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 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. 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.

对于存在复合种群（metapopulation）结构且世代重叠的生物类群，有效繁殖个体数（effective number of breeders, N̂_b）估算的时空推断尺度，以及此类估算能否用于预测世代有效种群大小（N_e），目前仍存在诸多不确定性。本研究针对溪鳟（Salvelinus fontinalis）开展长期监测，在其9个连续同龄群（cohort）中开展了一系列关于N̂_b估算时空推断尺度的检验工作。同时，我们还验证了一种新近提出的基于N̂_b估算世代有效种群大小的方法，并将其与另一种考虑年龄结构的有效种群大小（N̂_e）估算方法进行了对比。多项证据均表明，N̂_b的估算结果对应局域（亚种群）空间尺度与同龄群特异性的时间尺度。研究发现，至少需要4个连续的同龄群特异性N̂_b估算值，方可获得可靠的谐波均值N̂_b。基于同龄群特异性N̂_b推导得到的世代有效种群大小估算值，与另一种N̂_e估算方法的结果偏差介于7%~50%之间，提示两种方法的一致性存在种群特异性。本研究关于N̂_b估算时空推断尺度的结论，可广泛推广至诸多存在世代重叠与复合种群结构的类群，并为利用同龄群特异性N̂_b开展局域尺度遗传监测指明了极具潜力的研究方向。