Increased and fluctuating phosphorus nutrient availability positively affects the growth of the invasive plant Solidago canadensis

Abstract

Phosphorus and biological invasions are rapidly altering global ecosystems at an unprecedented rate. The natural deposition rate of phosphorus is fluctuates, and the accumulation and release of resources over time often result in resource pulses. This study aimed to investigate the effects of phosphorus fluctuations on Solidago canadensis. We selected S. canadensis as the target species and implemented two planting methods, namely non-competition and intraspecific-competition. Both were subjected to seven treatments with varying concentrations and timing of nutrient supply (control, constant low, constant high, gradual decrease, gradual increase, single pulse, and multiple pulses). After ten weeks, we measured the growth, physiological, and chemical characteristics of S. canadensis. We found that (1) Phosphorus supplementation (low versus high) both promoted the growth of S. canadensis planted with one seedling per pot, and phosphorus nutrient of gradual decrease resulted in S. canadensis having higher total biomass. (2) For S. canadensis with intraspecific-competition, a high phosphorus nutrient supply can promote growth. Compared with the method of constant high, the single-pulse phosphorus nutrient method had a more obvious promotion effect on the total biomass. Our results indicated that changes in phosphorus nutrient supply concentration and time did not significantly affect the physiological and biochemical indicators of S. canadensis. However, high phosphorus nutrients and fluctuations positively impacted the growth of S. canadensis, especially in the context of non-competition and intraspecific-competition. Consequently, mitigating phosphorus nutrient availability and fluctuations emerges as a potential strategy to decelerate the growth of the invasive plant S. canadensis.