Enhancing climate-smart forestry with fertilization

Can fertilizing forests help fight climate change? What role could fertilization play in multi-objective forestry, where wood production, carbon sequestration, and environmental sustainability must be balanced?

In my PhD research, I explore how forest fertilization influences tree physiology, growth, and carbon dynamics. Together with the research team, we use tree core samples to reconstruct trees’ life histories across their entire lifespan. Annual growth rings reveal how trees responded to fertilization over time, while stable carbon isotope analyses provide insight into changes in photosynthetic performance. In addition, needle analyses are central to understanding how nutrient availability translates into physiological change.

Fertilization affects trees first and foremost through their foliage. Improved nutrient availability enhances needle mass and chlorophyll concentrations, which increases photosynthetic capacity and leads to greater carbon assimilation and increased tree growth. Increased needle production also results in greater litterfall. As needles senesce and fall to the forest floor, they contribute organic matter to the soil, increasing carbon inputs and potentially strengthening soil carbon stocks. Through these interconnected processes—improved nutrient status, enhanced photosynthesis, greater biomass production, and increased litter input—fertilization may amplify both aboveground and belowground carbon sequestration.

This research aims to clarify under which conditions fertilization can serve as a climate-smart forestry tool, contributing simultaneously to sustainable wood production, stronger carbon sinks, and a resilient bioeconomy.