Collaborative Research: Effects of warming-induced increases in shrub abundance and changing seasonality on migratory songbirds in Alaskan arctic tundra.

合作研究：变暖引起的灌木丰度增加和季节性变化对阿拉斯加北极苔原迁徙鸣禽的影响。

• 批准号: 0909133
• 负责人: Marilyn Ramenofsky
• 金额: $ 33.21万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0909133&HistoricalAwards=false
• 关键词: Collaborative; Research; Effects; warming; induced

As a consequence of global warming, arctic North America has been ?greening? over the past several decades, with increases in relative abundance and size of shrubs documented in numerous locations. Much of the research on this topic examines how this shift toward more woody species affects element cycling, particularly carbon, with potential feedbacks to the atmosphere regionally and globally. To date, the response of higher trophic levels to such shifts in vegetation in the Arctic has not been well studied. One group that has been almost completely ignored is migratory songbirds; they have a complex relationship with shrubs that provide both shelter and food, both of which are directly affected by weather patterns. This research will characterize the interactions between tundra vegetation and migratory songbirds in habitats that differ in shrub dominance for five consecutive growing seasons that will differ in timing and severity of weather events. The team will 1) identify and characterize interactions between shrub dominance and weather to determine how these affect food and shelter availability for migratory songbirds; 2) examine how reproductive success of populations of two songbird species responds to variation in both shrub dominance and timing of spring snowmelt, and; 3) measure how both variation in shrub dominance and timing of spring snowmelt affect composition and size of the entire songbird community. The multi-year approach will allow for examination of how interannual variability in arctic seasonality, particularly the timing of snowmelt, impacts songbird communities. Because the increasing shrub dominance is occurring too slowly for organisms to respond to during the time period of a grant, the researchers will examine habitat usage in open tundra plots, moderate shrub dominance plots, and high shrub dominance plots, at each of four study sites on the North Slope of Alaska. These include Atigun Valley, one of the first tundra stops made by migratory songbirds as they travel north, and at Toolik Lake, farther north, including two additional sites farther north to increase the spatial scale of sampling. In five project years, they will sample intensively at all four field sites to investigate spatial and temporal variation in plant resources, arthropod abundance, songbird community composition, and the arrival, settlement and reproductive success of two songbird species. During five years they hope to capture a range of interannual variability in weather, onset of spring snowmelt, and biotic responses to provide and understanding of current relationships and to predict how future changes in climate and vegetation may affect these organisms. They also intend to verify the use of remote techniques for monitoring bird community attributes via bioacoustic recordings for conducting automated bird community censuses.

由于全球变暖，北极北美一直是绿色？在过去的几十年中，相对丰度和灌木的大小增加了许多位置。关于该主题的大部分研究都研究了这种向更木质物种的转变如何影响元素循环，尤其是碳，并在区域和全球范围内可能会反馈大气。迄今为止，尚未对北极中较高的营养水平对这种植被转移的反应进行很好的研究。几乎完全被忽略的一组是迁徙鸣禽。他们与提供庇护所和食物的灌木具有复杂的关系，两者都直接受到天气模式的影响。这项研究将表征苔原植被与栖息地中迁徙的鸣禽之间的相互作用，这些栖息地连续五个生长季节在灌木上占主导地位，这在天气事件的时间和严重程度上会有所不同。团队将1）确定并表征灌木占优势与天气之间的相互作用，以确定这些养殖鸟的食物和庇护所如何影响； 2）检查两个鸣禽种群的生殖成功如何应对灌木融雪的灌木占主导地位和时机的变化，以及； 3）衡量灌木的占主导地位和春天融雪的时机的变化如何影响整个鸣禽社区的大小。多年的方法将允许检查北极季节的年际变化，尤其是融雪的时机如何影响鸣禽社区。由于增加的灌木占优势的发生速度太慢，无法在赠款期间对生物响应，因此研究人员将在阿拉斯加北坡上的四个研究地点中的每个研究地点中的每个研究地点，都会检查开放的苔原图，中等灌木占优势地和高灌木占优势地的栖息地。其中包括Atigun Valley，这是迁徙鸣禽向北行驶的第一批苔原停靠点之一，在北部的Toolik Lake上，包括北部的其他两个地点，以增加抽样的空间规模。在五年的项目中，他们将在所有四个场地上进行深入的品尝，以研究植物资源，节肢动物丰度，鸣禽社区组成以及两个鸣禽物种的到达，沉降和生殖成功的空间和时间变化。在五年中，他们希望捕获天气，春天融雪的发作以及生物反应的一系列年际变化，以提供和理解当前关系，并预测气候和植被的未来变化如何影响这些生物。他们还打算通过生物声学记录来验证使用远程技术来监视鸟类社区属性，以进行自动鸟社区人口普查。