湖南省2009年杉木林碳贮存量及未来固碳潜力分析

摘要

Tree biomass data published in literature were derived to generate allometric equations for 5 age classes of Cunninghamia lanceolata (Chinese ifr) and then the equations were used to estimate stand biomass and carbon storage of 5 age classes. Based on stand area of 5 age classes recorded from forest inventory data in 2009, total carbon storage of C. lanceolata forests was determined for Hunan Province and its 14 subordinated prefectural cities. At the same time, we also selected the data in literature as baseline for the stand biomass at different age of C. lanceolata forests under appropriate management. The current status of stand area distribution of 5 age classes was analyzed for C. lanceolata forests in Hunan and normal forest rule was applied to adjust forest area to achieve an ideal stand area distribution. Consequently, potential carbon sequestration in future of C. lanceolata forests in Human was investigated on the condition of appropriate forest management and ideal area structure of forest age classes after adjustment. The results showed that stand carbon storage of C. lanceolata forests in 2009 accounted for 0.50~227.01 t/hm2, with average stand carbon storage ranging from 5.94 t/hm2 for young forests to 147.25 t/hm2 for over mature forests. Total carbon storage of C. lanceolata forests in Hunan reached 52.16 × 106 t, of which the lowest was 0.42×106 t in Xiangtan City and the highest was 11.97 × 106 t in Huaihua City. Total carbon storage in C. lanceolata forests showed an increasing tendency from 1.94 × 106 t for young forests to 13.12 × 106 t for over mature forests. If appropriate forest management was implemented, total carbon storage of C. lanceolata forests in Hunan would increase to 103.83 × 106 t,which was about two times of the value in 2009. After stand area adjustment for age classes, total carbon storage C. lanceolata forests in Hunan would go up tp 81.10 × 106 t (about 1.5 times of the values in 2009), with ranging from 1.91 × 106 t for young forests to 47.37 × 106 t for over mature forests. Therefore, C. lanceolata forests in Hunan have a great potential to increase carbon sequestration in future if sustainable forest management is carried out. Our ifndings provide useful information for C. lanceolata forest management and ecosystem functions division in Hunan Province.%利用文献数据建立杉木不同龄组（幼龄林、中龄林、近熟林、成熟林和过熟林）的生物量相对生长方程，计算杉木各龄组林分的平均生物量和碳贮量。根据2009年湖南省森林资源数据，估算湖南省及各地市（州）杉木林总生物量和碳贮存总量。从文献中选择生长较好的杉木林作为合理经营状态林分，分析该状态下杉木林各龄组的林分生物量，同时针对湖南省杉木林各龄组的面积分布现状，调整龄组面积结构，估算合理经营状态下和调整龄组结构后杉木林的碳贮量，分析湖南省杉木林的未来固碳潜力，为湖南省杉木林合理经营和生态功能区划提供科学依据。结果表明：2009年湖南省杉木林林分的碳贮量为0.50～227.01 t/hm2，林分平均碳贮量从幼龄林的5.94 t/hm2增加到过熟林的147.25 t/hm2。全省杉木林碳贮存总量为52.16×106 t，其中湘潭市杉木林碳贮量最低，为0.42×106 t，怀化市的最高，为11.97×106 t。杉木幼龄林的碳贮存总量最小（1.94×106 t），过熟林最大（13.12×106 t）。如果采取合理经营措施，湖南省杉木林碳贮存总量可增加到103.83×106 t，约为目前杉木林碳贮存总量的2倍。杉木林龄组结构调整后，湖南省杉木林各龄组碳贮量从幼龄林的1.91×106 t增加至过熟林的47.37×106 t，全省杉木林碳贮存总量可增加到81.10×106 t，为目前杉木林碳贮存总量的1.55倍。可见，湖南省杉木林具有较大的固碳潜力，提高林分单位面积生产力和调整全省杉木林龄组面积结构是增加森林固碳潜力的有效途径。