Fig. 6.

Effects of N addition and annual mowing on species richness, species asynchrony, and ecosystem stability. The final structural equation modelling (SEM) fitted the data well: χ² = 0·293, d.f. = 2, P = 0·920; root square mean errors of approximation <0·001; AIC = 26·293. Numbers adjacent to arrows are standardized path coefficients, and width of the arrows indicates the strength of the relationship. Dashed and solid arrows indicate P > 0·1 and P < 0·01, respectively. Black and red arrows indicate positive and negative relationship, respectively. Percentages close to endogenous variables indicate the variance explained by the model (R²). The SEM revealed that annual mowing exacerbated the negative effect of N enrichment on ecosystem stability through a decrease in species asynchrony.