桤木人工林的碳密度、碳库及碳吸存特征

Carbon Density,Carbon Stock and Carbon Sequestration in Alnus cremastogyne Plantation

对不同年龄阶段桤木人工林生态系统碳密度、碳库和碳吸存的研究结果表明:桤木各器官的碳密度算术平均值随年龄的增长而增加,5,8和14年生的分别为478.8,485.7和495.8g·kg-1,变异系数在0.25%～9.58%之间,不同器官碳密度由高至低排序大致为:树干>树枝>树叶>树根>树皮,林下植被各组分和死地被物的碳密度随着林龄的变化规律不明显,土壤层(0～60cm)平均碳密度也随着林龄的增长逐渐增加,且在垂直分布上随着土层深度的增加而逐渐下降。不同器官的碳贮量与其生物量成正比例关系,随着林龄增长,乔木层碳贮量的优势逐渐增强,从5年生的25.88t·hm-2增加到14年生的49.63t·hm-2。桤木人工林生态系统的碳库主要由植被层、死地被物层和土壤层组成,按其碳库大小顺序排列为:土壤层>植被层>死地被物层,5,8和14年生桤木林生态系统中的碳库分别为95.89,122.12和130.75t·hm-2,土壤碳贮量占整个生态系统碳库的59.42%以上,且随着林龄增长,地上部分与地下部分碳贮量之比有逐渐下降的趋势,5,8和14年生桤木年净固定碳量分别6.51,6.26和7.82t·hm-2a-1。湖南省现有桤木林植被碳库为2.8034×106t,为其潜在碳库的47.51%。

Carbon density,carbon stock and sequestration was made in Alnus Cremastogyne plantation ecosystem. The result shows that the arithmetic average carbon density of different organs was 478. 8 g·kg -1 for the 5-year-old plantation, 485. 7 g·kg -1 for the 8-year-old stand and 495. 8 g·kg -1 for the 14-year-old plantation,and the variation coefficient ranged form 0. 25% to 9. 58% . The carbon densities of different organs varied in the following order： stems branches leaves roots bark. No obvious trends were detected for the carbon densities in different groups of under-storey of plants or the duff layer as the forest aged. The soil carbon density increased along with the stands aged and declined with the soil depth in the different age classes Alnus cremastogyne plantation. The carbon storage in different oranges was positively related to the biomass of corresponding organs. Superiority of carbon storage in the trees gradually strengthens as the forest stands aged,carbon storage of the trees had gone up from 25. 88 t·hm^-2 for the 5-year-old to 49. 63 t·hm^-2 for the 14- year-old plantation. The carbon stock of Alnus cremastogyne plantation ecosystem was mainly consisted of three sections, that was the trees,the litter and the soil,cremastogyne plantation was 95. 89 t·hm^-2at the 5-year-old,122. 12 t·hm^-2at the 8-year-old and 130. 75 t·hm^-2at the and the order of whose carbon stock could be ranked as follow： the soil〉 the trees the litter. Carbon stock of Alnus 14-year-old. Carbon storage in forestlands soil layer （0 ～ 60 cm） accounted for more than 59. 42% of carbon storage in the whole ecosystem,the ratio of carbon storage of aboveground to that of underground deceased as the Alnus cremastogyne forest age growth. The annual carbon amount of the 5-year-old,the 8-year-old and the 14-year-old Alnus cremastogyne plantation was respectively 6. 51,6. 26 and 7. 82 t·hm^-2·a ^-1. Extant carbon storage of Alnus cremastogyne plantation in Hunan province was up to 2. 803 4 × l0^6 t,accounting for 47. 51% of its potential carbon storage.