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

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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.