树种组成对北亚热带11年生常绿阔叶人工林碳储量的影响

以中国北亚热带退化灌木林改造而来的木荷-青冈栎混交林和杜英纯林为对象,研究树种组成对常绿阔叶人工林生态系统碳储量的影响。结果表明:(1)退化灌木林改造成两种人工林生长11年后,生态系统植被、土壤碳储量均显著增加;植被碳储量的增加主要来自乔木层。(2)两种人工林碳积累能力有差异。杜英林植被碳储量比木荷-青冈栎林高99.4%,其中杜英林的乔木层碳储量比木荷-青冈栎林高27.75t·hm-2,是后者的2倍;杜英林土壤有机碳储量(0~50cm)显著高于木荷-青冈栎林10.17t·hm-2,其中在0~10、20~30cm土层杜英林均显著高于木荷-青冈栎林。研究表明,退化灌木林人工改造成常绿阔叶林后生态系统碳储量显著增加,杜英纯林碳蓄积能力明显高于木荷-青冈栎混交林,说明在以增加碳储量为目的的退化生态系统改造过程中,树种选择非常重要。

Effects of Tree Species Composition on Carbon Storage of 11 Years Old Evergreen Broad leaved Plantations in North Subtropical Areas of China

Taking Schima superba Cyclobalanopsis glauca mixed plantation (SP) and Elaeocarpus sylvestris pure plantation (EP) both plantations were transformed from degraded shrub forest (DF) in north subtropical areas of China as test objects,we studied the effects of species composition on ecosystem carbon storage of broad leaved plantations.(1)Both the vegetation and soil carbon storage significantly increased after the DF was transformed into broad leaved plantations.The increases of vegetation carbon storage appeared mainly in arborous layers.Compared with DF,the soil carbon storage of SP and EP was significantly increased in each interval of 0-50 cm depth,respectively.(2)The vegetation carbon storage was higher in EP than that in SP,with an increase of 99.4%.Compared with SP,the carbon storage in arborous layer of EP was 27.75 t·hm^-2 higher,which was as twice as that of SP.The soil carbon storage in EP was 10.17 t·hm^-2 higher than that in SP,with a significant difference.In addition,the soil carbon storage in each interval of 0-50 cm depth of EP was higher than that in SP,with significant differences in 0-10 cm and 20-30 cm layer.To sum up,the total carbon storage of degraded shrub forest was significantly increased after transformed into evergreen broad leaved plantation and EP had greater ability of carbon accumulation than SP.Results from the present study suggested that the choice of tree species would be important during the restoration of degraded ecosystems with the aim of enhancing ecosystem carbon storage.