Department of Biological, Geological and Environmental Sciences, University of Catania, Via Antonino Longo 19, 95125, Catania, Italy.
Sci Rep. 2024 Sep 27;14(1):22235. doi: 10.1038/s41598-024-73021-7.
Poterium spinosum L. is a key plant species forming typical shrub communities, distributed across the Mediterranean eastern coasts. The conservation of P. spinosum is thus of the utmost importance, especially due to the ever-increasing environmental pressures like climate changes and habitat fragmentation. This study, in particular, investigated for the first time the germination variability of P. spinosum at intrapopulation level, by analysing the germination behavior of five different subpopulations growing along the coasts of Sicily. For a more exhaustive picture of the main drivers of biodiversity loss affecting the distributional area of P. spinosum, the trends of climate and land-cover changes were also studied over the periods 1931-2020 and 1958-2018, respectively. The results found significant intrapopulation variability in P. spinosum, whose germination parameters showed that fruits and seeds from distinct subpopulations respond differently to diverse temperatures. Seeds showed generally higher values of final germination percentage (FGP) compared to fruits, and at higher temperatures: the highest FGP in seeds was 70% at 20 °C, whereas in fruits was 58.2% at 15 °C. The environmental threats showed worrying trends across the study area: during 1931-2020, the average temperature increased by 1.5 °C, whereas the average rainfall declined from 710 to 650 mm. Similarly, in the period 1958-2018, the analysis of the CORINE land-cover changes showed a highly fragmented agricultural landscape, where natural areas were reduced to 2.5-5.0%. Germination variability at intrapopulation level should be considered as a fundamental adaptation strategy, which can increase the reproductive success of P. spinosum under climate and land-cover changes.
刺芹（Poterium spinosum L.）是一种关键的植物物种，形成典型的灌木群落，分布在地中海东部海岸。因此，刺芹的保护至关重要，尤其是由于气候变化和生境破碎化等环境压力不断增加。本研究首次在种群内水平上研究了刺芹的发芽变异性，分析了生长在地中海西西里岛海岸的五个不同亚种群的发芽行为。为了更全面地了解影响刺芹分布区生物多样性丧失的主要驱动因素，还分别研究了 1931-2020 年和 1958-2018 年期间的气候和土地覆盖变化趋势。研究结果发现，刺芹种群内存在显著的变异性，其发芽参数表明，来自不同亚种群的果实和种子对不同温度的反应不同。种子的最终发芽率（FGP）普遍高于果实，且在较高温度下：种子的最高 FGP 为 20°C 时的 70%，而果实为 15°C 时的 58.2%。研究区域内的环境威胁呈现出令人担忧的趋势：在 1931-2020 年期间，平均温度上升了 1.5°C，而平均降雨量从 710 毫米下降到 650 毫米。同样，在 1958-2018 年期间，对 CORINE 土地覆盖变化的分析显示，农业景观高度破碎化，自然区域减少到 2.5-5.0%。种群内的发芽变异性应被视为一种基本的适应策略，可以提高刺芹在气候和土地覆盖变化下的繁殖成功率。
