Growth and competitive interaction between seedlings of an invasive Rumex confertus and of co-occurring two native Rumex species in relation to nutrient availability

Jeremi Kołodziejek

doi:10.1038/s41598-019-39947-z

Abstract

Rumex confertus is an alien invasive perennial plant that has increased its range rapidly within central Europe in the last 100 years. This study examined the effects of a commercial fertilizer on the competition between the invasive Rumex confertus and two non-invasive native species R. acetosa or R. conglomeratus in terms of morphological and physiological traits and relative yield. All three Rumex species were grown in the open field with two levels of nutrient availability in field plots. Competition and fertilizer had significant effects on height, relative growth rate (RGR), specific leaf area (SLA) as well as shoot and root biomass of all three species. The fertilized plants had high macronutrient and nitrate contents in leaf tissue. Relative yield of R. confertus was <1, indicating that for this species the effects of interspecific competition were greater than those of intraspecific competition. The results of this experiment indicate that there is interaction between the nutrient status of the soil and the competition between species. Competitive superiority of R. confertus could explain its dominance in grasslands and in disturbed areas, and might explain its great influence on the occurrence of native species because competition intensity was high in fertilized plots.

Highlights

Competition is likely to be an important determinant of plant community structure and is considered one of the most important factors promoting successful invasive potential[1,2]
In unfertilized and fertilized plots, the height of both native species was significantly decreased by the invasive species
Analysis of variance showed that the seedling heights of R. confertus, R. conglomeratus and R. acetosa were influenced by competition

Summary

Introduction

Competition is likely to be an important determinant of plant community structure and is considered one of the most important factors promoting successful invasive potential[1,2]. Other studies have showed that hydrological disturbance affected nutrient availability because nitrates were readily leached from oxidized soil during drainage[14]. Experimental studies showed greater relative performance of invasive species than of native ones in N-enriched treatments, implying reduced success of invasives relative to natives in N-poor sites[18,19,20]. Www.nature.com/scientificreports to of agricultural activities or roadside pollutants was shown to increase the number of N-loving invasive species in relation to native ones in N-poor environments, such as coastal, calcareous and sandy grasslands[21]. Numerous studies on competition demonstrated that excess fertilization and manure production on agricultural lands created surplus N, which was mobile in many soils and often leached to downstream aquatic ecosystems, or volatilized to the atmosphere, could be redeposited elsewhere eventually reaching aquatic ecosystems[11]. Because phosphorus availability (primarily as orthophosphate) is the limiting element for freshwater macrophytes[25], reducing phosphorus levels might help in controlling competitiveness of invasive macrophytes[24]

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Discussion

Conclusion