Radial variation of vessel size and distribution in cork oak wood (Quercus suber L.)

2006 ◽  
Vol 41 (4) ◽  
pp. 339-350 ◽  
Author(s):  
Sofia Leal ◽  
Vicelina B. Sousa ◽  
Helena Pereira
Keyword(s):  
Quercus Suber ◽  
Cork Oak ◽  
Radial Variation ◽  
Vessel Size ◽  
Oak Wood

Azimuthal variations in xylem structure and water relations in cork oak (Quercus suber)

IAWA Journal ◽  
2011 ◽  
Vol 32 (1) ◽  
pp. 25-40 ◽  
Author(s):  
Nadia Barij ◽  
Jan Čermák ◽  
Alexia Stokes
Keyword(s):  
Moisture Content ◽  
Water Relations ◽  
Sap Flow ◽  
Quercus Suber ◽  
Cork Oak ◽  
Wood Moisture Content ◽  
Wood Moisture ◽  
Vessel Size ◽  
Xylem Structure ◽  
Crown Size

Azimuthal variations in xylem conductivity and transpiration can occur in trees and may be due to heterogeneity in environmental factors. In cork oak (Quercus suber L.), it can be hypothesized that such modifications may be more pronounced because the insulating layer of bark is harvested every 9–10 years, thus cambial cells will be exposed to fluctuations in the microenvironment. To investigate whether xylem structure and water relations differed around the stems of mature cork oak, sap flow per section and xylem structure were measured on the northern (N) and southern (S) sides of nine trees during three months in Portugal, using the Trunk Sector Heat Balance method. Crown size was measured on both sides of each tree and increment wood cores were extracted from the sites where sap flow was measured in five trees. Wood moisture content, earlywood (EW) vessel size and density were measured and theoretical hydraulic conductivity for individual vessels (Lth) was calculated along the N and S stem radial profiles. No significant differences in crown size between the two sides of the tree were found, but sap flow was higher on the S side of the tree in May only. No differences in wood moisture content were observed along the length of each wood core throughout the heartwood. Significant differences in vessel size occurred, with a greater diameter and surface area on the N side of the tree, and consequently Lth was significantly greater. These conduit diameters on the S facing side of the tree may be smaller in response to a combination of signals and trade-offs due to the heterogeneous air and soil environment around the tree.

Characterization of Cork Oak (Quercus Suber) Wood Anatomy

IAWA Journal ◽  
2009 ◽  
Vol 30 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Vicelina B. Sousa ◽  
Sofia Leal ◽  
Teresa Quilhó ◽  
Helena Pereira
Keyword(s):  
Mediterranean Area ◽  
Vessel Diameter ◽  
Structural Features ◽  
Quercus Suber ◽  
Cork Oak ◽  
Oak Wood ◽  
Cork Production ◽  
Water Conduction ◽  
The Mediterranean ◽  
Perforation Plates

The cork oak (Quercus suber L.) is important for ecological and socioeconomic sustainability and nature conservation in the Mediterranean area. Anatomical and structural features of cork oak wood were characterized at two sites in Portugal, including never-debarked trees and trees under cork production. Cork oak wood showed semi-ring porosity, solitary vessels with simple perforation plates, and large rays. Vessels were arranged in a diagonal to radial pattern, larger and more abundant in earlywood, and gradually decreasing in intermediate and latewood. In trees under cork production vessel distribution and frequency were altered, with more frequent and smaller pores, and a less distinct porosity pattern. Vessel diameter, element length and frequency were 133 ± 49 μm, 433 ± 103 μm and 2.9 ± 0.5 vessels/mm2 for never-debarked trees and 139 ± 50 μm, 341 ± 100 μm and 5.1 ± 1.5 vessels/mm2 for debarked trees. Multiseriate ray width ranged 0.15–1.04 mm, and uniseriate ray height 9.1–791.3 μm. Fibres had a mean length of 1.15 ± 0.20 mm. Vasicentric tracheids were frequent. Tyloses and crystals were commonly present. The anatomical features of cork oak wood favour water conduction and mechanisms of drought adaptation to the Mediterranean climate. The wood can also adapt to cork removal.

scholarly journals Effect of Water Deficit on Gas Exchange Responses to Intercellular CO2 Concentration Increase of Quercus suber L. Seedlings

2019 ◽  
Vol 12 (1) ◽  
pp. 73
Author(s):  
Mokhtar Baraket ◽  
Sondes Fkiri ◽  
Ibtissam Taghouti ◽  
Salma Sai Kachout ◽  
Amel Ennajah ◽  
...  
Keyword(s):  
Water Deficit ◽  
Intercellular Co2 Concentration ◽  
Co2 Concentration ◽  
Quercus Suber ◽  
Cork Oak ◽  
Concentration Increase ◽  
Effect Of Water ◽  
Negative Effect ◽  
Photosynthetic Responses ◽  
Intercellular Co2

In north Tunisia, the Quercus suber L. forests have shown a great decline indices as well as a non-natural regeneration. The climate changes could accentuate this unappreciated situation. In this study, the effect of water deficit on physiological behavior of Quercus suber seedlings was investigated. Photosynthetic responses of 15 months old Cork oak seedlings grown for 30 days under 40% and 80% soil water water content (control) were evaluated. Results showed a negative effect of water deficit and a positive effect of the intercellular CO2 concentration increase both on photosynthesis and transpiration. Stomata conductance might play a major role in balancing gas exchanges between the leaf and its environment. Moreover, global warming could negatively affect carbon uptake of Cork oak species in northern Tunisia. Elevated CO2 leaf content will benefit Cork oak growing under water deficit by decreasing both photoysnthesis and transpiration, which will decrease either the rate or the severity of water deficits, with limited effects on metabolism. the results suggest that high intercellular CO2 concentration could increase water use efficiency among Cork oak species.

scholarly journals Linking Cork to Cork Oak Landscapes: Mapping the Value Chain of Cork Production in Portugal

2021 ◽  
Vol 5 ◽  
Author(s):  
Irene Holm Sørensen ◽  
Mario Torralba ◽  
Cristina Quintas-Soriano ◽  
José Muñoz-Rojas ◽  
Tobias Plieninger
Keyword(s):  
Value Chain ◽  
Global Scale ◽  
Quercus Suber ◽  
Agroforestry Systems ◽  
Cork Oak ◽  
Oak Trees ◽  
Cork Production ◽  
Central Portugal ◽  
Characteristic Features ◽  
Farming Landscapes

Traditional farming landscapes in South and Central Portugal, known as montados, are affected by global socio-economic and biophysical pressures, putting the sustainability of the systems in jeopardy. Cork oak trees (Quercus suber L.) are characteristic features of these complex agro-silvo-pastoral agroforestry systems, delivering a globally important product, cork. The increasingly distant, global scale of decision making and trade can consequently be observed on the local, landscape, scale. In this study, we use a value chain approach to test the concept that landscape products can ensure sustainable management of the landscape of origin. We interviewed agents—cork producers, intermediaries, industrial transformers, and winemakers—about the challenges they perceived in the business and how these were connected to the landscape of origin. We illustrate the network of agents and sub-actors involved in the sector and highlight the most prominent concerns. We conclude that this approach can reveal the major points for determining the future of the montado, and we suggest that collaboration amongst value chain agents can be a pathway to landscape sustainability.

Sign in / Sign up

Export Citation Format

Share Document