Ecological memory (EM) recognizes the importance of previous stress encounters in promoting community tolerance and thereby enhances ecosystem stability, provided that gained tolerances are preserved during non-stress periods. Drawing from this concept, we hypothesized that the recruitment of tolerant species can be facilitated by imposing an initial sorting process (conditioning) during the early stages of community assembly, which should result in higher production (biomass development and photosynthetic efficiency) and stable community composition. To test this, phytoplankton resting stages were germinated from lake sediments originating from two catchments that differed in contamination history: one impacted by long-term herbicides and pesticides exposures (historically contaminated lake) from an agricultural catchment compared to a low-impacted one (near-pristine lake) from a forested catchment. Conditioning was achieved by adding an herbicide (Isoproturon, which was commonly used in the catchment of the historically contaminated lake) during germination. Afterward, the communities obtained from germination were exposed to an increasing gradient of Isoproturon. As hypothesized, upon conditioning, the phytoplankton assemblages from the historically contaminated lake were able to rapidly restore photosynthetic efficiency (p > 0.01) and became structurally (community composition) more resistant to Isoproturon. The communities of the near-pristine lake did not yield these positive effects regardless of conditioning, supporting that EM was a unique attribute of the historically stressed ecosystem. Moreover, assemblages that displayed higher structural resistance concurrently yielded lower biomass, indicating that benefits of EM in increasing structural stability may trade-off with production. Our results clearly indicate that EM can foster ecosystem stability to a recurring stressor.

生态记忆（EM）认识到先前遇到的压力对于提高社区的耐受性具有重要意义，因此可以提高生态系统的稳定性，前提是在非压力时期内保持所获得的耐受性即可。从这个概念出发，我们假设可以通过在社区集会的早期阶段进行初始分选过程（调节）来促进耐性物种的募集，这应该导致更高的产量（生物量发育和光合效率）和稳定的社区组成。为了测试这一点，浮游植物的静息期是从湖泊中沉积物发芽的，该沉积物来自两个受污染历史不同的流域：相比之下，受农业流域长期除草剂和杀虫剂暴露（历史上受污染的湖泊）的影响要比受到森林流域的影响较小（近原始湖）的受到的影响更大。通过在发芽过程中添加除草剂（异丙草隆，常用于受历史污染的湖的集水区）来进行调理。此后，从发芽获得的群落暴露于异丙隆的递增梯度下。根据假设，经过条件处理，来自历史受污染湖泊的浮游植物组合能够迅速恢复光合作用效率（此后，从发芽获得的群落暴露于异丙隆的递增梯度下。根据假设，经过条件处理，来自历史受污染湖泊的浮游植物组合能够迅速恢复光合作用效率（此后，从发芽获得的群落暴露于异丙隆的递增梯度下。根据假设，经过条件处理，来自历史受污染湖泊的浮游植物组合能够迅速恢复光合作用效率（p  > 0.01），并且在结构上（社区组成）对异丙隆具有更强的抵抗力。不论条件如何，近原始湖泊的社区都没有产生这些积极的影响，这支持了EM是历史上受到压力的生态系统的独特属性。此外，显示较高结构抗性的组合物同时产生较低的生物量，这表明EM在增加结构稳定性方面的优势可能会与生产权衡。我们的结果清楚地表明，EM可以促进生态系统的稳定，以应对反复出现的压力。