中国森林资源1950—2003年经营状况及问题

根据经营方针、经营特征以及森林数量、质量和结构的变化，中国50多年的森林经营可以划分为森林资源质量恶化和逐步恢复两个阶段。森林经营结果表明，1950—2003年，我国森林资源在采伐利用蓄积量为130.57亿m3的同时，森林面积和蓄积仍有增加，森林经营成绩显著。但是，由于森林经营理论滞后、经营理念重采轻育、分类经营界定不清晰、结构调整目标不明确、经营以木材需求为核心，忽视了森林的自然生长发育规律等问题，导致森林结构发生了较大变化，天然林面积比重下降了30.6%，蓄积比重下降了9.4%；用材林面积和蓄积比重减少到46.52%和45.57%；森林低龄化明显，幼中龄林面积比重占67.9%；针叶林面积和蓄积也有不同程度的减少。由于森林采伐利用强度较大，择伐周期较短，森林质量在第二阶段虽有所恢复，但仍然较差。林分单位蓄积平均仅为84.73 m3/hm2，低郁闭度（0.2～0.4）面积占34.41%，平均胸径为13.8 cm，生长发育状况良好的面积仅占42.22%；同时，虽然人工林面积较大，但中幼龄林面积比重达77.40%，单位面积蓄积仅为46.59 m3/hm2。因此，新世纪的森林经营必须依据森林资源现状，对经营理论与实践合理扬弃，优先解决经营理论、产权优化、分类界定和经营技术等问题。 

Forest management conditions and problems from 1950 to 2003 in China

Two phases, deterioration phase and instauration phase, were marked off according to changes of forest management policy, characteristics, forest quantity, quality and structure in China. From 1950 to 2003, 130.57×10.8m3 timber was harvested and forest area and volume rose. Due to the underdeveloped forest philosophy, such as more importance to cutting and slight to cultivating, an unclear definition for forest classification management, an undefined aim for management structure adjustment, a focus of timber request and an ignorance of natural laws of forest growth, it makes the forest structure changed greatly with the proportion of natural forest area decreased by 30.6%, natural forest volume decreased by 9.4%, timber forest area decreased to 46.52%, timber forest volume decreased to 45.57%. The proportion of young and middle-aged forest are