Effect of stand density and pruning on growth of ponderosa pines in NW Patagonia, Argentina

• Published in: Agroforestry systems Vol. 78; no. 3; pp. 233 - 241
• Main Authors: Gyenge, J. E, Fernández, M. E, Schlichter, T. M
• Format: Journal Article
• Language: English
• Published: Dordrecht Dordrecht : Springer Netherlands 01.03.2010; Springer Netherlands; Springer; Springer Nature B.V
• Subjects: Agricultural production; Agriculture; Agronomy. Soil science and plant productions; Biological and medical sciences; Biomedical and Life Sciences; Carbon fixation; Cropping systems. Cultivation. Soil tillage; diameter; Drought resistance; drought tolerance; dry matter partitioning; Environmental impact; Foliage; forest plantations; forest trees; Forestry; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Growth rate; leaves; Life Sciences; overstory; photosynthesis; Pine trees; Pinus ponderosa; plant available water; Plant growth; Plantations; Planting density; pruning; rotation duration; silvicultural practices; silvopastoral systems; stand density; Tending. Growth control; Tillage. Tending. Growth control; timber production; tree growth; Trees; Water availability; Argentina; South America; America; Patagonia; Argentina, Patagonia; Pruning; Thinning; Forest productivity; Silvicultural treatments; Silvopastoral systems; Forests; Primary productivity; Silvopastoral system; Stand density; Silviculture; Patagonia; Pinus ponderosa; Softwood forest tree; Gymnospermae; Coniferales; Spermatophyta; Agroforestry
• ISSN: 0167-4366; 1572-9680
• DOI: 10.1007/s10457-009-9240-z

Due to the lack of knowledge about ponderosa pine performance under silvopastoral systems (SPS) conditions, the objective of this study was to determine the effect of stand density and pruning on the growth magnitude of ponderosa pines growing in NW Patagonia (SPS with 350 and 500 pines ha⁻¹ vs. commercial densities of 1,300 trees ha⁻¹, HPP). Individual growth rate was higher in SPS 350 trees than in SPS 500 trees, being both higher than in HPP plots, indicating a higher sensitivity of this drought resistance species to relative water availability. The higher individual growth compensated the lower amount of trees per land unit, being the whole stand growth similar or even higher in both SPS treatments than in the HPP stand. Pruning reduced diameter growth in both SPS treatments, at least until 2 years after pruning, with a more marked effect in the pruning treatment with the higher amount of extracted foliage. Carbon fixation reduction in addition to changes in carbon allocation within different plant parts after pruning could be the responsible of observed stem growth reductions. We suggest that higher growth rates in combination with frequent pruning in low density plantations can be applied to shorten the rotation period producing high quality timber in comparison with plantations managed under conventional conditions in Patagonia. Additional advantages could be associated to the lower environmental impact of low canopy cover plantations compared to high density stands.