不同经营模式下降低马尾松纸浆生产成本的育种目标

Breeding Objectives for Reducing Pulp Production Costs of Masson Pine under Different Management Models

在构建不同经营模式马尾松未漂硫酸盐浆(UBMKP)生产成本函数的基础上,尝试研究目标性状木材产量(V)、木材密度(SG)和制浆得率(PY)的经济权重及对育种的重要性,建立相应的育种目标和选择方程。研究发现,目标性状对育种的重要性与纸浆生产的成本构成有关。对包括从纸浆林营建到制浆等阶段的林纸一体化的造纸企业,由于与PY和SG有关的木材收获、运输和制浆等未来成本分量在纸浆生产总成本中所占比例很高,因而PY和SG对降低纸浆生产成本的重要性较高,随着贴现率的提高,PY和SG的重要性下降。对于仅靠生产和出售木材的纯林业生产系统,V是最重要的育种目标,可较少考虑SG和PY。敏感性分析指出,对于林纸一体化的企业,成本构成、贴现率和轮伐期等变量对选择决策影响较小。对纸浆生产不同经营模式下育种经济效果的分析表明,若入选率为10%,经过第1代遗传改良,生产能力为2×105t·a-1UBMKP的纸厂每年可获得657.6～746.8万元的额外效益。

Production cost functions for unbleached masson pine kraft pulp (UBMKP) under different management models were used to determine the economic weights and value to breeding of standing volume,specific gravity and pulp yield and establish corresponding breeding objectives and index selection equations. It was found that importance of breeding objectives was related to cost structures of pulp production. For the pulp mill from growing trees to the production of UBMKP increasing pulp yield and specific gravity had major effects on reducing production cost,since pulp yield and specific gravity primarily influenced the future costs (harvesting,transport,and pulping). Increasing the discount rate should result in decreasing of importance of pulp yield and specific gravity. For a pure forest production system with no affiliation to pulp mill,the breeder′s attention should be focused on genetic improvement of standing volume,not on specific gravity and pulp yield. Sensitivity analysis indicated that economic weights including component costs,rotation and discount rate had minimal effects on the selection decisions. Economic consequences for breeding of pulp production showed that the first generation improved plantation could be expected to achieve additive annual profit of RMB Yuan 6.6～7.5 million for a pulp company with a mill capacity of 200 000 t and self sufficiency in wood supply. assuming that the ten top trees in every 100 was selected.