The pulping and papermaking characteristics of youngL.gmelini andB.platyphylla

5, 10, 15, and 20 year oldLarix gmelini andBetula platyphylla were used as pulping raw material in the research. The examination of youngL. gmelini andB. Platyphylla fibrous structures showed that the fiber length and ratio of length to width of 5 years oldL. gmelini noticeably differed from that of matureL. gmelini. but that of 5 year oldB. platyphylla were nearby equal to that of matureB. platyphylla. The research results indicated that 15 years oldB. platyphylla and 20 year oldL. gmelini were best suited to pulping among the eight experimental raw materials; 10 years oldB. platyphylla and 15 year oldL. gmelini were optimal to the ratio of beating degree increment and corresponding beating time. The pulp characteristics of 15 year old B. platyphylla and 20 year oldL. gmelini were similar to those of mature wood, and it was feasible to consider 15 years toB. platyphylla and 20 years toL. gmelini as their rotation period; 10 years and 15 years as their thinning cycles for the papermaking forest base.