Bai Lu, Han Guodong, Jiang Lin, Crowther Thomas W, Zohner Constantin M, Yu Kailiang, Xu Zhuwen, Wang Zhongwu, Wu Qian, Zhu Yi, Tang Jinglei, Ren Haiyan
Key Laboratory of Grassland Resources of the Ministry of Education, College of Grassland Science, Inner Mongolia Agricultural University, Hohhot, China.
School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA.
Ecology. 2025 Jun;106(6):e70139. doi: 10.1002/ecy.70139.
Climate change is known to affect plant phenology. Yet, the sensitivity of flowering phenology in dryland regions to climate change, and the potential implications for community composition, remain largely unexplored. Here, we used an 18-year field experiment to investigate the effects of climate warming and nitrogen addition on flowering phenology of four C plant species and two C plant species, and the cascading effects on the relative abundance of C and C plants in a desert steppe. Across the past 10 years of the experiment (2013-2022), we found that warming had a greater effect on phenological shifts in C than in C plants. Warming significantly advanced the flowering time of C plants by 4.3 ± 0.1 days and of C plants by 2.8 ± 0.1 days, respectively. Warming also reduced the duration of flowering by 1.8 ± 0.1 days for C plants but had no effect on C plants, and decreased the dominance of C plants compared to C plants. Nitrogen addition extended the duration of flowering of C plants by 3.4 ± 0.2 days and increased their relative dominance, while decreasing the dominance of C plants. Structural equation models revealed that these phenological responses were largely driven by soil temperature and soil water availability. Our results demonstrate that the different phenological responses of C and C plants contribute to shifts in dominance between these plant types in temperate dryland ecosystems under global changes.
众所周知，气候变化会影响植物物候。然而，旱地地区开花物候对气候变化的敏感性以及对群落组成的潜在影响，在很大程度上仍未得到探索。在此，我们利用一项为期18年的田间试验，研究了气候变暖和添加氮素对4种C植物物种和2种C植物物种开花物候的影响，以及对荒漠草原中C植物和C植物相对丰度的级联效应。在过去10年的试验期（2013 - 2022年）内，我们发现变暖对C植物物候变化的影响比对C植物的影响更大。变暖使C植物的开花时间分别显著提前了4.3±0.1天，使C植物的开花时间提前了2.8±0.1天。变暖还使C植物的开花持续时间缩短了1.8±0.1天，但对C植物没有影响，并且与C植物相比降低了C植物的优势度。添加氮素使C植物的开花持续时间延长了3.4±0.2天，并增加了它们的相对优势度，同时降低了C植物的优势度。结构方程模型表明，这些物候响应主要由土壤温度和土壤水分有效性驱动。我们的结果表明，在全球变化下，温带旱地生态系统中C植物和C植物不同的物候响应导致了这些植物类型之间优势度的变化。
