Zhou Zhenxing, Feng Hanlin, Ma Gaigai, Ru Jingyi, Wang Haidao, Feng Jiayin, Wan Shiqiang
School of Life Sciences, Institute of Life Science and Green Development, Hebei University, Baoding, Hebei 071002, China.
School of Life Sciences, Henan University, Kaifeng, Henan 475004, China.
Ann Bot. 2025 Feb 8;135(1-2):211-222. doi: 10.1093/aob/mcae138.
Changing precipitation regimes can influence terrestrial plants and ecosystems. However, plant phenological responses to changing temporal patterns of precipitation and the underlying mechanisms are largely unclear. This study was conducted to explore the effects of seasonal precipitation redistribution on plant reproductive phenology in a temperate steppe.
A field experiment was undertaken with control (C), advanced (AP) and delayed (DP) growing-season precipitation peaks and the combination of AP and DP (ADP). Seven dominant plant species were selected and divided into two functional groups (early- vs. middle-flowering species, shallow- vs. deep-rooted species) to monitor reproductive phenology, including budding, flowering and fruiting dates and the reproductive duration for four growing seasons, 2015-2017 and 2022.
The AP, but not DP treatment advanced the phenological (i.e. budding, flowering and fruiting) dates and lengthened the reproductive duration across the four growing seasons and seven monitored species. In addition, the phenological responses showed divergent patterns among different plant functional groups, which could be attributed to shifts in soil moisture and its variability in different months and soil depths. Moreover, species with lengthened reproductive duration increased phenological overlap with other species, which could have a negative impact on their dominance under the AP treatment.
Our findings reveal that changing precipitation seasonality could have considerable impacts on plant phenology by affecting soil water availability and variability. Incorporating these two factors simultaneously in the phenology models will help us to understand the response of plant phenology under intensified changing precipitation scenarios. In addition, the observations of decreased dominance for the species with lengthened reproductive duration suggest that changing reproductive phenology can have a potential to affect community composition in grasslands under global change.
降水格局的变化会影响陆生植物和生态系统。然而，植物物候对降水时间模式变化的响应及其潜在机制在很大程度上尚不清楚。本研究旨在探讨季节性降水再分配对温带草原植物繁殖物候的影响。
进行了一项田间试验，设置了生长季降水峰值提前（AP）、延迟（DP）以及二者组合（ADP）的处理，并设置了对照（C）。选择了七种优势植物物种，分为两个功能组（早花与中花物种、浅根与深根物种），以监测2015 - 2017年和2022年四个生长季的繁殖物候，包括出芽、开花和结果日期以及繁殖持续时间。
AP处理而非DP处理提前了四个生长季和七种监测物种的物候（即出芽、开花和结果）日期，并延长了繁殖持续时间。此外，物候响应在不同植物功能组之间呈现出不同模式，这可归因于不同月份和土壤深度的土壤水分及其变异性的变化。而且，繁殖持续时间延长的物种与其他物种的物候重叠增加，这可能对其在AP处理下的优势度产生负面影响。
我们的研究结果表明，降水季节性变化可能通过影响土壤水分有效性及其变异性对植物物候产生重大影响。在物候模型中同时纳入这两个因素将有助于我们理解在降水变化加剧的情况下植物物候的响应。此外，对繁殖持续时间延长的物种优势度降低的观察表明，繁殖物候变化可能会在全球变化下影响草原群落组成。
