Global Environmental Change Shifts Ecological Stoichiometry Coupling Between Plant and Soil in Early-Stage Invasions

Extensive research has been conducted on the ecological stoichiometry of plants and soils. However, the relationship between plants and soil stoichiometry under the global environmental change is not fully understood. Specifically, the impact of this relationship on alien plant invasion is even less well-known. We conducted a controlled greenhouse experiment to quantify the ecological stoichiometry responses of both the plant and the soil systems under three different temperature and nitrogen treatment levels. We employed a randomized experimental design to examine the coupling mechanism between ecological stoichiometry and environmental changes during early-stage invasions. The results indicated that the warming and nitrogen addition treatments had a significant impact on the concentrations of plant organic carbon (C) and total N, but not on the soil C and N concentrations. This is likely due to the strong stoichiometric homeostasis of soil microorganisms. The linear regression analysis between the plant and the soil traits suggested a tight coupling between the plant and the soil system under the control treatments, with nutrient equilibrium during the early-stage invasions. However, the linear regression analysis also revealed that environmental changes, such as warming and nitrogen deposition, disrupted the stoichiometric coupling between the plant and soil, exacerbating the possibility of invasion. Our results demonstrate that the persistent changes in regional nutrient and temperature levels may exacerbate the likelihood of invasion by disrupting the ecological stoichiometric coupling between plants and soils. The close relationship between plant, soil, and environment in our study showed that nitrogen deposition had greater explanatory power than warming for changes in plant growth and stoichiometry in both plant and soil systems. Therefore, nitrogen management in early-stage invasions may hold the key to mitigate plant invasion.