羊草种子生产、大小、萌发能力和幼苗生长对母体增温环境的响应

he effects of global climate warming on seed production have been well documented in high-latitude or arctic regions, but investigation of the overall impact of warming on seed production has largely been neglected in temperate semi-arid regions, especially seed mass frequency distribution, germinability, and subsequent seedling growth. This study use Leymus chinensis, a dominant perennial grass widely distributed in the eastern regions of the Eurasia grassland zone as a model to investigate the effect of warming on the above factors, providing new information on new plant population establishment and how the existing population is maintained in this region. There was a significant positive response in floret number and seed number per plant to warming. However, there were negative responses to warming in terms of the flowering plant number and seed number per unit area. Warming significantly decreased the proportion of light seeds, increased the proportion of heavy seeds, and led to a significant increase in the thousand seeds weight. Germination success and rate, together with the root:shoot ratio of light seeds was significantly reduced by warming, in contrast to the heavy seeds which did not seem to be affected by elevated temperatures. Finally, warming reduced the potential germinated seed number per square meter. Synthesis analysis indicated that warming had different effects on the seed production process in semi-arid regions depending on the season. There was a positive effect in high precipitation summers and cold springs, and a negative effect in low precipitation autumns. The reduction in the germinability of light seeds and the seed germination potential with increased temperature has implications for new population establishment. Furthermore, existing population maintenance that depends on the seeds is likely to be constrained by global warming and will have an effect on plant population dynamics in the eastern regions of the Eurasia grassland zone.