Physical, chemical and mechanical wood properties of Pinus nigra growing in Portugal

Abstract

& Key message The wood of Pinus nigra populations planted in Portugal, comparatively to Pinus pinaster, has higher total extractive content, lower Klason lignin and H/G ratio, and similar mechanical properties, presenting advantages for industrial purposes. & Context P. nigra was used in the reforestation of mountainous areas in Portugal, but its wood chemical and mechanical properties were never studied. & Aims This work intends to evaluate the chemical and mechanical wood properties of the P. nigra populations planted in Portugal, to relate these properties with previously characterised physical features and to compare these data with other European P. nigra stands and species, namely, P. pinaster. & Methods Wood chemical and mechanical properties were analysed in 90 trees from six Portuguese sites, using near-infrared (NIR) spectrometry and the three-point bending test. & Results The wood of the P. nigra populations planted in Portugal presented average values of total extractive content = 9.4%, Klason lignin = 26.69%, MOR Rad = 14.93 MPa and MOE Rad = 1200.98 MPa. Ring density showed no significant correlation with ring width. & Conclusion The P. nigra populations planted in Portugal presented qualitative and quantitative properties similar to P. pinaster wood, the main resinous species in Portugal. Facing the lack of raw material for wood industry due to frequent forest fires in the Mediterranean region, P. nigra could be used to reforest mountainous areas of those regions.

Pinus nigra extractives analysis for green growth

“…From all the above data, it is concluded that the largest number of extractives were found in heartwood and bark, as expected. The results are in agreement with those of other researchers, compared with other species as well [16] [21] [23]. Compounds such as ethyl oleate, phthalic acid, borneol, linoleic acid, propenoic acid, and diethyl phthalate were detected in great amounts.…”

“…laricio at the analytical and pilot scale. Wood of P. nigra populations were investigated by Dias et al [16], planted in Portugal, resulted that the average values of total extractive content was at 9.4%. P. sylvestris and P. nigra extracts were chemically analyzed by Vek et al [17] and the inhibitory effect of purified pinosylvins and crude hydrophilic extracts was tested against growth of the white and brown-rot fungi with the in vitro antifungal assay.…”

Maritime Pine, Its Biological and Silvicultural Traits for the Basis of Natural Resources: An Overview

“…Even so, these values for P. pinaster are lower than those reported for the P. sylvestris (10.7-15.4%) and P. n i g r a wood (6.6-12.9%) growing in Portugal [115,117]. In terms of the use of P. pinaster wood, these high extractive values give it some natural resistance to biodegradation (but do not prevent the need to apply preservative products in situations of outdoor use) but may cause some problems in surface finish operations.…”

“…The usual air-dry wood density values of approximately 0.566 g/cm 3 in 30-year-old trees are worth mentioning [156], but which can reach average values of 0.657 g/cm 3 at 70 years old [150]. These values are identical to those of P. nigra (0.588 ± 0.096 g/cm 3 ) [116,117] and P. sylvestris (0.588 ± 0.101 g/cm 3 ) [114,115] with identical ages and growing in Portugal, but higher than P. sylvestris wood from Sweden, France and the Czech Republic (0.391-552 g/cm 3 ) [157][158][159][160], Picea abies (0.410-516 g/cm 3 ) [157], and Abies balsamea (0.351 g/cm 3 ) [161].…”

“…Numerous studies carried out with resinous species in Portugal and Spain have repeatedly demonstrated the absence of correlation between ring width and wood quality characteristics [107][108][109][110][111][112][113][114][115][116][117] which are sufficiently clear to stop fearing, for this species growing in these regions, any hypothetical antagonism between the vigor and the wood quality. In this regard, also worth mentioning the work carried out by Fernandez-Golfin and Diez [107] on the influence of the ring width on the wood density and other physical-mechanical properties of wood in different species (among which P. pinaster).…”