DOI: 10.5061/dryad.zgmsbccff
title: Data for: Responses of soil phosphorus cycling and bioavailability to plant invasion in river-lake ecotones

description: The invasion of exotic plants in the river-lake ecotone has seriously
 affected the nutrient cycling processes in wetland soil. The South
 American species Alternanthera philoxeroides (Mart.) Griseb. is rapidly
 invading the river-lake ecotone in subtropical China, and has become the
 dominant species in the river-lake ecotone. However, there have been few
 studies on the effects of A. philoxeroides invasion on soil phosphorus (P)
 cycling and bioavailability in this ecotone. Herein, we measured the
 bioavailable P fractions, physicochemical properties and nutrient content
 in the surface soils of the native plant (Zizania latifolia (Griseb.)
 Turcz and Nelumbo nucifera Gaertn.) communities and the adjacent invasive
 A. philoxeroides communities in three river-lake ecotones with different
 nutrient substrates in the subtropical Dongting Lake basin over a
 three-year period to reveal the effects of A. philoxeroides invasion on
 the morphology and concentrations of soil bioavailable P. The principal
 coordinate analysis results showed that A. philoxeroides invasion
 significantly altered the bioavailable P concentrations in the soil of
 native plant communities in the different river-lake ecotones, and this
 effect was not disturbed by the heterogeneity of the soil matrix. However,
 the effects of invasion into different native plant communities on the
 fractions of soil bioavailable P were different. Compared with native Z.
 latifolia and N. nucifera communities, A. philoxeroides invasion increased
 the concentration of inorganic P by 39.5% and 3.7%, respectively, and the
 concentration of organic P decreased by 32.7% and 31.9%, respectively.
 Meanwhile, the invasion promoted P cycling and accumulation in the
 river-lake ecotone, which resulted in average decreases in the soil N:P
 and C:P ratios of 7.9% and 12.5%, respectively. These results highlight
 the impact of exotic plant invasions on nutrient cycling in wetland
 ecosystems in the river-lake ecotone, and this process may be detrimental
 to the late recovery of native plants.
description: Prior to data analysis, log10
 and square root arcsine transformations were conducted to ensure normality
 and homogeneity of variance. One-way ANOVA was used to test the effect of
 site or plant type on the soil bioavailable P fraction, and Tukey’s test
 was used to compare the differences in bioavailable P contents among sites
 or plant communities. Two-way repeated-measures ANOVA was used to analyze
 the effects of the site and invasion time and their interaction on soil
 bioavailable P fractions. A linear mixed model (LMM) was used to analyze
 the effect of plant invasion on the native community, in which plant
 invasion was set as a fixed variable, sites and invasion time were set as
 random variables, and soil physicochemical properties, nutrient contents
 and stoichiometric ratios were set as continuous dependent variables. The
 analysis was performed using the "lme4" package in R, and the
 "glmm.hp" package was used to calculate
 <em>R</em><sup>2</sup> values for fixed and random
 effects (Nakagawa & Schielzeth, 2013). The standardized major axis
 (SMA) was used to analyze the scaling relationships of the P content and
 N:P and C:P ratios in aboveground and belowground plant organs. The
 "SMATR" package in R was used for the scaling relationship
 analysis, and a likelihood ratio test was performed to compare
 differences in the allometric index between different native plants and
 their adjacent invasive plant species (Hu et al., 2021; Warton et al.,
 2012). Principal coordinate analysis (PCoA) was used to test the
 differences in soil bioavailable P fractions among different
 plant communities, and the method was multivariate analysis of variance
 (Adonis test) based on the Bray‒Curtis distance. Linear regression models
 were constructed to analyze the relationships between soil bioavailable P
 fractions and soil physicochemical properties in different plant
 communities. The differences between the slopes of linear regression
 models were compared using the "diffslope" function in R (Nekola
 & White, 1999). The "vegan" package was also used for
 the redundancy analysis of the effect of soil physicochemical properties
 on soil bioavailable P fractions, and "rdacca.hp" was used to
 perform a hierarchical analysis to determine the contribution of a single
 physicochemical factor to the bioavailable P fractions (Lai et al., 2022).
 Pearson’s correlation analysis was conducted to study the relationship
 between soil bioavailable P contents and soil physicochemical properties
 in plant communities. The analyses described above were performed using
 SPSS 23.0 (SPSS, Chicago, Illinois, USA) and R Version 4.1.1 (R
 Development Core Team, 2020).
description: Output units are described in the ReadMe_file.rtf file.