格氏栲和杉木人工林地下碳分配  

Total belowground carbon allocation in Castanopsis kawakamii and Chinese fir plantations in subtropical area of China

作　　者：陈光水[1] 杨玉盛[1] 钱伟[1] 高人[1] 牛志鹏[2] 韩永刚[2] 张有利[2] 

机构地区：[1]福建师范大学地理科学学院,福州350007 [2]福建农林大学林学院,福州350002

出　　处：《生态学报》2005年第11期2824-2829,共6页Acta Ecologica Sinica

基　　金：国家教育部高等学校优秀青年教师教学科研奖励计划资助项目;国家自然科学基金资助项目(30300272);福建省自然科学基金资助项目(B0310014)~~

摘　　要：通过对福建三明36年生的格氏栲人工林和杉木人工林林木地下C分配(TBCA)进行研究,结果表明,由分室累加法直接测定的格氏栲和杉木人工林的TBCA分别为8.426和4.040 t C.hm-2.-a 1。在格氏栲和杉木人工林TBCA组成中,根系净生产量和根系呼吸各约占50%;在根系年净生产量中,细根年净生产量和粗根年净生产量各约占75%和25%。而格氏栲和杉木人工林的细根年C归还量则均约占各自TBCA的1/3(分别为33%和36%)。在假设地下C库处于稳定状态时,由C平衡法计算的格氏栲和杉木人工林的TBCA(分别为6.039t C.hm-2.-a 1和2.987 t C.hm-2.-a 1)低于分室累加法,这与两种人工林地下C库尚未达到稳定状态有关。利用R a ich and N ade lhoffer全球模式方程推算的格氏栲和杉木人工林的TBCA(分别为9.771t C.hm-2.a-1和5.344 t C.hm-2.-a 1)则高于分室累加法,这与全球模式方程只是一种全球尺度规律有关。Total belowground carbon allocation （TBCA） is defined as that carbon allocated belowground by plants to produce coarse and fine roots, root respiration, and root exudates and mycorrhizae. TBCA can be a large fraction of gross primary production, sometimes exceeding aboveground net primary production. Quantifying the individual components of TBCA is challenging because belowground C processes are intimately associated with the soil matrix. Thus, our understanding of the factors that control TBCA is poor, though increases in the numbers of experiments will help clarify the major role of TBCA in the C balance of terrestrial ecosystems. TBCA and its components were determined between two 36-year-old plantations of Castanopsis kawakamii （CK） and Cunninghamia lanceolata （Chinese fir, CF） in sanming, Fujian. We established root-free trenched plots to determined root respiration （RR）, utilized sequential coring method to estimate fine-root production （NPPfr）, and developed allometric equation to determine coarse root production （NPPcr）. TBCA was calculated by three methods, viz. , the component-integrated method （TBCAcr）, the carbon balance method （TBCAcB）, and the global trend equation （TBCAGTE）. TBCAca was estimated 8. 426 t C· hm^-2· a^-1 and 4. 040 t C· hm^-2· a^-1 for the CK and the CF, respectively. TBCAcr was allocated evenly between root production and respiration, and NPPfr and NPP. contributed to 75% and 25% of root production for the two plantations.About one third of TBCAcI was converted into root detritus. TBCAcB was calculated as 6. 039 t C· hm^-2· a^-1 and 2. 987 t C· hm^-2· a^-1, and TBCAcTE was estimated as 9. 771 t C· hm^-2· a^-1 and 5. 344 t C· hm^-2· a^-1 for the CK and the CF, respectively. Difference between TBCACI and TBCACB might be resulted from the non-steady state in the belowground C pool of the two plantations. The discrepancy between TBCACI and TBCAGTE implicated that the global trend equation proposed by Raich and Nadelhoffer might fa

关 键 词：格氏栲 杉木 地下C分配 根系生产力 根系呼吸 

分 类 号：S792.17[农业科学—林木遗传育种] S791.27[农业科学—林学]