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个极地沙漠，该地区尚未经历气候变暖。麦克默多干谷长期生态研究项目记录了在与大气臭氧消耗有关的变冷趋势期间（1986年至2000年），MDV中冰川、土壤、河流和湖泊生态系统的生态反应。在过去十年中，有两个夏季发生了伴随着强烈下吹风的变暖事件，由此产生的高流量和沉积物沉积改变了干旱河谷的地貌，这可能预示着臭氧洞恢复时将出现的状况。在南极洲未来变暖的预期中，拟议项目的总体假设是：气候变暖的麦克默多干谷生态系统将放大景观单元之间的连接，导致增强耦合的营养循环景观，并增加生态系统内的生物多样性和生产力。 MDV的变暖被假设为一个缓慢发展的，长期的夏季变暖的压力，在此之上，夏季高流量和强烈的下降风的瞬态脉冲事件将被叠加。四个具体的假设讨论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。 由于生物区系的风载迁移是加强与下降风的联系的一个关键方面，新的监测将包括对风成粒子通量的高分辨率测量。重要的是，整合基因组学将用于了解特定生物体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，将使用环境历史来研究人类活动，科学研究和过去100年MDV环境变化之间的相互作用。为了广泛传播这项研究，MCM科学家将参与广泛的外联工作，从K-12教室的演讲到将本科生和教师带到MDV以获得研究经验。计划的推广方案将以国际极地年（2007-2008年）期间开展的活动为基础，其中包括为高中学生和教师制作互动DVD，并在LTER校园丛书中出版一本儿童读物。将分发这本书的教师版，并附有一张载有教案的光盘。该项目将通过出版一些西班牙语的宣传材料，为传统上在科学领域代表性不足的群体制定计划。

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.