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.环境变化与种群动态之间的相互作用至关重要，尤其针对受管理及具有重要经济价值的物种，在当代气候波动加剧的背景下这一议题尤为关键。近期针对被开发利用的动物种群的相关分析，就开发活动与环境变化何者对种群动态稳定性的影响更大这一问题引发了争议，其结论会对产量波动与灭绝风险的变化产生影响。不过，现有理论研究表明，捕捞对种群变异性的影响会随环境变化呈现增强或减弱的效果，并呼吁开展可控的实证研究以验证相关预测。本研究借助实验微宇宙中的无脊椎动物模式物种，探究了20代周期内，选择性捕捞与食物可获得性的环境变化之间的交互作用，及其对阶段结构化动物种群变异性的影响。在恒定食物环境中，捕捞成体对种群变异性或种群规模几乎无显著影响；但在波动食物环境中，捕捞成体会加剧种群变异性并降低种群规模。捕捞对种群变异性的影响，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存在差异。本研究表明，对选择性捕捞响应的预测，会因不同环境变化模式下所形成的种群统计结构与过程而异。