Rising CO2 and ecosystem sustainability: The role of carbon fertilisation

Globally, plant functioning and ecosystem processes are changing due to rising atmospheric CO₂ concentrations. The carbon fertilization effect is the term used to describe how elevated CO₂ usually improves photosynthesis, increases water-use efficiency, and stimulates biomass accumulation. However, there are significant differences between species and ecosystems in the intensity, duration, and ecologica significance of this response. While changes in soil microbial activity can affect nutrient cycling, decomposition, and organic matter stability, nutrient limitations, especially those related to nitrogen and phosphorus, frequently limit plants' ability to convert surplus carbon into long-term growth. Forests, grasslands, croplands, wetland systems, and arid landscapes each display distinct sensitivities to elevated CO₂ depending on hydrology, soil fertility, dominant vegetation types, and disturbance regimes. Although enhanced CO₂ can support higher productivity, greater vegetative cover, and improved drought tolerance in some systems, it may also reduce plant nutrient concentrations, alter competitive dynamics, and weaken ecosystem stability. In agricultural systems, increased carbohydrate accumulation under elevated CO₂ frequently results in nutrient dilution, posing risks to food quality and human nutrition. At the same time, potential gains in carbon sequestration depend on long-term storage in wood, roots, and soil organic matter, which remain uncertain under variable climate and nutrient conditions. Reliable management strategies such as improved nutrient stewardship, soil carbon-building practices, and development of CO2-responsive cultivars are essential to harness benefits while minimizing ecological trade-offs. A deeper integration of experimental findings, long-term monitoring, and ecosystem modelling is needed to better predict how rising CO₂ will shape sustainable terrestrial systems in the future.