Nutrient acquisition and soil nutrient mineralization by exotic range-expanding and related native plants

Background/Question/Methods Due to climate warming, plants can expand their range to higher latitudes. Some of these exotic range-expanding plants may become invasive in the new range. When exotic range-expanding plants establish in the new range, new interactions between soil microbes and plants can alter rhizosphere-driven nutrient mineralization and litter decomposition. To study these interactions, two experiments were performed: one in a greenhouse and one in a climate chamber. In the greenhouse, we studied if exotic range-expanding plants might alter rhizosphere nutrient mineralization and plant nutrient acquisition compared with congeneric natives. In the climate chamber, we studied if litter of range-expanding plants might alter soil nutrient availability and litter feedback to plant biomass production. We compared exotic and related native plants.

Results/Conclusions We observed species-specific differences in rhizosphere nutrient mineralization and plant nutrient acquisition, but no consistent differences between exotic range-expanding plants and congeneric natives. We also found species-specific differences in soil nutrient availability and litter feedback to plant biomass production, but soil N availability was increased more often by litter of exotic range-expanding plants than of related native plants. This increase in soil N availability resulted in increased biomass production for both exotic range-expanding and related native plants. Our results suggest that exotic range-expanding plants may alter N cycling, but that these effects are species-specific and not consistently different between plant origins. If litter of exotic range-expanders increases N cycling, this can create a positive feedback to plant biomass production for both exotic range-expanding and native plants.