The Influence of Age on the Wood Properties of Paulownia tomentosa (Thunb.) Steud.

Abstract

Forests in Portugal are highly dependent on a short number of wood species, and new species with higher profitability are needed. The Paulownia species has generated great interest due to its fast-growing and relatively good wood properties. However, environmental factors have shown that Paulownia grows differently in each case. This study intends to determine the properties of young Paulownia trees from Portuguese plantations to determine the best age to cut the trees according to their use. The chemical composition (extractives in dichloromethane, ethanol and water, lignin, α-cellulose, and hemicelluloses), heating value, elemental analysis (CHNO), inorganic elements and thermogravimetric analyses (TGA), and the most important mechanical and physical properties (density, MOE, bending strength, water absorption equilibrium, moisture content, and dimensional changes) were determined for 1-, 3-, and 5-year-old trees. The results show that, chemically, the extractives increased while hemicelluloses decreased with age, and no trend was found for lignin and α-cellulose. The physical and mechanical properties increased with age, except for the MOE and bending strength. The 5-year-old samples presented the best features for pellet production, namely, calorific power, elemental composition CHNO and sulfur, and inorganic elements.

Radial Variability of Selected Physical and Mechanical Parameters of Juvenile Paulownia Wood from Extensive Cultivation in Central Europe—Case Study

“…Various studies of the wood of Paulownia are based on the material obtained from very young trees to find the best valorization path [ 60 ]. Perhaps for this reason there is little information in the literature about the radial variation in the properties of the wood.…”

Physical and Mechanical Properties of Paulownia tomentosa x elongata Sawn Wood from Spanish, Bulgarian and Serbian Plantations

“…This value is lower for Paulownia wood from Hungary at 246 kg/m 3 [1] or from Spain at 215 kg/m 3 [36]. Estevez et al [11] reported a value of 460 kg/m 3 for Portuguese Paulownia wood, which is even higher than the average density of spruce with 430 kg/m 3 according to [39].…”

“…Nevertheless, the optimum soil and climate conditions and the most suitable plantation sites have not been clarified yet, and at present there is no best practice guidance for forest farmers who intent to manage Paulownia plantations [10]. This lightweight tree species gained interest worldwide and is named a miracle tree, empress tree or princess tree [11], due to its high rate carbon absorption and rated as fast-growing energy crop with C4 photosynthesis [12], easy processability, and good fire resistance [13].…”

Qualitative and quantitative anatomical characteristics and radial variation of major cell components in Paulownia tomentosa wood grown in Korea

“…The Paulownia tree, also known as princess, empress, or royal tree, has gained significant interest worldwide owing to its fast growth rate. This tree can produce a large quantity of wood in a short period and can be used as timber within 5 to 20 years after planting (Icka et al 2016;Esteves et al 2022). Moreover, Paulownia trees can absorb approximately 22 kg of carbon dioxide and emit 6 kg of oxygen annually, generating thousands of cubic meters of clean air.…”

“…Moreover, Paulownia trees can absorb approximately 22 kg of carbon dioxide and emit 6 kg of oxygen annually, generating thousands of cubic meters of clean air. This is a high rate of carbon absorption for a fastgrowing tree species (Touraev 2006;Angelov 2010;Esteves et al 2022).…”