Substrate availability regulates the suppressive effects of Canada goldenrod invasion on soil respiration

Abstract

Aims Invasive alien plants cannot only decrease riparian vegetation diversity but also alter wetland ecosystem carbon processes, especially when they displace the original vegetation. Invasive Canada goldenrod (Solidago canadensis) has colonized large areas of disturbed and undisturbed land in southeastern China, yet little is known regarding how it affects soil carbon cycling. To explore the response patterns of soil respiration following S. canadensis invasion and their driving mechanisms, an observational field study and a greenhouse experiment simulating invasion were performed. Methods In the field study, soil respiration was measured weekly from 21 th of July to 15 th of December 2018. In the greenhouse experiment, soil respiration, autotrophic and heterotrophic respiration was measured every 1 st and 15 th of the month 15 th of July to 15 th of December 2019. Soil, autotrophic and heterotrophic respiration were measured using a closed-chamber system with the deep gauze collar root exclusion method. Important Findings Solidago canadensis invasion appeared to decrease the total soil CO2 emissions in both the field study and the greenhouse experiment. The suppressive effects on soil respiration may be attributed to S. canadensis invasion-induced alterations in the quality and quantity of available soil substrate, suggesting that S. canadensis invasion may impact soil carbon cycling via plant-released substrates and by competing for the soil available substrate with native plant and/or soil microbes. These results have substantial implications for estimations of the effects of invasive plants on belowground carbon dynamics and their contribution to the warming world.

Canada Goldenrod Invasion Regulates the Effects of Soil Moisture on Soil Respiration

“…In detail, S. canadensis can affect soil total respiration by affecting the root system of the invaded vegetation community and the composition and structure of the microbial community through changing the availability of soil substrates. S. canadensis invasion alters autotrophic respiration by interfering with root nutrient absorption and utilization and limiting root physiological activities [ 34 ]. Moreover, S. canadensis alters heterotrophic respiration by affecting the microbial decomposition of soil organic matter and litter through changing the composition, structure, and metabolic activity of the soil microbial community [ 33 , 50 ].…”

“…The root exclusion method, based on inserting deep gauze collars (diameter: 5.0 cm and height: 30 cm) at the same place of pots, was drawn upon to distinguish soil total respiration into heterotrophic and autotrophic respiration. Soil total, heterotrophic, and autotrophic respiration were calculated following the equations described in the previous study [ 34 , 37 , 38 ].…”

“…The impact of S. canadensis on soil respiration have rarely been examined [ 32 ]. Previous studies have found that the invasion of the riparian wetlands by S. canadensis affected soil respiration and the carbon cycle in the invasion area, and with the intensification of the invasion, soil respiration showed a decreasing trend [ 33 , 34 ]. This inhibition of soil respiration might be caused by the changes in the underground soil microenvironment and aboveground vegetation community structure under S. canadensis invasion.…”

Nitrogen Deposition Enhanced the Effect of Solidago Canadensis Invasion on Soil Microbial Metabolic Limitation and Carbon Use Efficiency

“…This competitive dynamic may further modify the physiology and behaviour of individual microbes, alter the structure and function of microbial communities, and ultimately affect the carbon use efficiency of microbes [38]. Furthermore, increased moisture promotes the growth of Solidago canadensis, which favours moist environments [39]. Thus, to counterbalance microbial carbon limitation and mitigate the detrimental effects of changes in water and nutrients prompted by Solidago canadensis invasion, microbes make trade-offs.…”

Effect of litter decomposition on mowing and plant composition change during Solidago stand restoration

“…The two invasive species of North American provenance that are found in Central Europe most frequently are Solidago gigantea Aiton (Giant goldenrod) and Solidago canadensis L. (Canadian goldenrod) (Tokarska-Guzik et al, 2014;Lukash et al, 2021;Meyer 2022;Popay & Parker, 2022). S. canadensis may decrease soil respiration, which affects soil carbon cycling through substrates emitted by plants, as well as by competing with native plants and soil microorganisms for the available substrate (Hu et al, 2022b;Xu et al, 2022). S. canadensis invasion has been shown to reduce soil organic carbon, total nitrogen, and cation exchange capacity (Xie et al, 2022).…”