Ningna Lu, Meng Hou, Yan Ma, Opedal Øystein H, Zhigang Zhao
School of Life Science North-West Normal University Lanzhou China.
College of Ecology Lanzhou University Lanzhou China.
Ecol Evol. 2025 Jun 14;15(6):e71592. doi: 10.1002/ece3.71592. eCollection 2025 Jun.
Nutrient enrichment is an increasingly important consequence of anthropogenic activities. Nutrient enrichment can alter the composition, diversity, and functioning of terrestrial plant communities, yet its effect on evolutionary processes in plant populations has been less well studied. To understand the evolutionary consequence of long-term soil nutrient enrichment, we examine the effects of nutrient addition (N or P) on plant traits, female reproductive success, and pattern of phenotypic selection in the annual plant M. in an alpine meadow on the Tibetan Plateau. Nutrient addition generally increased plant height and reduced tube length and nectar production per flower. Surprisingly, the effects of N and P addition on seed number per plant were reversed between years. Despite variation in traits, mean fitness, and opportunity for selection among nutrient treatments, patterns of selection changed only for nectar production, where we detected N-mediated selection favoring greater nectar production. This study suggests that nutrient enrichment can alter patterns of phenotypic selection, potentially influencing the evolution of floral traits even if pollinators play a limited role in selection.
养分富集是人为活动日益重要的一个后果。养分富集能够改变陆地植物群落的组成、多样性和功能，然而其对植物种群进化过程的影响却较少得到充分研究。为了了解长期土壤养分富集的进化后果，我们研究了在青藏高原一个高山草甸中，添加养分（氮或磷）对一年生植物米口袋的植物性状、雌性繁殖成功率及表型选择模式的影响。添加养分通常会增加株高，并缩短花管长度及减少单花的花蜜分泌量。令人惊讶的是，添加氮和磷对单株种子数量的影响在不同年份出现了反转。尽管在不同养分处理之间，性状、平均适合度及选择机会存在差异，但选择模式仅在花蜜分泌量方面发生了变化，我们检测到氮介导的选择有利于更高的花蜜分泌量。这项研究表明，养分富集能够改变表型选择模式，即使传粉者在选择中作用有限，也可能影响花部性状的进化。
