浙中不同林龄人工杉木成过熟林碳储量全面估算

Comprehensive carbon storage inventory of mature and overmature Chinese fir(Cunninghamia lanceolata)plantations with different ages in central Zhejiang Province,eastern China

杉木人工林的碳储量虽被广泛研究,但常因含碳率应用欠妥(未考虑林龄和器官的影响),或植物生物量估算不全面(未估算乔木层伴生植物和木质残体的生物量),导致现有研究结果存在较大误差.以浙中金华北山4个林龄(28、37、42和52年)人工杉木成过熟林为研究对象,测定分析不同林龄杉木人工林所有植物组分和土壤的碳含量特征,并全面估算4个林龄人工杉木成过熟林的生态系统碳储量.结果表明:植物组分全碳含量变异较小而土壤有机碳含量变异较大;树龄和器官对杉木全碳含量具有显著影响;土壤有机碳含量随土层深度的增加而降低,且受林龄显著影响.4个林龄人工杉木成过熟林生态系统碳储量表现为42年(160.58 t/hm^(2))>28年(146.70 t/hm^(2))>52年(144.84 t/hm^(2))>37年(129.28 t/hm^(2)),平均为145.35 t/hm^(2),各林龄杉木人工林生态系统碳储量的差异不显著;植物活体(61.27 t/hm^(2))、土壤(73.41 t/hm^(2))以及凋落物和木质残体(10.67 t/hm^(2))的碳储量分别占生态系统碳储量的42.3%、50.2%和7.5%.本研究表明与我国亚热带其他地区人工杉木成过熟林相比,浙中金华北山人工杉木成过熟林属低碳储量森林.

Although carbon storage in Chinese fir(Cunninghamia lanceolata)plantations has been widely investigated,the results of existing studies are inaccurate because of the improper examination of carbon content(without considering the effects of stand age and organs)and incomplete estimation of plant biomass(without estimating the biomass of associated plants in the tree layer and woody debris).In the present study,we measured and analyzed the carbon content characteristics of all plant compartments and soils in four C.lanceolata plantations of different ages(28 a,37 a,42 a,and 52 a)in the Beishan Mountains of Jinhua,central Zhejiang Province,and comprehensively estimated their ecosystem carbon storage.The results showed that the variations in the total carbon content of plant compartments were small,but those in the soil organic carbon content were large.Tree age and organ composition significantly affected the total carbon content of C.lanceolata.Soil organic carbon content decreased with increasing soil depth and was significantly affected by forest age.The ecosystem carbon storages of the four mature and overmature C.lanceolata plantations changed in the order of 42 a(160.58 t/hm^(2))>28 a(146.70 t/hm^(2))>52 a(144.84 t/hm^(2))>37 a(129.18 t/hm^(2)),with an average of 145.35 t/hm^(2).No significant differences in ecosystem carbon storage were observed among the four plantations.The carbon storages of living plants(61.27 t/hm^(2)),soils(73.41 t/hm^(2)),and litter and woody residues(10.67 t/hm^(2))accounted for 42.33%,50.22%,and 7.46%of the ecosystem carbon storage,respectively.Compared with mature and overmature C.lanceolata plantations in other subtropical areas of China,those in the Beishan Mountains of Jinhua,central Zhejiang Province,are low carbon storage forests.