Data from: Harvested populations are more variable only in more variable environments

The interaction between environmental variation and population dynamics is of major importance, particularly for managed and economically important species, and especially given contemporary changes in climate variability. Recent analyses of exploited animal populations contested whether exploitation or environmental variation has the greatest influence on the stability of population dynamics, with consequences for variation in yield and extinction risk. Theoretical studies however have shown that harvesting can increase or decrease population variability depending on environmental variation, and requested controlled empirical studies to test predictions. Here, we use an invertebrate model species in experimental microcosms to explore the interaction between selective harvesting and environmental variation in food availability in affecting the variability of stage-structured animal populations over 20 generations. In a constant food environment, harvesting adults had negligible impact on population variability or population size, but in the variable food environments, harvesting adults increased population variability and reduced its size. The impact of harvesting on population variability differed between proportional and threshold harvesting, between randomly and periodically varying environments, and at different points of the time series. Our study suggests that predicting the responses to selective harvesting is sensitive to the demographic structures and processes that emerge in environments with different patterns of environmental variation.环境变异与种群动态之间的相互作用具有重要研究价值，尤其针对受管理物种及具有经济重要性的物种，在当前气候变率发生改变的背景下尤为如此。针对被开发利用的动物种群的近期研究引发了争议：究竟是开发活动还是环境变异对种群动态稳定性的影响更大，这一问题进而会影响产量波动与灭绝风险。不过，理论研究表明，捕捞对种群变异的影响可升高或降低种群变异程度，具体取决于环境变异情况，且学界呼吁开展受控实证研究以验证相关预测。本研究利用实验微宇宙中的无脊椎动物模式物种，探究选择性捕捞与食物可获得性的环境变异之间的相互作用，及其在20代时间尺度上对阶段结构化动物种群变异的影响。在食物环境恒定的条件下，捕捞成体对种群变异或种群规模的影响可忽略不计；但在食物环境波动的条件下，捕捞成体会加剧种群变异并降低种群规模。捕捞对种群变异的影响因捕捞方式（比例捕捞与阈值捕捞）、环境波动类型（随机波动与周期性波动）以及时间序列的不同阶段而异。本研究表明，对选择性捕捞响应的预测，会因不同环境变异模式下所形成的种群统计结构与过程而异。