Data from: Keeping things local: subpopulation Nb and Ne in a stream network with partial barriers to fish migration

For organisms with overlapping generations that occur in metapopulations, uncertainty remains regarding the spatio-temporal scale of inference of estimates of the effective number of breeders (N^b)and whether these estimates can be used to predict generational Ne. We conducted a series of tests of the spatio-temporal scale of inference of estimates of Nb in nine consecutive cohorts within a long-term study of brook trout (Salvelinus fontinalis). We also tested a recently developed approach to estimate generational Ne from N^b and compared this to an alternative approach for estimating N^e that also accounts for age structure. Multiple lines of evidence were consistent with N^b corresponding to the local (subpopulation) spatial scale and the cohort-specific temporal scale. We found that at least four consecutive cohort-specific estimates of N^b were necessary to obtain reliable estimates of harmonic mean N^b for a subpopulation. Generational N^e derived from cohort-specific N^b were within 7 - 50% of an alternative approach to obtain, N^e suggesting some population-specificity for concordance between approaches. Our results regarding the spatio-temporal scale of inference for Nb should apply broadly to many taxa that exhibit overlapping generations and metapopulation structure and point to promising avenues for using cohort-specific N^b for local-scale genetic monitoring.对于存在重叠世代且具有集合种群（metapopulations）结构的生物，有效繁殖个体数（effective number of breeders，N^b）估计值的推断时空尺度，以及此类估计值能否用于预测世代有效种群大小（generational N^e），仍存在不确定性。我们针对溪鳟（Salvelinus fontinalis）的长期研究中的9个连续同龄群（cohort），开展了一系列关于N^b估计值推断时空尺度的检验。同时，我们还测试了一种新近开发的、基于N^b估计世代有效种群大小的方法，并将其与另一种同时考虑年龄结构（age structure）的N^e估计方法进行了比较。多项证据均表明，N^b对应局域亚种群（subpopulation）空间尺度与同龄群特异性的时间尺度。我们发现，若要获得某亚种群的N^b调和均值（harmonic mean）估计值，至少需要4个连续的同龄群特异性N^b估计结果。基于同龄群特异性N^b推导得到的世代N^e，与另一种N^e估计方法的结果相差7%至50%，这提示不同种群间的方法一致性存在种群特异性。本研究关于N^b推断时空尺度的结论，可广泛适用于诸多具有重叠世代与集合种群结构的生物类群，并为利用同龄群特异性N^b开展局域尺度遗传监测（genetic monitoring）指明了颇具前景的方向。