Drivers of carbon accumulation in eucalypt plantations: a multivariate analysis and prediction models for Australian and Brazilian experiments

Abstract

To understand the drivers of carbon uptake in eucalypt plantations in Australia and Brazil, we conducted an exploratory analysis using data from 448 experiments, considering factors such as longitude, latitude, elevation, age, rainfall, temperature, and carbon accumulation. Principal component analysis was used to identify the most influential variables affecting carbon accumulation, while generalized additive models were applied to develop predictive models based on the best variable combinations. Our findings revealed that Brazilian eucalypts plantations exhibited a higher average carbon accumulation than Australian ones, with values of 9.89 MgC ha⁻¹yr⁻¹ and 5.91 MgC ha⁻¹yr⁻¹, respectively. Rainfall, mean annual temperature and elevation were strongly correlated with carbon accumulation in the multivariate analysis for both countries. Additionally, for every 100 mm yr⁻¹ increase in rainfall, the average carbon sequestration rate increased by 0.744 MgC ha⁻¹yr⁻¹ in Brazil and 0.356 MgC ha⁻¹yr⁻¹ in Australia. The observed variation in species composition across the dataset highlights the importance of implementing tailored management strategies to optimize carbon uptake in eucalypts plantations. These findings provide valuable insights for enhancing the climate change mitigation potential of eucalypt forestry through regionally adapted management practices.