Invasive Plant Impact in Grassland Ecosystem: A meta-analysis and its implications for the food-water-energy security

Abstract

Invasive plant species can exert systemic pressures that weaken the resilience of grassland ecosystems. However, their impact on the food-energy-water security has yet to be assessed quantitatively and comprehensively. This study synthesizes 146 studies from various global grasslands to evaluate the ecological consequences of plant invasions on food, water, and energy security. The meta-analysis revealed 31-113% increase in biomass, as well as 16% and 13% increases in soil organic carbon and soil nitrogen, respectively. However, this increase is accompanied by a 32% decline in native species diversity, which reduces the long-term stability of food systems. Hydrological processes also changed, with increases in ammonium (5,5%) and nitrate (9,4%), indicating a decline in water quality. While changes in soil moisture were insignificant, shifts in microbial dynamics and soil structure were functionally important for water regulation. The most significant findings relate to energy-carbon dynamics. Though the number of studies measuring greenhouse gases remains limited, the substantial increase in soil respiration, CO₂, N₂O, and CH₄ emissions signals substantial potential climate risk. Overall, plant invasions result in significant trade-offs in the food-energy-water security. These findings underscore the importance of controlling invasive species to ensure food-energy-water security in grassland ecosystems.