Tall clonal grasses commonly display competitive advantages with nitrogen (N) enrichment. However, it is currently unknown whether their height is derived from the vegetative or reproductive module. Moreover, it is unclear whether the height of the vegetative or reproductive system regulates the probability of extinction and colonization, and determines species richness (frequency). In this study, the impacts on clonal grasses were studied in a field experiment employing two frequencies (twice a year or monthly) crossed with nine N addition rates in a temperate grassland. We found that the N addition decreased species frequency and increased extinction probability, but did not change the species colonization probability. A low frequency of N addition decreased species frequency and colonization probability, but increased extinction probability. Species reproductive height is the best index to predict the extinction probability of clonal grasses in N-enriched conditions relative to the vegetative height, average height, and species biomass. No significant relationships were detected between plant height and species colonization probability. The low frequency of N addition may overestimate the negative effect from N deposition on clonal grass diversity, suggesting that a higher frequency of N addition is more suitable in assessing the ecological effects of N deposition. Moreover, this study illustrates that reproductive height, not the vegetative height, was associated with the clonal species extinction probability under N-enriched environment.

Plant biochemical reactions are dependent on the combined action of multiple elements. However, it remains unclear how these elements co-vary to adapt to environmental change. Here, we propose a novel concept of the multi-element network (MEN) including the mutual effects between elements to more effectively explore the alterations in response to long-term nitrogen (N) deposition simulations. MENs were constructed with 18 elements and were species specific. Macroelements were more stable, but microelements were more susceptible to N deposition. Interestingly, higher MEN plasticity determined increased relative aboveground biomass (species importance) for different species in one functional group under simulated N deposition. Furthermore, the association between MEN plasticity and species importance was consistently verified along a dry–wet transect. In summary, MENs provide a novel approach for exploring the adaptation strategies of plants and to better predict community composition under altering nutrient availability or environmental stress associated with future global climate change.