Abstract
The present study utilized the Cooperative Program on Pine Research in Brazil (PPPIB) experiment to investigate the development of Pinus caribaea var. hondurensis and Pinus taeda grown under two fertilization regimes (fertilized and control treatments). Fertilized plots received fertilization at two stages: in the first year of tree growth with a mix of N, P, K, Ca, Mg, S, and micronutrients, and a mid-rotation application (7 years later) of NPK fertilizer. Forty-eight trees, aged 11 years, were selected (12 per treatment, with three replicates per plot), and wood cores (four samples per tree) were collected using a Pressler increment borer. The growth, climate-growth relation, and intrinsic water use efficiency (WUEi) of the trees were assessed by a combined analysis of cross-sectional area (CSA) increment, water balance and carbon isotope discrimination (Δ13C ‰). The effect of fertilization on tree growth regime was assessed using inventory data collected yearly over 8 years. Additionally, monthly data of wood increments, monitored in non-fertilized stands over a period of 6 years, were utilized for correlations with meteorological variables (air temperature, rainfall, vapor pressure deficit, solar radiation and potential and actual evapotranspiration). The growth of P. caribaea and P. taeda was strongly influenced by multiple meteorological variables related to water availability and evapotranspiration. Carbon isotope analysis revealed that fertilized trees exhibited higher Δ13C values in some years, indicating improved water uptake efficiency due to increased nutrient availability, which enhanced photosynthetic performance. Pinus caribaea outperformed P. taeda in wood productivity and exhibited a heightened responsiveness to fertilization. In general, P. caribaea was shown to be more water-use efficient than P. taeda, as it is able to use smaller amounts of water for greater wood production. The study’s outcomes provide valuable guidance for managing tree plantations and adopting sustainable practices, particularly as climate change and increasing droughts demand greater resilience in wood production.
Biography
Dr. Deborah Santos is a Forest Engineering graduate from the Federal University of Goiás (UFG), with a Master’s and PhD in Forest Resources from the University of São Paulo (USP). Her career focuses on the complex interplay between climate change and forestry. Her specialize in Silviculture and Forest Management, with expertise in tree growth, productivity, and ecophysiology. She use isotope techniques, including δ15N and δ13C, to assess plant nutrition and enhance water and nutrient use efficiency. Her work also encompasses studies on wood quality, bioenergy, cellulose pulp, and dendrochronology. Additionally, She involved in carbon market initiatives and sustainability solutions, focusing on Forest Restoration, Reducing Emissions from Deforestation and Forest Degradation (REDD), the Climate, Community and Biodiversity Alliance (CCBA), and solid waste management with an emphasis on bioenergy.