Differential influence of four invasive plant species on soil physicochemical properties in a pot experiment.

Purpose: This study compared the effects of four invasive plants, namely <italic>Impatiens glandulifera</italic>, <italic>Reynoutria japonica</italic>, <italic>Rudbeckia laciniata</italic>, and <italic>Solidago gigantea</italic>, as well as two native species—<italic>Artemisia vulgaris</italic>, <italic>Phalaris arundinacea</italic>, and their mixture on soil physicochemical properties in a pot experiment.Materials and methods: Plants were planted in pots in two loamy sand soils. The soils were collected from fallows located outside (fallow soil) and within river valley (valley soil) under native plant communities. Aboveground plant biomass, cover, and soil physicochemical properties such as nutrient concentrations, pH, and water holding capacity (WHC) were measured after two growing seasons. Discriminant analysis (DA) was used to identify soil variables responsible for the discrimination between plant treatments. Identified variables were further compared between treatments using one-way ANOVA followed by Tukey’s HSD test.Results and discussion: Plant biomass, cover, and soil parameters depended on species and soil type. DA effectively separated soils under different plant species. DA on fallow soil data separated <italic>R. laciniata</italic> from all other treatments, especially <italic>I. glandulifera</italic>, native species and bare soil, along axis 1 (related mainly to exchangeable K, N-NH₄, total P, N-NO_3, and WHC). Large differences were found between <italic>R. laciniata</italic> and <italic>S. gigantea</italic> as indicated by axis 2 (S-SO₄, exchangeable Mg, total P, exchangeable Ca, and total Mg). DA on valley soil data separated <italic>R. japonica</italic> from all other treatments, particularly <italic>S. gigantea</italic>, <italic>R. laciniata</italic>, and native mixture, along axis 1 (N-NO₃, total N, S-SO₄, total P, pH). Along axis 2 (N-NO₃, N-NH₄, Olsen P, exchangeable K, WHC), large differences were observed between <italic>I. glandulifera</italic> and all other invaders.Conclusions: Plant influence on soil differed both among invasive species and between invasive and native species. <italic>Impatiens glandulifera</italic> had a relatively weak effect and its soil was similar to both native and bare soils. Multidirectional effects of different invaders resulted in a considerable divergence in soil characteristics. Invasion-driven changes in the soil environment may trigger feedbacks that stabilize or accelerate invasion and hinder re-colonization by native vegetation, which has implications for the restoration of invaded habitats. [ABSTRACT FROM AUTHOR]