Wood properties related to pulp and paper quality in two Macaranga species naturally regenerated in secondary forests, Central Kalimantan, Indonesia

The utilization of wood resources from unutilized fast-growing tree species found in secondary forests was investigated by studying the wood properties, including anatomical characteristics, of two Macaranga species—M. bancana and M. pearsonii—growing naturally in secondary forests in Central Kalimantan, Indonesia. Several wood properties related to pulp and paper quality were also evaluated, including the Runkel ratio, Luce's shape factor, flexibility coefficient, slenderness ratio, solid factor, and wall coverage ratio. The mean basic density of these two species ranged from 0.23 to 0.31 g cm, while the mean values of vessel diameter, vessel element length, fiber diameter, fiber wall thickness, and fiber length ranged from 126 to 192 μm, 0.88 to 1.19 mm, 24.5 to 29.8 μm, 0.99 to 1.14 μm, and 1.42 to 1.69 mm, respectively. The lignin content of M. bancana and M. pearsonii wood was 27.2 and 28.0%, respectively. Almost all wood properties related to pulp quality showed better values than those reported for Acacia and Eucalyptus species, although sheet density of paper might be lower due to higher solids factor and possibility of occurrence of vessel picking was probably higher due to longer vessel element length and larger vessel diameter. Based on the results, the wood from these two Macaranga species can be used as pulpwood.