摘要
采用等质量计算土壤碳储量的方法,研究了不同开垦年限对碱化草地0~100 cm土层土壤有机碳、无机碳和总碳储量的影响。结果表明:开垦24年后,耕地与天然草地相比0~100 cm土层土壤平均有机碳含量下降了11.22%,无机碳含量上升了27.47%;草地开垦以后,0~100 cm土层土壤有机碳储量以0.88 Mg hm^(-2)a^(-1)的速率下降,土壤无机碳储量以8.18 Mg hm^(-2)a^(-1)的速率增加;无机碳储量的增加弥补了有机碳储量的下降,从而使得0~100 cm土层土壤总碳储量以7.30 Mg hm^(-2)a^(-1)的速率增加。与等体积法得到的结果相比,应用等质量法估算得到的结果提高了土壤的碳库储量,使得0~100 cm土层土壤有机碳储量的损失速率降低了2.75 Mg hm^(-2)a^(-1),而土壤无机碳储量的截获速率则提高了7.65 Mg hm^(-2)a^(-1)。以上结果表明,在估算富含无机碳的土壤碳库时应将土壤无机碳库考虑在内,而且在土地利用方式改变后,将土壤容重考虑在内的等质量法估算土壤碳库储量可能比等体积法更合适。
This study investigated the changes in soil organic carbon （SOC）, soil inorganic carbon （SIC） and soil total carbon （STC） storage at 0 - 100 cm soil depth using an equivalent mass method along a cultivation chronosequence for grassland reclaimed for 0, 1, 7, 17 and 24 years in Songnen grassland. Results showed that long term cultivation had great effects on soll carbon concentration and storage. The average of SOC concentration at 0 - 100 cm depth of croplands decreased by 11.22%, while SIC concentration increased by 27.47% compared with grassland. SIC made an important contribution to STC storage. SOC storage decreased slightly at 0 - 100 cm soil depth with an average loss rate of 0.88 Mg hm^-2a^-1, while SIC storage increased rapidly with a sequestrated rate of 8.18 Mg hm^-2a^-1 after grassland conversion to cropland, and thus STC storage increased with an average sequestrated rate of 7.30 Mg hm^-2a^-1 at 0 - 100 cm soil depth due to the increase of SIC after cultivation. Compared with the results of equivalent depth method, the loss rate of SOC storage at 0 - 100 cm soil depth using equivalent mass method decreased by 2.75 Mg hm^-2a^-1, while the sequestrated rate of SIC storage increased by 7.65 Mg hm^-2a^-1. Results indicated that dynamics of SIC should be included in the carbon storage estimates and the equivalent mass method was more suitable than equivalent depth method to consider the dynamics of soil mass after land-use change.
出处
《土壤通报》
CAS
北大核心
2017年第1期127-133,共7页
Chinese Journal of Soil Science
基金
国家自然科学基金项目(31500446)资助
关键词
土壤有机碳
土壤无机碳
土地利用变化
松嫩草地
Soil organic carbon
Soil inorganic carbon
Land-use change
Songnen grassland
