Effects of soil conditions and growth stage
Correlations among trait canalization, integration and plasticity not only varied with greater densities, but such variations also change with soil conditions and growth stages. (Goswami et al. , 2015) showed an increase in correlation between fluctuating asymmetry and integration over time. But we found correlations among integration, canalization and plasticity increased over time in infertile soil, and decreased over time in fertile soil. As competition intensity may increase over time in infertile soil, and decrease over time in fertile soil (Wang et al. , 2017), soil condition and growth stage may also affect these correlations through modifying plant size and competition intensity. Additionally, since the positive correlations between integration and plasticity became stronger with higher densities in fertile soil only, it suggested plants in favorable conditions are more able to deal with the increase of density via coordination of trait plasticity and integration, whereas unfavorable conditions may attenuate this ability.