Simulated climate warming decreases fruit number but increases seed mass

• Published in: Global change biology 2023-02, Vol.29 (3), p.841-855
• Main Authors: Zi, Hongbiao, Jing, Xin, Liu, Anrong, Fan, Xiaomin, Chen, Si‐Chong, Wang, Hao, He, Jin‐Sheng
• Format: Article
• Language: English
• Subjects: Climate; Climate change; climate warming; Dominant species; Flowering; flowering phenology; Flowers; Fruit; Fruits; Geographical distribution; Global warming; Insects; Mass; Meta-analysis; Phylogenetics; Phylogeny; Plant reproduction; plant sexual reproduction; Plants; Plants (botany); Pollination; Pollination - physiology; Reproduction; Reproduction (biology); Reproductive effort; reproductive success; Seeds; Sexual reproduction
• ISSN: 1354-1013; 1365-2486
• DOI: 10.1111/gcb.16498

Climate warming is changing plant sexual reproduction, having consequences for species distribution and community dynamics. However, the magnitude and direction of plant reproductive efforts (e.g., number of flowers) and success (e.g., number and mass of fruits or seeds) in response to warming have not been well‐characterized. Here, we generated a global dataset of simulated warming experiments, consisting of 477 pairwise comparisons for 164 terrestrial species. We found evidence that warming overall decreased fruit number and increased seed mass, but little evidence that warming influenced flower number, fruit mass, or seed number. The warming effects on seed mass were regulated by the pollination type, and insect‐pollinated plants exhibited a stronger response to warming than wind‐pollinated plants. We found strong evidence that warming increased the mass of seeds for the nondominant species but no evidence of this for the dominant species. There was no evidence that phylogenetic relatedness explained the effects of warming on plant reproductive effort and success. In addition, the effects of warming on flowering onset negatively related to the responses in terms of the number of fruits and seeds to warming, revealing a cascading effect of plant reproductive development. These findings provide the first quantification of the response of terrestrial plant sexual reproduction to warming and suggest that plants may increase their fitness by producing heavier seeds under a warming climate. Using data on 164 species from 61 published studies, we present the first quantification on how experimental warming influences plant reproductive effort and success at a global scale. Warming overall decreased fruit number, increased seed mass, and did not influence flower number, fruit mass, or seed number. Furthermore, the positive relationship between warming effect sizes of seed mass and seed number did not support a trade‐off between offspring number and mass. These findings suggest that plants respond to warming climate by producing heavier seeds, which may bring a suite of ecological and physiological consequences in the subsequent life‐history stages.