The incredible vulnerability that reproduction poses for plant species in a warming world

Temperatures are rising globally and threatening the persistence of natural plant populations. Elevated temperatures disrupt gametogenesis, fertilization, and seed filling, often at lower thresholds than those affecting photosynthesis, growth, or survival. While crop scientists have found that key reproductive stages are particularly vulnerable to heat stress across plant systems, ecological and evolutionary studies have largely focused on other fitness metrics to estimate populations' resilience to warming. We advocate for integrating pollen, ovule, and seed filling developmental metrics into ecological and evolutionary studies to improve predictions of plant population dynamics under future climates. Such studies will offer not only a better understanding of how natural populations will respond to increasing temperature stress but also are likely to reveal novel mechanistic insights that can be utilized to improve crop resilience in a warming world.