。近年来，由于该地区普遍变暖，海冰面积已经缩小。该区域依赖冰的阿德利企鹅的长期种群趋势清楚地说明了气候变暖趋势对该区域的影响。在帕尔默站附近研究的五个主要殖民地的阿德利种群都显示出在过去30年中数量逐渐减少的趋势。该半岛垂直于南极内陆特有的南部寒冷干燥的大陆体系和北部温暖潮湿的海洋体系之间的强烈气候梯度。梯度的南北变化导致气候变化的环境变异性很大。目前，随着气候梯度向南转移，更多的海洋条件似乎正在取代半岛北部原来的极地生态系统。到目前为止，这一转变似乎与半岛上的生态系统转变相匹配，阿德利人的减少就是明证，阿德利人需要更长的雪季才能成功招募。主要的假设是，生态系统的迁移最明显地表现为上层捕食者(企鹅)和某些极地鱼类在捕食者觅食环境中的变化。这是因为这些寿命较长的物种结合了最近的气候趋势，而且单个物种比聚集的官能团更敏感。预计在未来几年，类似的修改将在该系统海洋部分的较低营养水平表现出来。然而，只有通过符合半岛生态系统边界扩张和收缩概念的长期观察，才可能观察到这些较低水平的变化。PAL-LTER将继续调查半岛较低营养级别的生态系统变化，以应对持续的、戏剧性的气候变暖和气候梯度的极地变化。除了长期的研究活动外，研究生培训、K-12教师的参与和基于网络的教育也是PAL-LTER的组成部分。