Effects of climate and soil properties on growth of Pinus pinea young plantations

Growth of Pinus pinea forests and plantations in native countries is known to be affected by soil and climate characteristics. However, edaphoclimatic drivers of growth and fruiting have been scarcely studied outside the species’ native range; in addition, the role of soil nutrients, particularly in juvenile trees’ development, has been poorly explored.

Relationships between edaphoclimatic variables and the performance of 54 young plantations were studied in Chile. Vegetative growth and fruiting were measured in 100 randomly selected trees per plantation. Composite soil samples were taken from each site to analyze soil chemical characteristics and texture. A principal component analysis was performed including climatic, soil data, and growth and fruiting variables.

Annual growth was 1.3 cm year⁻¹ for stem diameter, 28.3 cm year⁻¹ for crown diameter, and 38.9 cm year⁻¹ for height; cone production per crown area was 0.07 cones m⁻². Negative correlation of height growth, crown growth and cone production with EC, Na, and pH were found, along with positive correlations with OM, PP and the index PP × AT. Stem diameter growth was favored by less acidic soils with high sand content, and showed no correlation with cone production. Furthermore, vegetative growth was positively correlated with N, P, Mg and clay content. In young plantations, vegetative growth was higher than in the species’ native habitat.

Soil properties, in particular low EC and Na were identified as favorable for growth of young stone pine trees, along with high content of soil N, P and Mg, and PP.