Methods and Applications for Assessing Ecosystem Impacts of Natural Climate Fluctuations and Human Activities with Emphasis on Western Canada

评估自然气候波动和人类活动对生态系统影响的方法和应用，重点是加拿大西部

• 批准号: RGPIN-2014-05486
• 负责人: Routledge, Rick
• 金额: $ 1.02万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=635844
• 关键词: Methods; Applications; Assessing; Ecosystem; Impacts

My recent research has generated (i) fundamental insight on ecosystem interactions associated with pressing conservation concerns, and (ii) a valuable statistical tool for use in ecosystem research. Much of this research was focused on the severely depressed, Oweekeno Lake sockeye salmon population on the British Columbia Central Coast. I intend to pursue a particularly significant finding regarding the ecosystem interactions in the seaward migration of these sockeye salmon to ascertain the extent to which these might be common to other populations. I also intend to make significant improvements to widely useful statistical methodology that emerged from this project. Finally, I propose to pursue several, unanticipated but strong hints of an impact of the 18.6-year lunar nodal cycle on both aquatic and terrestrial ecosystems in western Canada. I provide a summary of the last two of these challenges below.Research Question: Can tightened simultaneous confidence bounds be developed for functional regression analyses? There are many instances where insight is sought on the relationship between a physical parameter (such as river discharge) that is monitored daily and a biological variable (such as marine survival for an out-migrating cohort of sockeye salmon). Is, e.g., river discharge linked to marine survival? And if so, over what portion of the year? Functional regression analysis links an x-variable that is in fact a function over time (daily river discharge), to a y-variable (annual marine survival), and provides a means for addressing these questions. In this analysis, the regression coefficient in a standard linear regression equation is replaced by a function over time. The second question above then becomes, "For which days is the regression function non-zero? ". This is a simultaneous inference problem, akin to standard multiple comparisons of means associated with an analysis of variance. The approach that I and two others proposed recently provides appropriate protection against false claims of significance, but is relatively conservative (akin to Scheffé's method for multiple comparisons of means). I propose to use so-called tube-based, analytical methods to reduce this conservatism. Our proposal is already gaining traction, and such an improvement would enhance its utility.Research Question: To what extent does the 18.6-year lunar nodal cycle (in the relative orientations of the apparent paths of the moon vs. the sun) influence terrestrial and aquatic ecosystems in Western North America? Potential oceanographic and climate-related impacts of this cycle have recently been described, including sea surface and atmospheric impacts along the Pacific Coast of North America, and potential causal mechanisms have been modeled. I, in collaboration with others, have found strong hints of periodic fluctuations in several aquatic and terrestrial ecosystems in western Canada, including (i) a proxy for juvenile sockeye salmon abundance in a rearing lake, (ii) nitrogen concentrations in a coastal flood plain, (iii) charcoal concentrations in an inland lake, and (iv) tree growth rates in the lake watershed. I have also found similar periodicities in an ad hoc analysis of archived records for the growth of subalpine fir and black spruce in north-western Canada. I intend to pursue this remarkable, serendipitous discovery by (i) generating further, finer-resolution and longer time series for the proxy for salmon abundance, (ii) performing a more rigorous and extensive assessment of the archived tree growth records, and (iii) collecting further evidence from the area where the above tree-growth dependence appears to be strongest – in the northwest corner of British Columbia and adjacent Yukon Territory.

我最近的研究产生了（i）与紧迫的保护问题相关的生态系统相互作用的基本见解，（ii）用于生态系统研究的有价值的统计工具。这项研究的大部分集中在不列颠哥伦比亚省中央海岸严重抑郁的Oweekeno湖红鲑鱼种群上。我打算追求一个特别重要的发现，这些红鲑向海迁移的生态系统的相互作用，以确定在何种程度上，这些可能是共同的其他人群。我还打算对这一项目产生的广泛有用的统计方法作出重大改进。最后，我建议追求几个，意想不到的，但强烈的暗示18.6年的月球交点周期的影响，在加拿大西部的水生和陆地生态系统。我提供了一个总结的最后两个这些challenges.Research问题：可以收紧同步置信界限开发的功能回归分析？在许多情况下，人们寻求了解每天监测的物理参数（如河流流量）与生物变量（如红鲑鱼向外迁移的海洋生存）之间的关系。例如，河流排放与海洋生存有关？如果是这样，在一年中的哪一部分？函数回归分析将实际上是随时间变化的函数的x变量（每日河流流量）与y变量（年度海洋生存）联系起来，并提供了解决这些问题的方法。在该分析中，标准线性回归方程中的回归系数被替换为随时间变化的函数。上面的第二个问题就变成了，“回归函数在哪几天是非零的？".这是一个同时推理问题，类似于与方差分析相关的平均值的标准多重比较。我和另外两个人最近提出的方法提供了适当的保护，防止虚假的显著性声明，但相对保守（类似于Scheffé的多重比较方法）。我建议使用所谓的基于管道的分析方法来减少这种保守性。我们的建议已经获得牵引力，这样的改进将提高其utility.Research问题：在多大程度上18.6年的月球交点周期（在相对方向的明显路径的月球与太阳）影响陆地和水生生态系统在北美西部？最近已经描述了这一周期的潜在海洋学和气候相关影响，包括北美太平洋沿岸沿着的海面和大气影响，并建立了潜在的因果机制模型。我，在与他人合作，发现了强烈的暗示，在加拿大西部的几个水生和陆地生态系统的周期性波动，包括（一）代理少年红鲑鱼丰富的饲养湖，（二）氮浓度在沿海洪泛平原，（三）木炭浓度在内陆湖泊，（四）树木生长率在湖泊流域。我也发现了类似的周期性在一个专门的分析档案记录的增长亚高山冷杉和黑云杉在加拿大西北部。我打算通过以下方式来追求这一非凡的偶然发现：（i）为鲑鱼丰度的代理生成更进一步，更高分辨率和更长的时间序列，（ii）对存档的树木生长记录进行更严格和更广泛的评估，及（iii）从上述树木生长似乎最依赖的地区收集进一步证据-位于不列颠哥伦比亚省的西北角和邻近的育空地区。