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利用磐安县2001年区划界定的28 190 hm2重点公益林作为研究对象,通过2001年和2012年不同林地类型生产力指标与森林生态状况指标的对比,运用数学方法测算出全县重点公益林评价指标值,评价与分析了全县重点公益林森林资源质量变化情况;活立木总蓄积由2001年81.5×104m3增加到2012年158.5×104m3;单位面积蓄积量由2001年30.53 m3/hm2增加到2012年59.88 m3/hm2;阔叶林及针阔混交林面积由2001年4 876 hm2增加到2012年13 547 hm2。群落结构复杂、乔灌草层次完整的公益林面积大幅增长,说明磐安县公益林林种树种结构趋于优化,生物多样性日益丰富,森林的生态功能与社会功能显著增强。全县公益林中针叶林所占比重过大,阔叶林与针阔混交林占比仍过少,中幼林面积过多,成过熟林面积过少。
Based on the comparison of 28 190 hm2 key public welfare forests defined by Pan’an County in 2001 and the comparison of forest productivity index and forest productivity index of different forest types in 2001 and 2012, the paper evaluates the evaluation index of key public welfare forests , Evaluated and analyzed the change of forest resource quality of the key public welfare forests in the county; the total volume of live standing trees increased from 81.5 × 104m3 in 2001 to 158.5 × 104m3 in 2012; the volume per unit area increased from 30.53 m3 / hm2 in 2001 to 59.88 in 2012 m3 / hm2. The area of broad-leaved forest and coniferous-broad-leaved mixed forest increased from 4 876 hm2 in 2001 to 13 547 hm2 in 2012. Community structure is complex, and the area of non-commercial forest with a complete hierarchy of trees, shrubs and grass is increasing. This shows that the tree species structure of commonweal forest in Pan’an County tends to be optimized and biodiversity is enriched day by day. The ecological functions and social functions of forests are significantly enhanced. The proportion of coniferous forests in public welfare forests in the county is too large. The proportion of broad-leaved forests and coniferous and broad-leaved mixed forests is still too small. The area of medium-sized and young forests is too large and the area of mature coniferous forests is too small.