Similar to species richness, genotypic richness of plants plays a pivotal role in the structure and function of ecosystems. While the contribution of intraspecific variability to ecosystem function has been well-established, the mechanisms underlying the effect of genotypic richness on nitrogen (N) uptake patten remain poorly understood. We established experimental populations consisting of 1, 4, or 8 genotypes of the clonal plant Hydrocotyle verticillata in microcosms and conducted ¹⁵N-labeling to quantify plant N uptake. NH₄⁺-N uptake rate of the populations with 8 genotypes was significantly higher than that of the populations with 1- and 4-genotypes, while genotypic richness did not influence NO₃⁻-N uptake rate. Increasing genotypic richness also enhanced NH₄⁺-N uptake preference and reduced NO₃⁻-N uptake preference. Additionally, increasing genotypic richness facilitated the transformation of the soil nitrogen pool, resulting in a reduction of total soil N content and an increase in soil NH₄⁺-N, thereby causing a shift in population N uptake preference. Our findings highlight the importance of genotypic richness on both N uptake and N form preference of plant populations. Such intraspecific variability in N uptake and N form preference may further influence population dynamics and ecosystem function.

与物种丰富度类似，植物的基因型丰富度在生态系统的结构和功能中起着关键作用。虽然种内变异对生态系统功能的贡献已经明确，但基因型丰富度对氮（N）吸收模式影响的机制仍然知之甚少。我们在微观世界中建立了由克隆植物 Hydrocotyle verticillata 的 1、4 或 8 个基因型组成的实验群体，并进行 ¹⁵ N 标记以量化植物的氮吸收。 NH ₄ ⁺ -8基因型群体的氮吸收率显着高于1基因型和4基因型群体，而基因型丰富度对NO的影响不显着 ₃ ⁻ -N 吸收率。增加基因型丰富度还增强了 NH ₄ ⁺ -N 吸收偏好并降低了 NO ₃ ⁻ -N 吸收偏好。此外，基因型丰富度的增加促进了土壤氮库的转变，导致土壤总氮含量减少，土壤NH ₄ ⁺ -N增加，从而引起土壤氮素转移。种群对氮的吸收偏好。我们的研究结果强调了基因型丰富度对植物种群氮吸收和氮形态偏好的重要性。这种氮吸收和氮形态偏好的种内变异可能会进一步影响种群动态和生态系统功能。