生态环境学报
生態環境學報
생태배경학보
ECOLOGY AND ENVIRONMENT
2013年
11期
1774-1779
,共6页
活性有机碳%微生物生物量碳%易氧化态碳%轻组有机碳
活性有機碳%微生物生物量碳%易氧化態碳%輕組有機碳
활성유궤탄%미생물생물량탄%역양화태탄%경조유궤탄
active organic carbon%microbial biomass carbon%readily oxidizable carbon%light fraction carbon
测定了5种土地利用方式下（人工草地、围封样地、一年耕地、弃耕地、自由放牧样地）土壤有机碳、土壤微生物生物量碳、易氧化态碳和轻组有机碳组分含量特征，比较分析土地利用变化对典型草原土壤起源下土壤有机碳组分的变化。结果表明，1）人工草地土壤有机碳含量为(14.98±3.47) g·kg-1，围封样地的为(12.41±6.40) g·kg-1，一年耕地的为(12.20±5.59) g·kg-1，弃耕样地的为(10.39±5.08) g·kg-1，自由放牧样地的为(9.45±3.19) g·kg-1。人工草地土壤有机碳含量明显高于其他样地，围封样地和一年耕地的含量相似，自由放牧样地的含量最小。2）土壤微生物生物量碳、易氧化态碳和轻组有机碳的含量在不同土地利用方式下的变化趋势与土壤有机碳含量的变化趋势基本一致。土壤有机碳及其组分含量在土壤剖面上，随着土层深度的增加而逐渐降低。3）土壤微生物生物量碳、易氧化态碳和轻组有机碳的平均分配比率在不同类型样地范围分别为0.24%~0.66%、0.002%~0.019%和0.05%~0.25%，显示出各组分对土壤环境变化的敏感度不同，其中土壤微生物生物量碳更能反映土壤有机碳的早期变化，可以作为表征土壤有机碳变化和土壤肥力的敏感指标。
測定瞭5種土地利用方式下（人工草地、圍封樣地、一年耕地、棄耕地、自由放牧樣地）土壤有機碳、土壤微生物生物量碳、易氧化態碳和輕組有機碳組分含量特徵，比較分析土地利用變化對典型草原土壤起源下土壤有機碳組分的變化。結果錶明，1）人工草地土壤有機碳含量為(14.98±3.47) g·kg-1，圍封樣地的為(12.41±6.40) g·kg-1，一年耕地的為(12.20±5.59) g·kg-1，棄耕樣地的為(10.39±5.08) g·kg-1，自由放牧樣地的為(9.45±3.19) g·kg-1。人工草地土壤有機碳含量明顯高于其他樣地，圍封樣地和一年耕地的含量相似，自由放牧樣地的含量最小。2）土壤微生物生物量碳、易氧化態碳和輕組有機碳的含量在不同土地利用方式下的變化趨勢與土壤有機碳含量的變化趨勢基本一緻。土壤有機碳及其組分含量在土壤剖麵上，隨著土層深度的增加而逐漸降低。3）土壤微生物生物量碳、易氧化態碳和輕組有機碳的平均分配比率在不同類型樣地範圍分彆為0.24%~0.66%、0.002%~0.019%和0.05%~0.25%，顯示齣各組分對土壤環境變化的敏感度不同，其中土壤微生物生物量碳更能反映土壤有機碳的早期變化，可以作為錶徵土壤有機碳變化和土壤肥力的敏感指標。
측정료5충토지이용방식하（인공초지、위봉양지、일년경지、기경지、자유방목양지）토양유궤탄、토양미생물생물량탄、역양화태탄화경조유궤탄조분함량특정，비교분석토지이용변화대전형초원토양기원하토양유궤탄조분적변화。결과표명，1）인공초지토양유궤탄함량위(14.98±3.47) g·kg-1，위봉양지적위(12.41±6.40) g·kg-1，일년경지적위(12.20±5.59) g·kg-1，기경양지적위(10.39±5.08) g·kg-1，자유방목양지적위(9.45±3.19) g·kg-1。인공초지토양유궤탄함량명현고우기타양지，위봉양지화일년경지적함량상사，자유방목양지적함량최소。2）토양미생물생물량탄、역양화태탄화경조유궤탄적함량재불동토지이용방식하적변화추세여토양유궤탄함량적변화추세기본일치。토양유궤탄급기조분함량재토양부면상，수착토층심도적증가이축점강저。3）토양미생물생물량탄、역양화태탄화경조유궤탄적평균분배비솔재불동류형양지범위분별위0.24%~0.66%、0.002%~0.019%화0.05%~0.25%，현시출각조분대토양배경변화적민감도불동，기중토양미생물생물량탄경능반영토양유궤탄적조기변화，가이작위표정토양유궤탄변화화토양비력적민감지표。
To address how land use change affects soil organic carbon and its fractions, we sampled soil and measured contents of soil organic carbon, microbial biomass carbon, readily oxidizable carbon and light fraction carbon in five different land use types, i.e. artificial grassland (AG), grazing exclusion (GE), cropland (CP), fallow (FL) and free grazing grassland (FG). The content of soil organic carbon was (14.98 ± 3.47) g·kg-1 in AG, (12.41 ± 6.40) g·kg-1 in GE, (12.20 ± 5.59) g·kg-1 in CP, (10.39 ± 5.08) g·kg-1 in FL and (9.45 ± 3.19) g·kg-1 in FG. Soil organic carbon content in AG was significantly higher than that in other types of land use, and that in FG was the smallest among the five land use types. Soil organic carbon content was similar between GE and CP. The pattern of microbial biomass carbon, readily oxidizable carbon and light fraction carbon among the five land use types were similar to that of soil organic carbon. The contents of soil organic carbon and its fractions decreased gradually with increasing soil depth. In the five land use types, the ratio of microbial biomass carbon, readily oxidizable carbon and light fraction organic carbon to total soil organic carbon were 0.24%-0.66%, 0.002%-0.019% and 0.05%-0.25%, respectively. These results suggest that different fractions of soil organic carbon differ in the sensitivity to environmental change. Our results confirms that the index of soil microbial carbon can be regarded as the sensitive index indicating the change of soil organic carbon and soil fertility, which can reflect the change of soil organic carbon in the early stage.
