Global parameters and variables for the model.

Invasive pests and pathogens are a major driver of biodiversity loss. Some rare species may persist through rapid evolution to tolerate or escape new threats, but representing the underlying ecological and evolutionary processes at the appropriate scale is analytically and computationally challenging. Tillandsia utriculata has been classified as endangered in Florida where its population has decreased significantly due to predation by the invasive Mexican weevil Metamasius callizona. Adult female weevils deposit their eggs in leaves of epiphytic bromeliads, preferentially ovipositing in the largest rosettes. Once the eggs hatch, the larvae consume the core of the rosette, often leading to pre-reproductive death. During the past three decades of predation, the T. utriculata population has shifted to initiating the production of inflorescences (to commence its single attempt at sexual reproduction) at smaller rosette sizes. Importantly, the rosette size at induction is correlated with the number of seeds produced. We have constructed an agent-based model to simulate the dynamics of a Florida T. utriculata population over many generations where the minimum rosettes size required to initiate inflorescence production (minimum size of induction or MSI), is an inherited trait. We use the model to explore how predation may have shifted the population’s genetic composition and the impact this has on population viability. Our results show that larger germination rates are required for population viability when weevils are present. Parameter uncertainty analysis revealed that in the presence of weevil predation, only a population with a very high germination rate and a short period of predation would sustain its population for 100 years with sizes similar to simulations without weevil predation. Furthermore, uncertainty analysis showed that the mean MSI of the population decreased over a 100-year period without weevil predation, and this trend was exacerbated by the presence of weevil predation.外来入侵害虫与病原生物是生物多样性丧失的主要驱动因素。部分珍稀物种可通过快速演化耐受或规避新型威胁，但在适宜尺度下还原其内在生态与演化过程，在分析与计算层面均颇具挑战。瓶状铁兰（Tillandsia utriculata）在佛罗里达州被列为濒危物种，该州内其种群因外来入侵的墨西哥象鼻虫（Metamasius callizona）的取食而大幅下降。雌性成虫将卵产于附生凤梨科植物的叶片中，且优先选择最大的莲座株丛产卵。卵孵化后，幼虫取食莲座株丛的核心组织，常导致植株在繁殖前死亡。在过去三十年的象鼻虫取食压力下，瓶状铁兰种群已出现适应性转变：其开始抽生花序（完成单次有性生殖过程）的莲座株丛尺寸较此前更小。尤为关键的是，花序诱导时的莲座株丛尺寸与种子产量呈正相关。我们构建了基于智能体的模型（agent-based model），用以模拟多世代下佛罗里达州瓶状铁兰种群的动态变化：其中启动花序抽生所需的最小莲座株丛尺寸（诱导最小尺寸，MSI）为可遗传性状。我们借助该模型探究了象鼻虫取食压力如何改变种群的遗传组成，以及该变化对种群生存力的影响。研究结果表明，当存在象鼻虫取食压力时，种群维持生存力需要更高的种子萌发率。参数不确定性分析结果显示，在存在象鼻虫取食的情境下，仅当种群具备极高的种子萌发率且取食持续时长较短时，其种群规模才能在100年内维持与无象鼻虫取食情景下的模拟结果相近的水平。此外，不确定性分析结果表明，在无象鼻虫取食的情景下，种群的平均诱导最小尺寸（MSI）会在100年间呈下降趋势，而象鼻虫取食压力会进一步加剧这一趋势。