Increased Connectivity in a Polar Desert Resulting from Climate Warming: McMurdo Dry Valley LTER Program

麦克默多干谷(MDV)是南极洲东部海岸的一片极地沙漠，该地区尚未经历气候变暖。麦克默多干谷长期生态研究(MCMLTER)项目记录了MDV冰川、土壤、溪流和湖泊生态系统在降温趋势(从1986年到2000年)期间的生态反应，这与大气臭氧的耗尽有关。在过去的十年中，两个夏季都发生了带有强烈降温风的变暖事件，由此产生的高水流和沉积物沉积改变了干燥的山谷地貌，可能预示着臭氧空洞恢复时将发生的条件。由于对南极洲未来变暖的预期，拟议项目的首要假设是：麦克默多干谷生态系统的气候变暖将扩大景观单元之间的联系，从而增强不同景观之间的营养循环耦合，并增加生态系统内的生物多样性和生产力。MDV的变暖被认为是一个缓慢发展的、长期的夏季变暖的压力，在此基础上，夏季高流量和强风的瞬时脉冲事件将被叠加。四个具体的假设阐述了水和风的脉动将如何影响当代和未来的生态系统结构、功能和连通性。由于生物群的风载运输是从卡塔尔风增强连通性的一个关键方面，新的监测将包括对风沙颗粒通量的高分辨率测量。重要的是，综合基因组学将被用来了解特定生物对增加的连接性的反应。该项目还将包括一个新的社会科学组成部分，将使用环境历史来审查过去100年来MDV中人类活动、科学研究和环境变化之间的相互作用。为了广泛传播这项研究，MCM科学家将参与一系列广泛的外展工作，从在K-12课堂上的演讲到将本科生和教师带到MDV获得研究经验。计划中的外联方案将以国际极地年(2007-2008年)期间开展的活动为基础，其中包括为高中生和教师制作互动DVD，以及在LTER校园丛书中出版一本儿童读物。这本书的教师版连同一张包含教案的CD将被分发。该项目将通过以西班牙语发布一些外联材料，为在科学领域传统上代表性较低的群体制定计划。

The McMurdo Dry Valleys (MDV) is a polar desert on the coast of East Antarctica, a region that has not yet experienced climate warming. The McMurdo Dry Valleys Long Term Ecological Research (MCMLTER) project has documented the ecological responses of the glacier, soil, stream and lake ecosystems in the MDV during a cooling trend (from 1986 to 2000) which was associated with the depletion of atmospheric ozone. In the past decade, warming events with strong katabatic winds occurred during two summers and the resulting high streamflows and sediment deposition changed the dry valley landscape, possibly presaging conditions that will occur when the ozone hole recovers. In anticipation of future warming in Antarctica, the overarching hypothesis of the proposed project is: Climate warming in the McMurdo Dry Valley ecosystem will amplify connectivity among landscape units leading to enhanced coupling of nutrient cycles across landscapes, and increased biodiversity and productivity within the ecosystem. Warming in the MDV is hypothesized to act as a slowly developing, long-term press of warmer summers, upon which transient pulse events of high summer flows and strong katabatic winds will be overprinted. Four specific hypotheses address the ways in which pulses of water and wind will influence contemporary and future ecosystem structure, function and connectivity. Because windborne transport of biota is a key aspect of enhanced connectivity from katabatic winds, new monitoring will include high-resolution measurements of aeolian particle flux. Importantly, integrative genomics will be employed to understand the responses of specific organisms to the increased connectivity. The project will also include a novel social science component that will use environmental history to examine interactions between human activity, scientific research, and environmental change in the MDV over the past 100 years. To disseminate this research broadly, MCM scientists will participate in a wide array of outreach efforts ranging from presentations in K-12 classrooms to bringing undergraduates and teachers to the MDV to gain research experience. Planned outreach programs will build upon activities conducted during the International Polar Year (2007-2008), which include development of an interactive DVD for high school students and teachers and publication of a children's book in the LTER Schoolyard Book Series. A teacher's edition of the book with a CD containing lesson plans will be distributed. The project will develop programs for groups traditionally underrepresented in science arenas by publishing some outreach materials in Spanish.