Effects of Trifolium repens invasion on functional traits and turf quality of Poa pratensis

Abstract

Abstract [Objective] Invasion of Trifolium repens occupies the living space of turfgrasses and has been seriously threatening the quality and function of turfs. Examining the impact of T . repens invasion on the functional traits of Poa pratensis and turf quality is helpful for understanding the invasion mechanism of T . repens and for establishing and maintaining gramineous turfgrass. [Methods] Taking the T . repens-invaded P . pratensis turf as object, the sample survey method was employed to investigate the differences in the functional traits and turf quality of P . pratensis under different degrees of T . repens invasion (control, low invasion, moderate invasion, and heavy invasion), and to evaluate turf quality by the membership function method. [Results] (1) With increase in degree of T . repens invasion, the carbon content of P . pratensis organs and the cost of leaf construction, as well as the ratio of carbon to nitrogen, carbon to phosphorus, and nitrogen to phosphorus were gradually decreased, while the specific leaf area and nitrogen and phosphorus content in the organs were increased. (2) At the same invasion level, the carbon, nitrogen, and phosphorus contents in the organs of P . pratensis were higher in leaves than in roots and stems, and the carbon to nitrogen ratio and carbon to phosphorus ratio were higher in roots and stems than in leaves, while the nitrogen to phosphorus ratio was higher in stems and leaves than in roots. (3) The density, texture, greenness index, and uniformity of P . pratensis turf were decreased with increase in T . repens invasion, while the aboveground biomass and belowground biomass were increased. (4) The comprehensive evaluation by the membership function method showed that turf quality was the best without T . repens invasion but the worst under heavy T . repens invasion. Leaf carbon content had the greatest influence on turf quality. [Conclusion] T . repens invasion alters P . pratensis functional traits as well as affects turf quality, landscape, and function.

Keywords

• plant invasion
• trifolium repens
• poa pratensis
• plant functional traits
• turf quality