Invasive C4 plants cause greater soil greenhouse gas emissions than C3 plants

Understanding the impact of invasive plants on the emissions of soil greenhouse gases (GHGs) is essential for developing effective strategies to mitigate invasion-induced ecosystem disruption and climate warming. Here we present a global meta-analysis of 104 studies to assess the effects of plant invasion on soil carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions. Our results showed that plant invasion significantly increased all three GHG emissions from soils. Model selection analysis indicated that the photosynthetic pathway of invasive plants (C3 or C4) and soil organic carbon (SOC) were the primary factors governing the variation in GHGs emissions. Specifically, invasion by C4 plants increased all three GHG emissions from soils more than C3 plants, whereas SOC mainly influenced the invasion-induced emissions of soil CO2 and CH4. These findings provide mechanistic insights into how invasive plants alter soil GHG fluxes and cause the associated impacts on biogeochemical cycles.