Influence of region of provenance and climate factors on wood anatomical traits of Pinus nigra Arn. subsp. salzmannii

Abstract

Region of provenance is defined as an area with uniform ecological conditions where stands with similar phenotypic or genetic features are found. This study assesses the effect of differing climate conditions of eight Spanish regions of provenance of Pinus nigra Arn. subsp. salzmannii on earlywood anatomical traits measured in samples from basal discs from mature trees. Results showed that variation in wood biometry between provenances was high and more pronounced than intrapopulation variation. When comparing P. nigra with other Mediterranean pines, high intertracheid wall strength values are associated with better adaptation of pines to arid conditions. However, the intraspecific variations of this parameter in P. nigra did not follow the same pattern, due to the influence of mechanical support requirements. Trees subject to greater aridity were characterised by short tracheids, apparently resulting from their poorer growth, and high frequency of rays and ray parenchyma cells, which would allow trees to store greater amounts of starch, which is the source of metabolites invested in minimising the limitations imposed by water stress. Severe winter cold spells were strongly associated with high axial resin canal frequency and large radial resin canals, creating a powerful, preformed defence system. Increased tracheid lumen involved an increase in the size of bordered pits, favouring sap flow between tracheids, in addition to an increase in the maximum diameter of cross-field pits, favouring the flow of water and metabolites between the axial and radial systems. The high influence of region of provenance on structural variation in P. nigra shows the importance of provenance in the selection of seed origin for reforestation.

Influence of climate variables on resin yield and secretory structures in tapped Pinus pinaster Ait. in central Spain

“…Ethylene appears to play a key role in linking exogenous factors that induce ethylene production and resin canal formation. The two principal factors inducing ethylene production are extreme temperatures and drought (Abeles et al, 1992;Esteban et al, 2012). This could explain the correlation observed between the frequency and area per mm 2 of axial canals and the climate variables related to extreme temperatures and drought: cumulated water deficit, maximum temperatures and number of certain frost months in the previous year ( Table 3).…”

Effects of Drought on Xylem Anatomy and Water-Use Efficiency of Two Co-Occurring Pine Species

“…The conductivity of tracheids depends partially on the characteristics, number and size of their pits [18,61] as well as their lumen diameter (Hagen-Poiseuille law [62]) and cell wall thickness [19]. The number and diameter of pits in P. sylvestris and P. nigra increase with lumen diameter [63,64]. A more efficient xylem would result from decreased resistivity due to wider lumens and wider and more abundant pits.…”

“…At population level, both P. sylvestris [63] and P. nigra [64] in the Iberian Peninsula develop thick cell-walls and narrow lumens at drier locations. Here, our results suggest that, at interannual scale, the pattern is opposite, i.e., drought induces thinner cell walls but wider lumens, in accordance with results from other species and sites [25,57,58].…”

“…Allocating more carbohydrates to mycorrhiza and root growth, storage or needles [9,[11][12][13] offer the advantage of a faster recovery or the possibility to withstand longer periods of drought and may also be key strategies to ensure survival in long-lived plants [9,70]. Also, P. nigra has a higher frequency of rays and parenchyma than P. sylvestris [63,64] which are related to higher potential for storing non-structural carbohydrates and water contributing to a faster recovery after stressful conditions [74]. Our result of P. nigra reducing wall thickness more than P. sylvestris could be due to a greater investment to reserves, defenses or growth of other parts of the plant that allows it to recover better after drought.…”

Effect of Provenance and Climate on Xylem Anatomy of Haloxylon Ammodendron (C. A. Mey) Bunge in the Gurbantunggut Desert, China

“…Generally, ray tissues are related to the storage and transport of water and nutrients. The higher ray frequency means that the xylem can accumulate more water and starch, and the starch can provide metabolites to reduce the impact of water stress (Esteban et al, 2012). For example, Acacia tortilis subsp.…”