Habitat‐specific responses of soil organic matter decomposition to Spartina alterniflora invasion along China's coast

Abstract

Plant invasions cause a fundamental change in soil organic matter (SOM) turnover. Disentangling the biogeographic patterns and key drivers of SOM decomposition and its temperature sensitivity (Q10) under plant invasion is a prerequisite for making projections of global carbon feedback. We collected soil samples along China's coast across saltmarshes to mangrove ecosystems invaded by the smooth cordgrass (Spartina alterniflora Loisel.). Microcosm experiments were carried out to determine the patterns of SOM decomposition and its thermal response. Soil microbial biomass and communities were also characterized accordingly. SOM decomposition constant dramatically decreased along the mean annual temperature gradient, whereas the cordgrass invasion retarded this change (significantly reduced slope, p < 0.05). The response of Q10 to invasion and the soil microbial quotient peaked at midlatitude saltmarshes, which can be explained by microbial metabolism strategies. Climatic variables showed strong negative controls on the Q10, whereas dissolved carbon fraction exerted a positive influence on its spatial variance. Higher microbial diversity appeared to weaken the temperature‐related response of SOM decomposition, with apparent benefits for carbon sequestration. Inconsistent responses to invasion were exhibited among habitat types, with SOM accumulation in saltmarshes but carbon loss in mangroves, which were explained, at least in part, by the SOM decomposition patterns under invasion. This study elucidates the geographic pattern of SOM decomposition and its temperature sensitivity in coastal ecosystems and underlines the importance of interactions between climate, soil, and microbiota for stabilizing SOM under plant invasion.

Biochemical characterization and mycorrhizal fungal community of plant species in the Brazilian seasonal dry forest

“…Other works have corroborated our results about high values for total glomalin, exchangeable Na and Ca, and soil organic carbon at invaded habitats [36]. Our results highlight the ability of IAPS to change the soil biochemical properties in their rhizosphere [37, 38].…”

Perspectives of invasive alien species management in China

“…Disentangling these biogeographic patterns and key drivers of soil organic matter (SOM) decomposition and its temperature sensitivity under plant invasion is crucial for projecting global carbon feedback. Zhang et al (2023) found inconsistent responses to invasion among habitat types, with SOM accumulation in salt marshes but carbon loss in mangroves. These variations were at least partially explained by the patterns of SOM decomposition under invasions.…”