Intraspecific Variation in Functional Traits of Medicago sativa Determine the Effect of Plant Diversity and Nitrogen Addition on Flowering Phenology in a One-Year Common Garden Experiment

Nitrogen deposition and biodiversity alter plant flowering phenology through abiotic factors functional traits. However, few studies have considered their combined effects on phenology. A common garden experiment with two nitrogen addition levels (0 6 g N m?2 year?1) five species richness (1, 2, 4, 6, 8) was established. We assessed the of three phenological events Medicago sativa L. via changes in traits, soil nutrients, moisture temperature. The first day delayed, last advanced, duration shortened after addition. Meanwhile, along gradients, an average 0.64 0.95 days change per increase, respectively. Importantly, it observed that affected mainly nutrient acquisition traits (i.e., leaf carbon/nitrogen ratio). Our findings illustrate non-negligible intraspecific variation highlight importance including models to improve predictions response loss.