Plant genus is a better predictor of plant effects on soil biotic and abiotic properties than plant invasive status

Abstract

Abstract Increasing evidence suggests that plant invasions are promoted by altered plant-soil interactions. However, we still lack studies exploring differences in the effects of invasive and native species on soil properties, and particularly studies that would control for species phylogeny and abundance. Here, we grew seven congeneric pairs of invasive and native species with comparable cover in the studied region in a 12-weeks garden experiment. We analysed the amount of nutrients, pH and composition and amount of soil biota in soils cultivated by each species and in uncultivated soil. Then we used ratios of the soil characteristics in cultivated and uncultivated soil to express species effects on the soil. Invasive species used more phosphorus from the soil and supported mycorrhizal communities with higher potential to colonize plant roots than native species, but did not differ in any other soil properties. In contrast, we found strong differences among plant genera and genera from the same families tended to cluster together in their effects on the soil. We also found many interactions of genera and invasion status. Effects of plants on the soil were also largely determined by plant biomass production independent of species identity. The results suggest that invasive and native species differ only in a few general effects on the soil and that the differences among native and invasive species are largely genus specific. They also indicated that species phylogenetic identity and individual plant biomass should be considered in future studies of the effect of plants on the soil.