Data from: A model-derived short-term estimation method of effective size for small populations with overlapping generations

1. If not actively managed, small and isolated populations lose their genetic variability and the inbreeding rate increases. Combined, these factors limit the ability of populations to adapt to environmental changes, increasing their risk of extinction. The effective population size (Ne) is proportional to the loss of genetic diversity and therefore of considerable conservation relevance. However, estimators of Ne that account for demographic parameters in species with overlapping generations require sampling of populations across generations, which is often not feasible in long-lived species. 2. We created an individual-based model that allows calculation of Ne based on demographic parameters that can be obtained in a time period much shorter than a generation. It can be adapted to every life-history parameter combination. The model is freely available as an R-package NEff. 3. The model was first used in a simulation experiment observing changes in Ne in response to different degrees of generational overlap. Results showed that increased generational overlap slowed annual rates of heterozygosity loss, resulting in higher annual effective sizes (Ny) but decreased Ne per generation. Adding the effect of different recruitment rates only affected Ne for populations with low generational overlap. 4. The model was further tested using real population data of the Australian arboreal gecko Gehyra variegata. Simulation results were compared to genetic analyses and matched estimates of the real population very well. 5. Unlike other estimation methods of Ne, NEff neither requires long time series of population monitoring nor genetic analyses of changes in gene frequencies. Thus, it seems to be the first method for calculating Ne within short time periods and comparably low costs facilitating the use of Ne in applied conservation and management.

1. 若未进行主动管理，小型孤立种群会丧失遗传变异，且近交速率上升。上述因素共同限制了种群适应环境变化的能力，进而提升其灭绝风险。有效种群大小（effective population size, Ne）与遗传多样性丧失呈正比，因此在保护生物学中具有重要意义。然而，针对世代重叠物种的种群动态参数进行校正的Ne估计方法，需要跨世代对种群进行采样，这对于长寿命物种而言通常难以实现。
2. 本研究构建了一种基于个体的模型，可基于远短于世代时长的周期内即可获取的种群动态参数计算Ne。该模型可适配任意生命史参数组合，且以R包（R-package）NEff的形式免费公开。
3. 该模型首先被应用于模拟实验，以观测不同世代重叠程度下Ne的变化。结果显示，世代重叠程度的提升会减缓年度杂合度丧失速率，使得年度有效种群规模（Ny）升高，但每世代的Ne却有所降低。引入不同种群补充率的影响后，仅会对低世代重叠种群的Ne产生作用。
4. 本研究进一步利用澳大利亚树栖壁虎多色鳞虎（Gehyra variegata）的真实种群数据对模型进行了测试。将模拟结果与遗传分析结果进行比对后发现，其与真实种群的估计值匹配度极佳。
5. 与其他Ne估计方法不同，NEff既无需长时间的种群监测序列，也无需针对基因频率变化开展遗传分析。因此，该方法似乎是首个可在短周期内以相对较低成本计算Ne的工具，能够推动Ne在实际保护与管理工作中的应用。