Grazing and light modify Silene latifolia responses to nutrients and future climate

biomass in future climatic conditions compared to ambient conditions, however, only in the absence of grazing (significant E x C interaction, Table 1, Fig 1B). Grazing also showed a strong main effect and reduced plant height by 83% (* 39 ± 3.6 cm) and total aboveground biomass by 95% compared to fenced plots (Table 1, Fig 1A and 1B). The responses of Silene foliar traits to nutrient and light additions, and future climate Foliar leaf traits inside fences responded to resources additions. C:N ratio increased (i.e., the relative C content increased) with light addition in fertilized plots, while light addition had no effect on it in unfertilized plots (significant F × L interaction, Table 2, Fig 2A). Furthermore, SLA increased with light addition, but only under ambient climate (significant C × L interac- tion, Table 2). In addition, this effect was greater in fertilized plots although the interaction with fertilization was not significant (Fig 2B and Table 2). Light addition alone increased SLA Table 2. Main and interactive treatment effects on Silene foliar traits. SLA_fenced Foliar CN_fenceda df F p df F p Fertilization 1,8 0.23 0.644 1,11 5.84 0.034 Climate 1,7 < .1 0.805 1,7 1.75 0.225 Light 1,11 7.01 0.023 1,16 < .1 0.918 F x C 1,9 2.22 0.169 1,11 0.35 0.567 F x L 1,10 < .1 0.861 1,16 5.96 0.027 C x L 1,11 5.56 0.038 1,16 1.35 0.262 F x C x L 1,11 1.71 0.218 1,16 0.90 0.357

Results of linear mixed effect models testing the effects of fertilization, climate and light addition on Silene leaf traits (SLA and foliar C:N). Significant results (p < .05) are printed in bold, marginally significant results (p < .1) are printed in italic. a data are log transformed. https://doi.org/10.1371/journal.pone.0276789.t002 Fig 2. Treatment effects on Silene foliar traits. Foliar C:N (a, n = 36) and SLA (b, n = 32) responses of Silene latifolia to combinations of fertilization, ambient and future climate and light addition. The data are from inside the fences and represent means ± SE. Note, that there are less than 40 samples per trait, because some transplants did not have healthy and undamaged leaves. https://doi.org/10.1371/journal.pone.0276789.g002 PLOS ONE Transplant performance and trait responses to abiotic and biotic changes PLOS ONE | https://doi.org/10.1371/journal.pone.0276789 November 8, 2022 8 / 16