Root system asymmetry of Mediterranean pines

• Published in: Plant and soil 2005-12, Vol.278 (1-2), p.75-83
• Main Authors: Ganatsas, P, Spanos, I
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Artificial regeneration. Forest nurseries. Planting; Asymmetry; Biological and medical sciences; Contour lines; Economic plant physiology; Forest management. Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Forest soils; Forestry; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Morphology. Anatomy. Histology. Cytology; Pine trees; Pinus brutia; Pinus halepensis; Plant growth; Plant roots; Plants; Root systems; Roots; Saplings; Section II: Root system morphology and anchorage; Seedlings; Slope stability; Soil depth; soil physical properties; Soil surfaces; Soil water; soil water content; soil-plant interactions; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments; Sowing and planting; Stand types and stand dynamics. Silvicultural treatments. Tending of stands. Natural regeneration; Symmetry; Trees; Water availability
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-005-1092-3

Three groups of Mediterranean pines were examined to describe the development of root symmetry on sites characterized by shallow soils and low water availability. Sampling included: (1) 3-year-old planted seedlings of Pinus halepensis Mill, taken from Sithonia Halkidiki, northern Greece, (2) 5-year-old natural regenerated seedlings of Pinus brutia Ten. taken from Kedrinos Lofos, Thessaloniki and (3) 65-year-old trees of Pinus brutia taken from Kedrinos Lofos, Thessaloniki. Root system symmetry was examined by measuring the number, the diameter, the cross-sectional area (CSA), the root area index (RAI) and the length of the lateral roots of each root system, and by analyzing their distribution around the stem. Above-ground plant symmetry was also estimated. The findings of the study indicated that there was an asymmetric root system in all three groups that is characterized by the concentration of the main laterals along the contour lines instead of uphill or downhill; however, the asymmetry was much higher in the young plants. This asymmetry was not correlated with the above-ground plant growth form, which was found to be symmetric. The asymmetric development of root can be attributed to the shallow soil and the high mechanical resistance of the underground bedrock that stopped the taproot growth, restricted the root penetration in the deeper layers and obliged the roots to elongate towards the surface soil layers, where there is more available water.