Comparative analysis of growth traits and wood properties of Catalpa fargesii f.duclouxii(Huangxin)and Catalpa fargesii f.duclouxii
[Objective]This study aimed to provide a scientific foundation for the enhancement,proce-ssing,and utilisation of Catalpa fargesii f.duclouxii(Huangxin),by comparing growth characteristics,wood properties,and fibre morphological types of C.duclouxii(Huangxin)against Catalpa fargesii f.duclouxii,and evaluating the wood quality of C.duclouxii(Huangxin).[Method]Samples from three 25-year-old C.duclouxii and three 25-year-old C.duclouxii(Huangxin)specimens were collected from identical habitats.Growth metrics,such as the diameter at breast height,were recorded through trunk ana-lysis.Microstructural characteristics and anatomical structure indices-including fibre length,width,cell wall thickness,wall-to-cavity ratio,and cavity diameter ratio-of the heartwood(the 10th annual ring)and sap-wood(the penultimate annual ring)were observed under a microscope and determined for both species.In accordance with national standard(GB/T 1927.2-2021),the timber properties of both species were assessed,which include physical metrics(density,dry shrinkage)and mechanical metrics(hardness,ulti-mate compressive strength parallel to grain,tensile strength parallel to grain,bending strength,modulus of elasticity in bending,cleavage strength,impact bending strength)and colour indices(brightness value L,and hue values a*,b*).Data were analysed with SPSS and Sigma Plot.[Result]① Both C.duclouxii(Huangxin)and C.duclouxii were in their rapid growth phase at the age of 25,with the growth rate of C.duclouxii(Huangxin)being marginally lower than C.duclouxii.The heartwood of C.duclouxii(Huangxin)was yellow-brown,whereas that of C.duclouxii was grey,both comprising over 75％of the tree volume at all height between 0-8 m.② Microstructural analysis revealed that both species are ring-porous woods.Fibre lengths in the heartwood were 805.58 µm for C.duclouxii(Huangxin)and 824.21 pm for C.duclouxii,fiber-to-width ratios of C.duclouxii(Huangxin)and C.duclouxii were both high-er than 35 and wall-to-cavity ratios lower than 1.It indicated that C.duclouxii(Huangxin)was slightly superior to C.duclouxii in fibre morphology.③ Air-dry densities of C.duclouxii(Huangxin)and C.duclouxii were 0.47 and 0.46 g/cm3 respectively,volumetric shrinkages of 0.37％and 0.33％,compre-ssive strengths 43.11 and 40.09 MPa,elastic moduli 11.03 and 10.00 GPa,bending strengths 70.56 and 64.11 MPa,and impact bending strengths 54.70 and 49.88 kJ/m2.Overall,the material properties of C.du-clouxii(Huangxin)were found to be superior to those of Catalpa fargesii f.duclouxii.[Conclusion]Al-though the growth rate of C.duclouxii(Huangxin)was slightly lower than that of C.duclouxii,it sur-passed in wood properties.C.duclouxii(Huangxin)had a high heartwood ratio and a yellow-brown co-lor,which endowed it with significant economic value.
万方数据
维普
