Cross-field pitting characteristics of compression, lateral, and opposite wood in the stem wood of Ginkgo biloba and Pinus densiflora

Abstract

AbstractThe characteristics of cross-field pitting among compression wood, lateral wood, and opposite wood, in the stem woods ofGinkgo bilobaandPinus densiflorawere investigated with optical and scanning electron microscopy. InGinkgo biloba, compression wood exhibited piceoid pits, while lateral and opposite wood exhibited cupressoid pits. The compression wood ofPinus densifloraexhibited cupressoid pits and piceoid pits, while lateral wood and opposite wood exhibited pinoid and window-like pits in the cross-field. In both species, compression wood yielded the smallest pit number among each part, while opposite wood yielded the greatest pit number per cross-field. Cross-field pitting diameters of compression wood and opposite wood were significantly smaller than lateral wood inGinkgo biloba, while the cross-field pitting of compression wood was the smallest inPinus densiflora. Radial tracheid diameter of compression wood was slightly smaller than lateral and opposite wood inGinkgo bilobaand significantly smaller than lateral and opposite wood inPinus densiflora. In conclusion, the cross-field pitting type, pit number, and cross-field pitting diameter could be used to identify reaction wood in the stem wood ofGinkgo bilobaandPinus densiflora.