亚热带红壤侵蚀区马尾松不同套种模式生态系统碳平衡

Carbon balance in an interplanting Pinus massoniana stand in subtropical eroded red soil region,China

以福建省长汀县红壤侵蚀区马尾松低效林套种杨梅、无患子、油茶及黄栀子的改造模式林分为研究对象,对林分各组分生物量年净生长量、含碳率及土壤异养呼吸进行定位观测,分析套种模式对低效马尾松林分生态系统碳储量格局及碳平衡的影响。结果表明:杨梅、无患子、油茶、黄栀子和马尾松不同器官含碳率的变化范围分别为41.1%~50.1%、42.2%~50.6%、45.1%~48.9%、44.7%~49.6%和46.1%~51.9%。不同树种同一器官之间的含碳率存在显著差异。马尾松套种杨梅及马尾松套种无患子模式植被层碳储量及年净增碳储量最高,分别为67.62~68.42 t·hm^(-2)和9.21~9.45 t·hm^(-2)·a^(-1),马尾松套种油茶和马尾松套种黄栀子模式较小,分别为31.96~36.24 t·hm^(-2)和4.09~4.16 t·hm^(-2)·a^(-1),马尾松纯林对照最小,分别为17.01 t·hm^(-2)和2.00 t·hm^(-2)·a^(-1)。土壤异养呼吸年通量从高到低依次为马尾松套种杨梅模式(7.41 t·hm^(-2)·a^(-1))>马尾松套种油茶模式(5.89 t·hm^(-2)·a^(-1))>马尾松套种无患子模式(5.86 t·hm^(-2)·a^(-1))>马尾松套种黄栀子模式(4.95 t·hm^(-2)·a^(-1))>马尾松纯林对照(2.45 t·hm^(-2)·a^(-1))。马尾松套种杨梅和马尾松套种无患子模式的年净生态系统碳平衡分别为2.04和3.27 t C·hm^(-2)·a^(-1),表现为"碳汇",马尾松套种油茶和马尾松套种黄栀子模式及马尾松纯林对照的年净生态系统碳平衡分别为-1.80、-0.80和-0.45 t C·hm^(-2)·a^(-1),表现为"碳源"。总体上,短期内马尾松低效林套种杨梅或无患子能够提升林分的固碳增汇效益。

We measured the annual net biomass growth,carbon content of each component and soil heterotrophic respiration in four low-efficiency interplanting patterns,i.e.,Pinus massoniana stands interplanting Myrica rubra,Sapindus mukurossi,Camellia oleifera and Gardenia jasminoides in Changting County,Fujian Province,with the aim to analyze the effects of interplanting patterns on carbon storage pattern and carbon balance of low-efficiency P.massoniana stand.The ranges of carbon content in different organs of M.rubra,S.mukurossi,C.oleifera,G.jasminoides and P.massoniana were 41.1%-50.1%,42.2%-50.6%,45.1%-48.9%,44.7%-49.6%and 46.1%-51.9%,respectively.Carbon content of the same organ significantly differed among tree species.The pattern of P.massoniana interplanting M.rubra and S.mukurossi had the highest carbon stock and annual net carbon increase reserves,with values of 67.62-68.42 t·hm^(-2)and 9.21-9.45 t·hm^(-2)·a^(-1),respectively.Followed by the lower pattern of C.oleifera,G.jasminoides,with values of 31.96-36.24 t·hm^(-2)and 4.09-4.16 t·hm^(-2)·a^(-1),respectively.The P.massoniana pure forest was the lowest,with values of 17.01 t·hm^(-2)and 2.00 t·hm^(-2)·a^(-1),respectively.Annual flux of soil heterotrophic respiration was following the order of P.massoniana interplanting M.rubra pattern(7.41 t·hm^(-2)·a^(-1))>P.massoniana interplanting C.oleifera pattern(5.89 t·hm^(-2)·a^(-1))>P.massoniana interplanting S.mukurossi pattern(5.86 t·hm^(-2)·a^(-1))>P.massoniana interplanting G.jasminoides pattern(4.95 t·hm^(-2)·a^(-1))>P.massoniana pure forest(2.45 t·hm^(-2)·a^(-1)).Annual net ecosystem carbon balance of P.massoniana interplanting M.rubra and S.mukurossi patterns were 2.04 and 3.27 t C·hm^(-2)·a^(-1),showing a"carbon sink"pattern.The net carbon balance in the patterns of P.massoniana interplanting C.oleifera and G.jasminoides along with P.massoniana pure forest were-1.80,-0.80 and-0.45 t C·hm^(-2)·a^(-1),which expressed a"carbon source"pattern.In the short-term,interplanting with M.rubra or S.mukurossi could improve the carbon income of the low-efficiency P.massoniana stand ecosystem.