Determination of Pulp and Paper Making Suitability Indices of Some Nigerian Species of Leguminosae: Caesalpinoideae

Uncontrolled felling of trees for domestic and industrial uses is fast depleting the tropical forests and has led to a continued exploitation of Gmelina arborea Roxb. plantations for fuel wood and timber, a development that is threatening the ecosystem and the survival of the pulp and paper making (PPM) industries in Nigeria. This study proposes an objective method for selecting hardwood species for PPM by statistically comparing the available anatomical and other related data in the reference wood (i.e G. arborea Roxb.) with those of alternative hard wood species. (i.e twelve Nigerian species of Caesalpinioideae ). Mature stem branches (8-12cm diameter ) of twelve species , representing nine genera of the family were collected at various locations in Oyo state. A similar stem branch of G. arborea Roxb. was collected as a standard raw material for pulp and paper making. Using conventional wood anatomical techniques, nine qualitative and twenty quantitative characters were determined. The means of all the quantitative characters were compared by conducting a One-way classification analysis of variance using the version 17.0 SPSS package. Also t-test conducted indicated a significant difference between data from each of the species of Caesalpinoideae and that of G. arborea. Based on the result of the comparison, a numeric value by which the PPM potential of the alternative hardwood species was precisely defined. Results show that the woods of Caesalpinioideae species investigated are highly suitable wood resources for PPM, virtually all the species can be said to be among the best substitutes for G. arborea each being at least 75% suitable for papermaking in comparison with G. arborea. The Caesalpinioideae species investigated in order of their preferences for PPM are listed as Tamarindus indica (1.5426), Delonix regia (1.2781), Brachystegia eurycoma (1.1801), Senna sieberiana (1.1565), Bauhinia rufescens (1.1119), Afzelia africana (1.0836), Senna siamea (1.0647), Danielia ogea (1.0400), Piliostigma thoningii (0.9431), Detarium senegalensis (0.9114), Danielia oliveri (0.8423) and Caesalpinia pulcherima (0.7562).