The relative competition intensity (RCI) of different functional traits
was calculated by using following equation
(Gruntman et al., 2014,
He et al., 2012) between
WT and WC under different nitrogen and
water treatments.
\begin{equation}
RCI=\frac{A_{\text{mix}}-A_{\text{mono}}}{A_{\text{mix}}+A_{\text{mono}}}\nonumber \\
\end{equation}Where Amix is the trait value of either
WT or WC in the mixed culture, while
Amono is the trait value of either WT or
WC in the monoculture. RCI values range from -1 to 1.
Negative values indicate competition; positive values indicate
facilitation; 0 value means
neither competitive nor facilitative interactions.
The plasticity index (PI) of functional traits was
calculated by using equation (Funk, 2008,
Lamarque et al., 2013) to determine the
range of phenotypic plasticity of different functional traits of
WT and WC under different nitrogen and
water treatments within mixed culture.
\begin{equation}
P_{I}=\frac{Maximum\ value-Minimum\ value}{\text{Maximum\ value}}\nonumber \\
\end{equation}where maximum and minimum value are the maximum and minimum value of one
functional trait of WT or WC grown in
mixed culture under each treatment. The value of PIranges from 0 to 1, where one represented the highest
PI.