Plant water relations and edaphoclimatic conditions affecting acorn production in a holm oak (Quercus ilex L. ssp. ballota) open woodland

• Published in: Agroforestry systems 2010-03, Vol.78 (3), p.299-308
• Main Authors: Carevic, F. S, Fernández, M, Alejano, R, Vázquez-Piqué, J, Tapias, R, Corral, E, Domingo, J
• Format: Article
• Language: English
• Subjects: acorns; Agriculture; Agronomy. Soil science and plant productions; Biological and medical sciences; Biomedical and Life Sciences; Climate; Climatic conditions; climatic factors; Cuticular transpiration; edaphic factors; forest trees; Forestry; Fundamental and applied biological sciences. Psychology; Land use; Life Sciences; Mediterranean climate; Moisture content; plant adaptation; plant cuticle; plant-water relations; plowing; Quercus ilex; seasonal variation; seed set; seeds; Soil depth; Soil treatment; Soil water; soil water retention; Soils; sowing; stomatal movement; temporal variation; Transpiration; Water availability; Water content; Water depth; water holding capacity; Water potential; Water relations; Woodlands
• ISSN: 0167-4366; 1572-9680
• DOI: 10.1007/s10457-009-9245-7

Acorn production patterns and the annual evolution of water relations parameters of Quercus ilex ssp. ballota (Desf.) Samp. in a dehesa (an open woodland forest) subject to various soil treatments (ploughing, ploughing + sowing, control) were studied in southwest Spain from June 2006 to December 2008. The effects of soil water holding capacity and effective soil depth on soil and plant water status and acorn production were also investigated. Water parameters showed significant differences between the ploughing treatment and the control, and there were also significant temporal differences. Xylem water potential ranged from −3.4 ± 0.1 to −0.7 ± 0.2 MPa, and cuticular transpiration was 62.4-192.9 mmol H₂O kg⁻¹ s⁻¹. Acorn production did not differ significantly according to soil treatment, and showed large intra-specific variability. Individual values ranged from 0 to 1,220 g m⁻² (fresh weight). Positive relationships were found between xylem water potential, cuticular transpiration and relative water content measured at midsummer, and acorn production during the three studied years. These results suggest that climatic conditions and soil water availability have a strong influence on plant water status, and therefore on acorn development during summer. The results also reflect the ability of this species to adapt to the Mediterranean climate by preserving water during dry periods, which to a large extent can be attributed to stomatal closure at high relative water content levels, and low cuticular transpiration during these periods.