CAJ | 학술논문

选取湘东丘陵区花岗岩红壤4 种典型土地利用方式 (天然林以及由此转变而来的杉木人工林、板栗园和坡耕地), 挖掘土壤剖面深至1 m, 研究土壤颗粒有机碳 (POC) 及其组分 (粗颗粒有机碳: CPOC和细颗粒有机碳: FPOC ) 的储量, 分析POC及其组分与土壤有机碳 ( SOC) 的关系. 结果表明, 4种土地利用方式土壤POC储量介于5. 46~7. 17 t·hm-2 , 以浅层表土最高. 天然林改为其他土地利用方式后, POC储量仅仅在0~40 cm表土层显著降低.土壤CPOC和FPOC储量分别介于0. 23~1. 39 t·hm-2和0. 24~1. 57 t·hm-2. 天然林转变为其他利用方式后, CPOC储量未有显著变化, 但天然林改为板栗园和坡耕地后, FPOC储量大幅降低 (29% ~38%). 表土FPOC敏感地反映SOC储量的变化, 可用作土地利用过程中土壤C库缓慢变化的 "指示器". POC占SOC的比例 ( POC/SOC ) 介于6% ~8%, 天然林和杉木人工林POC/SOC在40 cm以下底土中迅速降低, 但板栗园和坡耕地土壤剖面上的POC/SOC差别不大. 天然林和杉木人工林土壤POC中以FPOC为主, 而板栗园和坡耕地皆以CPOC为主.本研究表明, 有必要区别看待POC及其组分对土地利用变化响应的敏感度.
선취상동구릉구화강암홍양4 충전형토지이용방식 (천연림이급유차전변이래적삼목인공림、 판률완화파경지), 알굴토양부면심지1 m, 연구토양과립유궤탄 (POC) 급기조분 (조과립유궤탄: CPOC화세과립유궤탄: FPOC ) 적저량, 분석POC급기조분여토양유궤탄 ( SOC) 적관계. 결과표명, 4충토지이용방식토양POC저량개우5. 46~7. 17 t·hm-2 , 이천층표토최고. 천연림개위기타토지이용방식후, POC저량부부재0~40 cm표토층현저강저.토양CPOC화FPOC저량분별개우0. 23~1. 39 t·hm-2화0. 24~1. 57 t·hm-2. 천연림전변위기타이용방식후, CPOC저량미유현저변화, 단천연림개위판률완화파경지후, FPOC저량대폭강저 (29% ~38%). 표토FPOC민감지반영SOC저량적변화, 가용작토지이용과정중토양C고완만변화적 "지시기". POC점SOC적비례 ( POC/SOC ) 개우6% ~8%, 천연림화삼목인공림POC/SOC재40 cm이하저토중신속강저, 단판률완화파경지토양부면상적POC/SOC차별불대. 천연림화삼목인공림토양POC중이FPOC위주, 이판률완화파경지개이CPOC위주.본연구표명, 유필요구별간대POC급기조분대토지이용변화향응적민감도.
Soils derived from granite under different land uses ( natural forest, Chinese fir plantation, Chinese chestnut orchard, and sloping tillage) in subtropical China were selected, and the particulate organic C ( POC) and its components, including coarse particulate organic C ( CPOC) and fine partic-ulate organic C ( FPOC) , along 0~1 m depth were evaluated. Results showed that POC, CPOC, and FPOC stock were in the range of 5. 46~7. 17 t·hm-2 , 0. 23~1. 39 t·hm-2 , and 0. 24~1. 57 t· hm-2 at 0~1 m soil depth, respectively, and all of them increased with increasing depth. It was found that, after the conversion of natural forest into other land uses, POC stock was only decreased signifi- cantly at 0~40 cm depth. CPOC stock was not affected, while FPOC stock in 0~20 cm topsoil de-creased by 21%, 53%, and 51% after the conversion of natural forest into plantation, orchard, and sloping tillage, respectively. This implied that the reduction of POC stock after land use change mainly resulted from the loss of topsoil FPOC, which, consequently, could be used as a sensitive indicator of detecting SOC changes. Proportion of POC to SOC ( POC/SOC) varied from 6% to 8%, and was re-duced at 0 ~40 cm depth after converting into orchard and sloping tillage. POC was dominated by FPOC for natural forest and Chinese fir plantation and by CPOC for Chinese chestnut orchard and slop-ing tillage. It is necessary to differentiate response of POC components to land use change.